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[PATCH v1 3/3] CatCache expiration feature. 72+ messages / 4 participants [nested] [flat]
* [PATCH v1 3/3] CatCache expiration feature. @ 2020-01-10 06:08 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-01-10 06:08 UTC (permalink / raw) This adds the catcache expiration feature to the catcache mechanism. Current catcache doesn't remove an entry and there's a case where many hash entries occupy large amont of memory , being not accessed ever after. This can be a quite serious issue on the cases of long-running sessions. The expiration feature keeps process memory usage below certain amount, in exchange of some extent of degradation if it is turned on. --- src/backend/utils/cache/catcache.c | 343 +++++++++++++++++++++++++++-- 1 file changed, 326 insertions(+), 17 deletions(-) diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index a4e3676a89..29bc980d8e 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -72,10 +72,11 @@ static CatCacheHeader *CacheHdr = NULL; /* Clock for the last accessed time of a catcache entry. */ TimestampTz catcacheclock = 0; -static inline HeapTuple SearchCatCacheInternal(CatCache *cache, - int nkeys, - Datum v1, Datum v2, - Datum v3, Datum v4); +/* basic catcache search functions */ +static inline HeapTuple SearchCatCacheInternalb(CatCache *cache, + int nkeys, + Datum v1, Datum v2, + Datum v3, Datum v4); static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, int nkeys, @@ -93,6 +94,23 @@ static HeapTuple SearchCatCache3b(CatCache *cache, static HeapTuple SearchCatCache4b(CatCache *cache, Datum v1, Datum v2, Datum v3, Datum v4); +/* catcache search functions with expiration feature */ +static inline HeapTuple SearchCatCacheInternale(CatCache *cache, + int nkeys, + Datum v1, Datum v2, + Datum v3, Datum v4); + +static HeapTuple SearchCatCachee(CatCache *cache, + Datum v1, Datum v2, Datum v3, Datum v4); +static HeapTuple SearchCatCache1e(CatCache *cache, Datum v1); +static HeapTuple SearchCatCache2e(CatCache *cache, Datum v1, Datum v2); +static HeapTuple SearchCatCache3e(CatCache *cache, + Datum v1, Datum v2, Datum v3); +static HeapTuple SearchCatCache4e(CatCache *cache, + Datum v1, Datum v2, Datum v3, Datum v4); + +static bool CatCacheCleanupOldEntries(CatCache *cp); + static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); static uint32 CatalogCacheComputeTupleHashValue(CatCache *cache, int nkeys, @@ -125,13 +143,35 @@ static SearchCatCacheFuncsType catcache_base = { SearchCatCache4b }; +static SearchCatCacheFuncsType catcache_expire = { + SearchCatCachee, + SearchCatCache1e, + SearchCatCache2e, + SearchCatCache3e, + SearchCatCache4e +}; + SearchCatCacheFuncsType *SearchCatCacheFuncs = NULL; +/* set catcache function set according to guc variables */ +static void +set_catcache_functions(void) +{ + if (catalog_cache_prune_min_age < 0) + SearchCatCacheFuncs = &catcache_base; + else + SearchCatCacheFuncs = &catcache_expire; +} + + /* GUC assign function */ void assign_catalog_cache_prune_min_age(int newval, void *extra) { catalog_cache_prune_min_age = newval; + + /* choose corresponding function set */ + set_catcache_functions(); } /* @@ -837,7 +877,7 @@ InitCatCache(int id, slist_init(&CacheHdr->ch_caches); CacheHdr->ch_ntup = 0; - SearchCatCacheFuncs = &catcache_base; + set_catcache_functions(); #ifdef CATCACHE_STATS /* set up to dump stats at backend exit */ @@ -900,6 +940,10 @@ RehashCatCache(CatCache *cp) int newnbuckets; int i; + /* try removing old entries before expanding hash */ + if (CatCacheCleanupOldEntries(cp)) + return; + elog(DEBUG1, "rehashing catalog cache id %d for %s; %d tups, %d buckets", cp->id, cp->cc_relname, cp->cc_ntup, cp->cc_nbuckets); @@ -1187,7 +1231,7 @@ SearchCatCacheb(CatCache *cache, Datum v3, Datum v4) { - return SearchCatCacheInternal(cache, cache->cc_nkeys, v1, v2, v3, v4); + return SearchCatCacheInternalb(cache, cache->cc_nkeys, v1, v2, v3, v4); } @@ -1201,7 +1245,7 @@ static HeapTuple SearchCatCache1b(CatCache *cache, Datum v1) { - return SearchCatCacheInternal(cache, 1, v1, 0, 0, 0); + return SearchCatCacheInternalb(cache, 1, v1, 0, 0, 0); } @@ -1209,7 +1253,7 @@ static HeapTuple SearchCatCache2b(CatCache *cache, Datum v1, Datum v2) { - return SearchCatCacheInternal(cache, 2, v1, v2, 0, 0); + return SearchCatCacheInternalb(cache, 2, v1, v2, 0, 0); } @@ -1217,7 +1261,7 @@ static HeapTuple SearchCatCache3b(CatCache *cache, Datum v1, Datum v2, Datum v3) { - return SearchCatCacheInternal(cache, 3, v1, v2, v3, 0); + return SearchCatCacheInternalb(cache, 3, v1, v2, v3, 0); } @@ -1225,19 +1269,19 @@ static HeapTuple SearchCatCache4b(CatCache *cache, Datum v1, Datum v2, Datum v3, Datum v4) { - return SearchCatCacheInternal(cache, 4, v1, v2, v3, v4); + return SearchCatCacheInternalb(cache, 4, v1, v2, v3, v4); } /* - * Work-horse for SearchCatCache/SearchCatCacheN. + * Work-horse for SearchCatCacheb/SearchCatCacheNb. */ static inline HeapTuple -SearchCatCacheInternal(CatCache *cache, - int nkeys, - Datum v1, - Datum v2, - Datum v3, - Datum v4) +SearchCatCacheInternalb(CatCache *cache, + int nkeys, + Datum v1, + Datum v2, + Datum v3, + Datum v4) { Datum arguments[CATCACHE_MAXKEYS]; uint32 hashValue; @@ -1462,6 +1506,269 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * SearchCatCache with entry pruning + * + * These functions works the same way with SearchCatCacheNb() functions except + * that less-used entries are removed following catalog_cache_prune_min_age + * setting. + */ +static HeapTuple +SearchCatCachee(CatCache *cache, + Datum v1, + Datum v2, + Datum v3, + Datum v4) +{ + return SearchCatCacheInternale(cache, cache->cc_nkeys, v1, v2, v3, v4); +} + + +/* + * SearchCatCacheN() are SearchCatCache() versions for a specific number of + * arguments. The compiler can inline the body and unroll loops, making them a + * bit faster than SearchCatCache(). + */ + +static HeapTuple +SearchCatCache1e(CatCache *cache, + Datum v1) +{ + return SearchCatCacheInternale(cache, 1, v1, 0, 0, 0); +} + + +static HeapTuple +SearchCatCache2e(CatCache *cache, + Datum v1, Datum v2) +{ + return SearchCatCacheInternale(cache, 2, v1, v2, 0, 0); +} + + +static HeapTuple +SearchCatCache3e(CatCache *cache, + Datum v1, Datum v2, Datum v3) +{ + return SearchCatCacheInternale(cache, 3, v1, v2, v3, 0); +} + + +static HeapTuple +SearchCatCache4e(CatCache *cache, + Datum v1, Datum v2, Datum v3, Datum v4) +{ + return SearchCatCacheInternale(cache, 4, v1, v2, v3, v4); +} + +/* + * Work-horse for SearchCatCachee/SearchCatCacheNe. + */ +static inline HeapTuple +SearchCatCacheInternale(CatCache *cache, + int nkeys, + Datum v1, + Datum v2, + Datum v3, + Datum v4) +{ + Datum arguments[CATCACHE_MAXKEYS]; + uint32 hashValue; + Index hashIndex; + dlist_iter iter; + dlist_head *bucket; + CatCTup *ct; + + /* Make sure we're in an xact, even if this ends up being a cache hit */ + Assert(IsTransactionState()); + + Assert(cache->cc_nkeys == nkeys); + + /* + * one-time startup overhead for each cache + */ + if (unlikely(cache->cc_tupdesc == NULL)) + CatalogCacheInitializeCache(cache); + +#ifdef CATCACHE_STATS + cache->cc_searches++; +#endif + + /* Initialize local parameter array */ + arguments[0] = v1; + arguments[1] = v2; + arguments[2] = v3; + arguments[3] = v4; + + /* + * find the hash bucket in which to look for the tuple + */ + hashValue = CatalogCacheComputeHashValue(cache, nkeys, v1, v2, v3, v4); + hashIndex = HASH_INDEX(hashValue, cache->cc_nbuckets); + + /* + * scan the hash bucket until we find a match or exhaust our tuples + * + * Note: it's okay to use dlist_foreach here, even though we modify the + * dlist within the loop, because we don't continue the loop afterwards. + */ + bucket = &cache->cc_bucket[hashIndex]; + dlist_foreach(iter, bucket) + { + ct = dlist_container(CatCTup, cache_elem, iter.cur); + + if (ct->dead) + continue; /* ignore dead entries */ + + if (ct->hash_value != hashValue) + continue; /* quickly skip entry if wrong hash val */ + + if (!CatalogCacheCompareTuple(cache, nkeys, ct->keys, arguments)) + continue; + + /* + * We found a match in the cache. Move it to the front of the list + * for its hashbucket, in order to speed subsequent searches. (The + * most frequently accessed elements in any hashbucket will tend to be + * near the front of the hashbucket's list.) + */ + dlist_move_head(bucket, &ct->cache_elem); + + /* + * Prolong life of this entry. Since we want run as less instructions + * as possible and want the branch be stable for performance reasons, + * we don't give a strict cap on the counter. All numbers above 1 will + * be regarded as 2 in CatCacheCleanupOldEntries(). + */ + ct->naccess++; + if (unlikely(ct->naccess == 0)) + ct->naccess = 2; + ct->lastaccess = catcacheclock; + + /* + * If it's a positive entry, bump its refcount and return it. If it's + * negative, we can report failure to the caller. + */ + if (!ct->negative) + { + ResourceOwnerEnlargeCatCacheRefs(CurrentResourceOwner); + ct->refcount++; + ResourceOwnerRememberCatCacheRef(CurrentResourceOwner, &ct->tuple); + + CACHE_elog(DEBUG2, "SearchCatCache(%s): found in bucket %d", + cache->cc_relname, hashIndex); + +#ifdef CATCACHE_STATS + cache->cc_hits++; +#endif + + return &ct->tuple; + } + else + { + CACHE_elog(DEBUG2, "SearchCatCache(%s): found neg entry in bucket %d", + cache->cc_relname, hashIndex); + +#ifdef CATCACHE_STATS + cache->cc_neg_hits++; +#endif + + return NULL; + } + } + + return SearchCatCacheMiss(cache, nkeys, hashValue, hashIndex, v1, v2, v3, v4); +} + +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + long age; + int us; + + /* Return immediately if disabled */ + if (catalog_cache_prune_min_age < 0) + return false; + + /* Don't scan the hash when we know we don't have prunable entries */ + TimestampDifference(cp->cc_oldest_ts, catcacheclock, &age, &us); + if (age < catalog_cache_prune_min_age) + return false; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + /* + * Calculate the duration from the time from the last access + * to the "current" time. catcacheclock is updated + * per-statement basis and additionaly udpated periodically + * during a long running query. + */ + TimestampDifference(ct->lastaccess, catcacheclock, &age, &us); + + if (age > catalog_cache_prune_min_age) + { + /* + * Entries that are not accessed after the last pruning + * are removed in that seconds, and their lives are + * prolonged according to how many times they are accessed + * up to three times of the duration. We don't try shrink + * buckets since pruning effectively caps catcache + * expansion in the long term. + */ + if (ct->naccess > 2) + ct->naccess = 1; + else if (ct->naccess > 0) + ct->naccess--; + else + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't update oldest_ts by removed entry */ + continue; + } + } + } + + /* update oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + + /* * ReleaseCatCache * @@ -1925,6 +2232,8 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->naccess = 0; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); -- 2.23.0 ----Next_Part(Wed_Jan_22_14_38_19_2020_534)-- Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="catcache-benchmark-extension.patch.txt" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v2 3/3] CatCache expiration feature. @ 2020-01-10 06:08 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-01-10 06:08 UTC (permalink / raw) This adds the catcache expiration feature to the catcache mechanism. Current catcache doesn't remove an entry and there's a case where many hash entries occupy large amont of memory , being not accessed ever after. This can be a quite serious issue on the cases of long-running sessions. The expiration feature keeps process memory usage below certain amount, in exchange of some extent of degradation if it is turned on. --- src/backend/utils/cache/catcache.c | 344 +++++++++++++++++++++++++++-- 1 file changed, 327 insertions(+), 17 deletions(-) diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index e047389e16..be4c90af7d 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -72,10 +73,11 @@ static CatCacheHeader *CacheHdr = NULL; /* Clock for the last accessed time of a catcache entry. */ TimestampTz catcacheclock = 0; -static inline HeapTuple SearchCatCacheInternal(CatCache *cache, - int nkeys, - Datum v1, Datum v2, - Datum v3, Datum v4); +/* basic catcache search functions */ +static inline HeapTuple SearchCatCacheInternalb(CatCache *cache, + int nkeys, + Datum v1, Datum v2, + Datum v3, Datum v4); static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, int nkeys, @@ -93,6 +95,23 @@ static HeapTuple SearchCatCache3b(CatCache *cache, static HeapTuple SearchCatCache4b(CatCache *cache, Datum v1, Datum v2, Datum v3, Datum v4); +/* catcache search functions with expiration feature */ +static inline HeapTuple SearchCatCacheInternale(CatCache *cache, + int nkeys, + Datum v1, Datum v2, + Datum v3, Datum v4); + +static HeapTuple SearchCatCachee(CatCache *cache, + Datum v1, Datum v2, Datum v3, Datum v4); +static HeapTuple SearchCatCache1e(CatCache *cache, Datum v1); +static HeapTuple SearchCatCache2e(CatCache *cache, Datum v1, Datum v2); +static HeapTuple SearchCatCache3e(CatCache *cache, + Datum v1, Datum v2, Datum v3); +static HeapTuple SearchCatCache4e(CatCache *cache, + Datum v1, Datum v2, Datum v3, Datum v4); + +static bool CatCacheCleanupOldEntries(CatCache *cp); + static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); static uint32 CatalogCacheComputeTupleHashValue(CatCache *cache, int nkeys, @@ -125,13 +144,35 @@ static SearchCatCacheFuncsType catcache_base = { SearchCatCache4b }; +static SearchCatCacheFuncsType catcache_expire = { + SearchCatCachee, + SearchCatCache1e, + SearchCatCache2e, + SearchCatCache3e, + SearchCatCache4e +}; + SearchCatCacheFuncsType *SearchCatCacheFuncs = NULL; +/* set catcache function set according to guc variables */ +static void +set_catcache_functions(void) +{ + if (catalog_cache_prune_min_age < 0) + SearchCatCacheFuncs = &catcache_base; + else + SearchCatCacheFuncs = &catcache_expire; +} + + /* GUC assign function */ void assign_catalog_cache_prune_min_age(int newval, void *extra) { catalog_cache_prune_min_age = newval; + + /* choose corresponding function set */ + set_catcache_functions(); } /* @@ -837,7 +878,7 @@ InitCatCache(int id, slist_init(&CacheHdr->ch_caches); CacheHdr->ch_ntup = 0; - SearchCatCacheFuncs = &catcache_base; + set_catcache_functions(); #ifdef CATCACHE_STATS /* set up to dump stats at backend exit */ @@ -900,6 +941,10 @@ RehashCatCache(CatCache *cp) int newnbuckets; int i; + /* try removing old entries before expanding hash */ + if (CatCacheCleanupOldEntries(cp)) + return; + elog(DEBUG1, "rehashing catalog cache id %d for %s; %d tups, %d buckets", cp->id, cp->cc_relname, cp->cc_ntup, cp->cc_nbuckets); @@ -1187,7 +1232,7 @@ SearchCatCacheb(CatCache *cache, Datum v3, Datum v4) { - return SearchCatCacheInternal(cache, cache->cc_nkeys, v1, v2, v3, v4); + return SearchCatCacheInternalb(cache, cache->cc_nkeys, v1, v2, v3, v4); } @@ -1201,7 +1246,7 @@ static HeapTuple SearchCatCache1b(CatCache *cache, Datum v1) { - return SearchCatCacheInternal(cache, 1, v1, 0, 0, 0); + return SearchCatCacheInternalb(cache, 1, v1, 0, 0, 0); } @@ -1209,7 +1254,7 @@ static HeapTuple SearchCatCache2b(CatCache *cache, Datum v1, Datum v2) { - return SearchCatCacheInternal(cache, 2, v1, v2, 0, 0); + return SearchCatCacheInternalb(cache, 2, v1, v2, 0, 0); } @@ -1217,7 +1262,7 @@ static HeapTuple SearchCatCache3b(CatCache *cache, Datum v1, Datum v2, Datum v3) { - return SearchCatCacheInternal(cache, 3, v1, v2, v3, 0); + return SearchCatCacheInternalb(cache, 3, v1, v2, v3, 0); } @@ -1225,19 +1270,19 @@ static HeapTuple SearchCatCache4b(CatCache *cache, Datum v1, Datum v2, Datum v3, Datum v4) { - return SearchCatCacheInternal(cache, 4, v1, v2, v3, v4); + return SearchCatCacheInternalb(cache, 4, v1, v2, v3, v4); } /* - * Work-horse for SearchCatCache/SearchCatCacheN. + * Work-horse for SearchCatCacheb/SearchCatCacheNb. */ static inline HeapTuple -SearchCatCacheInternal(CatCache *cache, - int nkeys, - Datum v1, - Datum v2, - Datum v3, - Datum v4) +SearchCatCacheInternalb(CatCache *cache, + int nkeys, + Datum v1, + Datum v2, + Datum v3, + Datum v4) { Datum arguments[CATCACHE_MAXKEYS]; uint32 hashValue; @@ -1462,6 +1507,269 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * SearchCatCache with entry pruning + * + * These functions works the same way with SearchCatCacheNb() functions except + * that less-used entries are removed following catalog_cache_prune_min_age + * setting. + */ +static HeapTuple +SearchCatCachee(CatCache *cache, + Datum v1, + Datum v2, + Datum v3, + Datum v4) +{ + return SearchCatCacheInternale(cache, cache->cc_nkeys, v1, v2, v3, v4); +} + + +/* + * SearchCatCacheN() are SearchCatCache() versions for a specific number of + * arguments. The compiler can inline the body and unroll loops, making them a + * bit faster than SearchCatCache(). + */ + +static HeapTuple +SearchCatCache1e(CatCache *cache, + Datum v1) +{ + return SearchCatCacheInternale(cache, 1, v1, 0, 0, 0); +} + + +static HeapTuple +SearchCatCache2e(CatCache *cache, + Datum v1, Datum v2) +{ + return SearchCatCacheInternale(cache, 2, v1, v2, 0, 0); +} + + +static HeapTuple +SearchCatCache3e(CatCache *cache, + Datum v1, Datum v2, Datum v3) +{ + return SearchCatCacheInternale(cache, 3, v1, v2, v3, 0); +} + + +static HeapTuple +SearchCatCache4e(CatCache *cache, + Datum v1, Datum v2, Datum v3, Datum v4) +{ + return SearchCatCacheInternale(cache, 4, v1, v2, v3, v4); +} + +/* + * Work-horse for SearchCatCachee/SearchCatCacheNe. + */ +static inline HeapTuple +SearchCatCacheInternale(CatCache *cache, + int nkeys, + Datum v1, + Datum v2, + Datum v3, + Datum v4) +{ + Datum arguments[CATCACHE_MAXKEYS]; + uint32 hashValue; + Index hashIndex; + dlist_iter iter; + dlist_head *bucket; + CatCTup *ct; + + /* Make sure we're in an xact, even if this ends up being a cache hit */ + Assert(IsTransactionState()); + + Assert(cache->cc_nkeys == nkeys); + + /* + * one-time startup overhead for each cache + */ + if (unlikely(cache->cc_tupdesc == NULL)) + CatalogCacheInitializeCache(cache); + +#ifdef CATCACHE_STATS + cache->cc_searches++; +#endif + + /* Initialize local parameter array */ + arguments[0] = v1; + arguments[1] = v2; + arguments[2] = v3; + arguments[3] = v4; + + /* + * find the hash bucket in which to look for the tuple + */ + hashValue = CatalogCacheComputeHashValue(cache, nkeys, v1, v2, v3, v4); + hashIndex = HASH_INDEX(hashValue, cache->cc_nbuckets); + + /* + * scan the hash bucket until we find a match or exhaust our tuples + * + * Note: it's okay to use dlist_foreach here, even though we modify the + * dlist within the loop, because we don't continue the loop afterwards. + */ + bucket = &cache->cc_bucket[hashIndex]; + dlist_foreach(iter, bucket) + { + ct = dlist_container(CatCTup, cache_elem, iter.cur); + + if (ct->dead) + continue; /* ignore dead entries */ + + if (ct->hash_value != hashValue) + continue; /* quickly skip entry if wrong hash val */ + + if (!CatalogCacheCompareTuple(cache, nkeys, ct->keys, arguments)) + continue; + + /* + * We found a match in the cache. Move it to the front of the list + * for its hashbucket, in order to speed subsequent searches. (The + * most frequently accessed elements in any hashbucket will tend to be + * near the front of the hashbucket's list.) + */ + dlist_move_head(bucket, &ct->cache_elem); + + /* + * Prolong life of this entry. Since we want run as less instructions + * as possible and want the branch be stable for performance reasons, + * we don't give a strict cap on the counter. All numbers above 1 will + * be regarded as 2 in CatCacheCleanupOldEntries(). + */ + ct->naccess++; + if (unlikely(ct->naccess == 0)) + ct->naccess = 2; + ct->lastaccess = catcacheclock; + + /* + * If it's a positive entry, bump its refcount and return it. If it's + * negative, we can report failure to the caller. + */ + if (!ct->negative) + { + ResourceOwnerEnlargeCatCacheRefs(CurrentResourceOwner); + ct->refcount++; + ResourceOwnerRememberCatCacheRef(CurrentResourceOwner, &ct->tuple); + + CACHE_elog(DEBUG2, "SearchCatCache(%s): found in bucket %d", + cache->cc_relname, hashIndex); + +#ifdef CATCACHE_STATS + cache->cc_hits++; +#endif + + return &ct->tuple; + } + else + { + CACHE_elog(DEBUG2, "SearchCatCache(%s): found neg entry in bucket %d", + cache->cc_relname, hashIndex); + +#ifdef CATCACHE_STATS + cache->cc_neg_hits++; +#endif + + return NULL; + } + } + + return SearchCatCacheMiss(cache, nkeys, hashValue, hashIndex, v1, v2, v3, v4); +} + +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + long age; + int us; + + /* Return immediately if disabled */ + if (catalog_cache_prune_min_age < 0) + return false; + + /* Don't scan the hash when we know we don't have prunable entries */ + TimestampDifference(cp->cc_oldest_ts, catcacheclock, &age, &us); + if (age < catalog_cache_prune_min_age) + return false; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + /* + * Calculate the duration from the time from the last access + * to the "current" time. catcacheclock is updated + * per-statement basis and additionaly udpated periodically + * during a long running query. + */ + TimestampDifference(ct->lastaccess, catcacheclock, &age, &us); + + if (age > catalog_cache_prune_min_age) + { + /* + * Entries that are not accessed after the last pruning + * are removed in that seconds, and their lives are + * prolonged according to how many times they are accessed + * up to three times of the duration. We don't try shrink + * buckets since pruning effectively caps catcache + * expansion in the long term. + */ + if (ct->naccess > 2) + ct->naccess = 1; + else if (ct->naccess > 0) + ct->naccess--; + else + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't update oldest_ts by removed entry */ + continue; + } + } + } + + /* update oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + + /* * ReleaseCatCache * @@ -1925,6 +2233,8 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->naccess = 0; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); -- 2.18.4 ----Next_Part(Thu_Oct__1_16_47_18_2020_205)---- ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v3 3/3] CatCache expiration feature. @ 2020-01-10 06:08 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-01-10 06:08 UTC (permalink / raw) This adds the catcache expiration feature to the catcache mechanism. Current catcache doesn't remove an entry and there's a case where many hash entries occupy large amont of memory , being not accessed ever after. This can be a quite serious issue on the cases of long-running sessions. The expiration feature keeps process memory usage below certain amount, in exchange of some extent of degradation if it is turned on. --- src/backend/utils/cache/catcache.c | 219 +++++++++++++++++++++++++++-- 1 file changed, 211 insertions(+), 8 deletions(-) diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index 7ac59bcdd6..a07b434fb6 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -72,7 +73,8 @@ static CatCacheHeader *CacheHdr = NULL; /* Clock for the last accessed time of a catcache entry. */ TimestampTz catcacheclock = 0; -static inline HeapTuple SearchCatCacheInternal(CatCache *cache, +static inline HeapTuple SearchCatCacheInternal(bool do_expire, + CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -93,6 +95,17 @@ static HeapTuple SearchCatCache3b(CatCache *cache, static HeapTuple SearchCatCache4b(CatCache *cache, Datum v1, Datum v2, Datum v3, Datum v4); +static HeapTuple SearchCatCachee(CatCache *cache, + Datum v1, Datum v2, Datum v3, Datum v4); +static HeapTuple SearchCatCache1e(CatCache *cache, Datum v1); +static HeapTuple SearchCatCache2e(CatCache *cache, Datum v1, Datum v2); +static HeapTuple SearchCatCache3e(CatCache *cache, + Datum v1, Datum v2, Datum v3); +static HeapTuple SearchCatCache4e(CatCache *cache, + Datum v1, Datum v2, Datum v3, Datum v4); + +static bool CatCacheCleanupOldEntries(CatCache *cp); + static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); static uint32 CatalogCacheComputeTupleHashValue(CatCache *cache, int nkeys, @@ -125,13 +138,35 @@ static SearchCatCacheFuncsType catcache_base = { SearchCatCache4b }; +static SearchCatCacheFuncsType catcache_expire = { + SearchCatCachee, + SearchCatCache1e, + SearchCatCache2e, + SearchCatCache3e, + SearchCatCache4e +}; + SearchCatCacheFuncsType *SearchCatCacheFuncs = NULL; +/* set catcache function set according to guc variables */ +static void +set_catcache_functions(void) +{ + if (catalog_cache_prune_min_age < 0) + SearchCatCacheFuncs = &catcache_base; + else + SearchCatCacheFuncs = &catcache_expire; +} + + /* GUC assign function */ void assign_catalog_cache_prune_min_age(int newval, void *extra) { catalog_cache_prune_min_age = newval; + + /* choose corresponding function set */ + set_catcache_functions(); } /* @@ -837,7 +872,7 @@ InitCatCache(int id, slist_init(&CacheHdr->ch_caches); CacheHdr->ch_ntup = 0; - SearchCatCacheFuncs = &catcache_base; + set_catcache_functions(); #ifdef CATCACHE_STATS /* set up to dump stats at backend exit */ @@ -900,6 +935,10 @@ RehashCatCache(CatCache *cp) int newnbuckets; int i; + /* try removing old entries before expanding hash */ + if (CatCacheCleanupOldEntries(cp)) + return; + elog(DEBUG1, "rehashing catalog cache id %d for %s; %d tups, %d buckets", cp->id, cp->cc_relname, cp->cc_ntup, cp->cc_nbuckets); @@ -1187,7 +1226,7 @@ SearchCatCacheb(CatCache *cache, Datum v3, Datum v4) { - return SearchCatCacheInternal(cache, cache->cc_nkeys, v1, v2, v3, v4); + return SearchCatCacheInternal(false, cache, cache->cc_nkeys, v1, v2, v3, v4); } @@ -1201,7 +1240,7 @@ static HeapTuple SearchCatCache1b(CatCache *cache, Datum v1) { - return SearchCatCacheInternal(cache, 1, v1, 0, 0, 0); + return SearchCatCacheInternal(false, cache, 1, v1, 0, 0, 0); } @@ -1209,7 +1248,7 @@ static HeapTuple SearchCatCache2b(CatCache *cache, Datum v1, Datum v2) { - return SearchCatCacheInternal(cache, 2, v1, v2, 0, 0); + return SearchCatCacheInternal(false, cache, 2, v1, v2, 0, 0); } @@ -1217,7 +1256,7 @@ static HeapTuple SearchCatCache3b(CatCache *cache, Datum v1, Datum v2, Datum v3) { - return SearchCatCacheInternal(cache, 3, v1, v2, v3, 0); + return SearchCatCacheInternal(false, cache, 3, v1, v2, v3, 0); } @@ -1225,14 +1264,18 @@ static HeapTuple SearchCatCache4b(CatCache *cache, Datum v1, Datum v2, Datum v3, Datum v4) { - return SearchCatCacheInternal(cache, 4, v1, v2, v3, v4); + return SearchCatCacheInternal(false, cache, 4, v1, v2, v3, v4); } /* * Work-horse for SearchCatCache/SearchCatCacheN. + * + * This function expects smarter compiler reduces useless paths by calling with + * fixed parameters. */ static inline HeapTuple -SearchCatCacheInternal(CatCache *cache, +SearchCatCacheInternal(bool do_expire, + CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -1301,6 +1344,20 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* + * Prolong life of this entry. Since we want run as less instructions + * as possible and want the branch be stable for performance reasons, + * we don't give a strict cap on the counter. All numbers above 1 will + * be regarded as 2 in CatCacheCleanupOldEntries(). + */ + if (do_expire) + { + ct->naccess++; + if (unlikely(ct->naccess == 0)) + ct->naccess = 2; + ct->lastaccess = catcacheclock; + } + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1462,6 +1519,150 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * SearchCatCache with entry pruning + * + * These functions works the same way with SearchCatCacheNb() functions except + * that less-used entries are removed following catalog_cache_prune_min_age + * setting. + */ +static HeapTuple +SearchCatCachee(CatCache *cache, + Datum v1, + Datum v2, + Datum v3, + Datum v4) +{ + return SearchCatCacheInternal(true, cache, cache->cc_nkeys, v1, v2, v3, v4); +} + + +/* + * SearchCatCacheN() are SearchCatCache() versions for a specific number of + * arguments. The compiler can inline the body and unroll loops, making them a + * bit faster than SearchCatCache(). + */ + +static HeapTuple +SearchCatCache1e(CatCache *cache, + Datum v1) +{ + return SearchCatCacheInternal(true, cache, 1, v1, 0, 0, 0); +} + + +static HeapTuple +SearchCatCache2e(CatCache *cache, + Datum v1, Datum v2) +{ + return SearchCatCacheInternal(true, cache, 2, v1, v2, 0, 0); +} + + +static HeapTuple +SearchCatCache3e(CatCache *cache, + Datum v1, Datum v2, Datum v3) +{ + return SearchCatCacheInternal(true, cache, 3, v1, v2, v3, 0); +} + + +static HeapTuple +SearchCatCache4e(CatCache *cache, + Datum v1, Datum v2, Datum v3, Datum v4) +{ + return SearchCatCacheInternal(true, cache, 4, v1, v2, v3, v4); +} + +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + long age; + int us; + + /* Return immediately if disabled */ + if (catalog_cache_prune_min_age < 0) + return false; + + /* Don't scan the hash when we know we don't have prunable entries */ + TimestampDifference(cp->cc_oldest_ts, catcacheclock, &age, &us); + if (age < catalog_cache_prune_min_age) + return false; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + /* + * Calculate the duration from the time from the last access + * to the "current" time. catcacheclock is updated + * per-statement basis and additionaly udpated periodically + * during a long running query. + */ + TimestampDifference(ct->lastaccess, catcacheclock, &age, &us); + + if (age > catalog_cache_prune_min_age) + { + /* + * Entries that are not accessed after the last pruning + * are removed in that seconds, and their lives are + * prolonged according to how many times they are accessed + * up to three times of the duration. We don't try shrink + * buckets since pruning effectively caps catcache + * expansion in the long term. + */ + if (ct->naccess > 2) + ct->naccess = 1; + else if (ct->naccess > 0) + ct->naccess--; + else + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't update oldest_ts by removed entry */ + continue; + } + } + } + + /* update oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + + /* * ReleaseCatCache * @@ -1925,6 +2126,8 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->naccess = 0; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); -- 2.18.4 ----Next_Part(Thu_Nov__5_16_26_55_2020_457)---- ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH 4/4] CatCache expiration feature. @ 2020-01-10 06:08 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-01-10 06:08 UTC (permalink / raw) This adds the catcache expiration feature to the catcache mechanism. Current catcache doesn't remove a entry and there's a case where many hash entries occupy large amont of memory , being not accessed ever after. This is a quire serious issue on the cases of long-running sessions. The expiration feature saves the case in exchange of some extent of degradation if it is turned on. --- src/backend/utils/cache/catcache.c | 343 +++++++++++++++++++++++++++-- 1 file changed, 326 insertions(+), 17 deletions(-) diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index 74c893ba4e..35e1a07e57 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -72,10 +72,11 @@ static CatCacheHeader *CacheHdr = NULL; /* Clock for the last accessed time of a catcache entry. */ TimestampTz catcacheclock = 0; -static inline HeapTuple SearchCatCacheInternal(CatCache *cache, - int nkeys, - Datum v1, Datum v2, - Datum v3, Datum v4); +/* basic catcache search functions */ +static inline HeapTuple SearchCatCacheInternalb(CatCache *cache, + int nkeys, + Datum v1, Datum v2, + Datum v3, Datum v4); static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, int nkeys, @@ -93,6 +94,23 @@ static HeapTuple SearchCatCache3b(CatCache *cache, static HeapTuple SearchCatCache4b(CatCache *cache, Datum v1, Datum v2, Datum v3, Datum v4); +/* catcache search functions with expiration feature */ +static inline HeapTuple SearchCatCacheInternale(CatCache *cache, + int nkeys, + Datum v1, Datum v2, + Datum v3, Datum v4); + +static HeapTuple SearchCatCachee(CatCache *cache, + Datum v1, Datum v2, Datum v3, Datum v4); +static HeapTuple SearchCatCache1e(CatCache *cache, Datum v1); +static HeapTuple SearchCatCache2e(CatCache *cache, Datum v1, Datum v2); +static HeapTuple SearchCatCache3e(CatCache *cache, + Datum v1, Datum v2, Datum v3); +static HeapTuple SearchCatCache4e(CatCache *cache, + Datum v1, Datum v2, Datum v3, Datum v4); + +static bool CatCacheCleanupOldEntries(CatCache *cp); + static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); static uint32 CatalogCacheComputeTupleHashValue(CatCache *cache, int nkeys, @@ -125,13 +143,35 @@ static SearchCatCacheFuncsType catcache_base = { SearchCatCache4b }; +static SearchCatCacheFuncsType catcache_expire = { + SearchCatCachee, + SearchCatCache1e, + SearchCatCache2e, + SearchCatCache3e, + SearchCatCache4e +}; + SearchCatCacheFuncsType *SearchCatCacheFuncs = NULL; +/* set catcache function set according to guc variables */ +static void +set_catcache_functions(void) +{ + if (catalog_cache_prune_min_age < 0) + SearchCatCacheFuncs = &catcache_base; + else + SearchCatCacheFuncs = &catcache_expire; +} + + /* GUC assign function */ void assign_catalog_cache_prune_min_age(int newval, void *extra) { catalog_cache_prune_min_age = newval; + + /* choose corresponding function set */ + set_catcache_functions(); } /* @@ -872,7 +912,7 @@ InitCatCache(int id, slist_init(&CacheHdr->ch_caches); CacheHdr->ch_ntup = 0; - SearchCatCacheFuncs = &catcache_base; + set_catcache_functions(); #ifdef CATCACHE_STATS /* set up to dump stats at backend exit */ @@ -938,6 +978,10 @@ RehashCatCache(CatCache *cp) elog(DEBUG1, "rehashing catalog cache id %d for %s; %d tups, %d buckets", cp->id, cp->cc_relname, cp->cc_ntup, cp->cc_nbuckets); + /* try removing old entries before expanding hash */ + if (CatCacheCleanupOldEntries(cp)) + return; + /* Allocate a new, larger, hash table. */ newnbuckets = cp->cc_nbuckets * 2; newbucket = (dlist_head *) MemoryContextAllocZero(CacheMemoryContext, newnbuckets * sizeof(dlist_head)); @@ -1222,7 +1266,7 @@ SearchCatCacheb(CatCache *cache, Datum v3, Datum v4) { - return SearchCatCacheInternal(cache, cache->cc_nkeys, v1, v2, v3, v4); + return SearchCatCacheInternalb(cache, cache->cc_nkeys, v1, v2, v3, v4); } @@ -1236,7 +1280,7 @@ static HeapTuple SearchCatCache1b(CatCache *cache, Datum v1) { - return SearchCatCacheInternal(cache, 1, v1, 0, 0, 0); + return SearchCatCacheInternalb(cache, 1, v1, 0, 0, 0); } @@ -1244,7 +1288,7 @@ static HeapTuple SearchCatCache2b(CatCache *cache, Datum v1, Datum v2) { - return SearchCatCacheInternal(cache, 2, v1, v2, 0, 0); + return SearchCatCacheInternalb(cache, 2, v1, v2, 0, 0); } @@ -1252,7 +1296,7 @@ static HeapTuple SearchCatCache3b(CatCache *cache, Datum v1, Datum v2, Datum v3) { - return SearchCatCacheInternal(cache, 3, v1, v2, v3, 0); + return SearchCatCacheInternalb(cache, 3, v1, v2, v3, 0); } @@ -1260,19 +1304,19 @@ static HeapTuple SearchCatCache4b(CatCache *cache, Datum v1, Datum v2, Datum v3, Datum v4) { - return SearchCatCacheInternal(cache, 4, v1, v2, v3, v4); + return SearchCatCacheInternalb(cache, 4, v1, v2, v3, v4); } /* - * Work-horse for SearchCatCache/SearchCatCacheN. + * Work-horse for SearchCatCacheb/SearchCatCacheNb. */ static inline HeapTuple -SearchCatCacheInternal(CatCache *cache, - int nkeys, - Datum v1, - Datum v2, - Datum v3, - Datum v4) +SearchCatCacheInternalb(CatCache *cache, + int nkeys, + Datum v1, + Datum v2, + Datum v3, + Datum v4) { Datum arguments[CATCACHE_MAXKEYS]; uint32 hashValue; @@ -1497,6 +1541,269 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * SearchCatCache with entry pruning + * + * These functions works the same way with SearchCatCacheNb() functions except + * that less-used entries are removed following catalog_cache_prune_min_age + * setting. + */ +static HeapTuple +SearchCatCachee(CatCache *cache, + Datum v1, + Datum v2, + Datum v3, + Datum v4) +{ + return SearchCatCacheInternale(cache, cache->cc_nkeys, v1, v2, v3, v4); +} + + +/* + * SearchCatCacheN() are SearchCatCache() versions for a specific number of + * arguments. The compiler can inline the body and unroll loops, making them a + * bit faster than SearchCatCache(). + */ + +static HeapTuple +SearchCatCache1e(CatCache *cache, + Datum v1) +{ + return SearchCatCacheInternale(cache, 1, v1, 0, 0, 0); +} + + +static HeapTuple +SearchCatCache2e(CatCache *cache, + Datum v1, Datum v2) +{ + return SearchCatCacheInternale(cache, 2, v1, v2, 0, 0); +} + + +static HeapTuple +SearchCatCache3e(CatCache *cache, + Datum v1, Datum v2, Datum v3) +{ + return SearchCatCacheInternale(cache, 3, v1, v2, v3, 0); +} + + +static HeapTuple +SearchCatCache4e(CatCache *cache, + Datum v1, Datum v2, Datum v3, Datum v4) +{ + return SearchCatCacheInternale(cache, 4, v1, v2, v3, v4); +} + +/* + * Work-horse for SearchCatCachee/SearchCatCacheNe. + */ +static inline HeapTuple +SearchCatCacheInternale(CatCache *cache, + int nkeys, + Datum v1, + Datum v2, + Datum v3, + Datum v4) +{ + Datum arguments[CATCACHE_MAXKEYS]; + uint32 hashValue; + Index hashIndex; + dlist_iter iter; + dlist_head *bucket; + CatCTup *ct; + + /* Make sure we're in an xact, even if this ends up being a cache hit */ + Assert(IsTransactionState()); + + Assert(cache->cc_nkeys == nkeys); + + /* + * one-time startup overhead for each cache + */ + if (unlikely(cache->cc_tupdesc == NULL)) + CatalogCacheInitializeCache(cache); + +#ifdef CATCACHE_STATS + cache->cc_searches++; +#endif + + /* Initialize local parameter array */ + arguments[0] = v1; + arguments[1] = v2; + arguments[2] = v3; + arguments[3] = v4; + + /* + * find the hash bucket in which to look for the tuple + */ + hashValue = CatalogCacheComputeHashValue(cache, nkeys, v1, v2, v3, v4); + hashIndex = HASH_INDEX(hashValue, cache->cc_nbuckets); + + /* + * scan the hash bucket until we find a match or exhaust our tuples + * + * Note: it's okay to use dlist_foreach here, even though we modify the + * dlist within the loop, because we don't continue the loop afterwards. + */ + bucket = &cache->cc_bucket[hashIndex]; + dlist_foreach(iter, bucket) + { + ct = dlist_container(CatCTup, cache_elem, iter.cur); + + if (ct->dead) + continue; /* ignore dead entries */ + + if (ct->hash_value != hashValue) + continue; /* quickly skip entry if wrong hash val */ + + if (!CatalogCacheCompareTuple(cache, nkeys, ct->keys, arguments)) + continue; + + /* + * We found a match in the cache. Move it to the front of the list + * for its hashbucket, in order to speed subsequent searches. (The + * most frequently accessed elements in any hashbucket will tend to be + * near the front of the hashbucket's list.) + */ + dlist_move_head(bucket, &ct->cache_elem); + + /* + * Prolong life of this entry. Since we want run as less instructions + * as possible and want the branch be stable for performance reasons, + * we don't give a strict cap on the counter. All numbers above 1 will + * be regarded as 2 in CatCacheCleanupOldEntries(). + */ + ct->naccess++; + if (unlikely(ct->naccess == 0)) + ct->naccess = 2; + ct->lastaccess = catcacheclock; + + /* + * If it's a positive entry, bump its refcount and return it. If it's + * negative, we can report failure to the caller. + */ + if (!ct->negative) + { + ResourceOwnerEnlargeCatCacheRefs(CurrentResourceOwner); + ct->refcount++; + ResourceOwnerRememberCatCacheRef(CurrentResourceOwner, &ct->tuple); + + CACHE_elog(DEBUG2, "SearchCatCache(%s): found in bucket %d", + cache->cc_relname, hashIndex); + +#ifdef CATCACHE_STATS + cache->cc_hits++; +#endif + + return &ct->tuple; + } + else + { + CACHE_elog(DEBUG2, "SearchCatCache(%s): found neg entry in bucket %d", + cache->cc_relname, hashIndex); + +#ifdef CATCACHE_STATS + cache->cc_neg_hits++; +#endif + + return NULL; + } + } + + return SearchCatCacheMiss(cache, nkeys, hashValue, hashIndex, v1, v2, v3, v4); +} + +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + long age; + int us; + + /* Return immediately if disabled */ + if (catalog_cache_prune_min_age < 0) + return false; + + /* Don't scan the hash when we know we don't have prunable entries */ + TimestampDifference(cp->cc_oldest_ts, catcacheclock, &age, &us); + if (age < catalog_cache_prune_min_age) + return false; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + /* + * Calculate the duration from the time from the last access + * to the "current" time. catcacheclock is updated + * per-statement basis and additionaly udpated periodically + * during a long running query. + */ + TimestampDifference(ct->lastaccess, catcacheclock, &age, &us); + + if (age > catalog_cache_prune_min_age) + { + /* + * Entries that are not accessed after the last pruning + * are removed in that seconds, and their lives are + * prolonged according to how many times they are accessed + * up to three times of the duration. We don't try shrink + * buckets since pruning effectively caps catcache + * expansion in the long term. + */ + if (ct->naccess > 2) + ct->naccess = 1; + else if (ct->naccess > 0) + ct->naccess--; + else + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't update oldest_ts by removed entry */ + continue; + } + } + } + + /* update oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + + /* * ReleaseCatCache * @@ -1960,6 +2267,8 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->naccess = 0; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); -- 2.23.0 ----Next_Part(Tue_Jan_14_12_49_32_2020_834)-- Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="gen_tbl2.pl" #! /usr/bin/perl $collist = ""; foreach $i (0..1000) { $collist .= sprintf(", c%05d int", $i); } $collist = substr($collist, 2); printf "drop schema if exists test cascade;\n"; printf "create schema test;\n"; printf "create table test.p ($collist) partition by list (c00000);\n"; foreach $i (0..2999) { printf "create table test.t%04d partition of test.p for values in (%d);\n", $i, $i; } ----Next_Part(Tue_Jan_14_12_49_32_2020_834)-- Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="run4.sh" #!/bin/bash LOOPS=20 ITERATION=10 BINROOT=/home/horiguti/bin DATADIR=/home/horiguti/data/data_catexpe PREC="numeric(10,2)" /usr/bin/killall postgres /usr/bin/sleep 3 run() { local BINARY=$1 local PGCTL=$2/bin/pg_ctl local PGSQL=$2/bin/postgres local PSQL=$2/bin/psql if [ "$3" != "" ]; then local SETTING1="set catalog_cache_prune_min_age to \"$3\";" local SETTING2="set catalog_cache_prune_min_age to \"$4\";" local SETTING3="set catalog_cache_prune_min_age to \"$5\";" fi # ($PGSQL -D $DATADIR 2>&1 > /dev/null)& ($PGSQL -D $DATADIR 2>&1 > /dev/null | /usr/bin/sed -e 's/^/# /')& /usr/bin/sleep 3 ${PSQL} postgres <<EOF create extension if not exists catcachebench; select catcachebench(0); $SETTING3 select * from generate_series(2, 2) test, LATERAL (select '${BINARY}' as version, count(r)::text || '/${LOOPS}' as n, min(r)::${PREC}, stddev(r)::${PREC} from (select catcachebench(test) as r from generate_series(1, ${LOOPS})) r) r EOF $PGCTL --pgdata=$DATADIR stop 2>&1 > /dev/null | /usr/bin/sed -e 's/^/# /' # oreport > $BINARY_perf.txt } for i in $(seq 0 ${ITERATION}); do run "master" $BINROOT/pgsql_master_o2 "" "" "" run "base" $BINROOT/pgsql_catexp-base "" "" "" run "ind" $BINROOT/pgsql_catexp-ind "" "" "" run "expire-off" $BINROOT/pgsql_catexpe "-1" "-1" "-1" run "expire-on" $BINROOT/pgsql_catexpe "300s" "1s" "0" done ----Next_Part(Tue_Jan_14_12_49_32_2020_834)-- Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="build2.sh" #! /usr/bin/bash BINROOT=/home/horiguti/bin/pgsql_ for i in master_o2 catexp-base catexp-ind catexpe; do rm -r /home/horiguti/bin/pgsql_$i/*; done for i in master_o2 catexp-base catexp-ind catexpe; do ls -l /home/horiguti/bin/pgsql_$i/bin/postgres; done function build () { echo $1 make distclean git checkout $2 git diff master..HEAD > diff_$1.txt ./configure --enable-debug --enable-tap-tests --enable-nls --with-openssl --with-libxml --with-llvm --prefix=${BINROOT}$1 LLVM_CONFIG="/usr/bin/llvm-config" make -sj8 all make install cd contrib/catcachebench make clean make all make install cd ../.. } build "master_o2" "795e92756cd1" build "catexp-base" "b2ebc9b4f1c" build "catexp-ind" "631a04026d" build "catexpe" "025e5e8a98d" for i in master_o2 catexp-base catexp-ind catexpe; do ls -l /home/horiguti/bin/pgsql_$i/bin/postgres; done ----Next_Part(Tue_Jan_14_12_49_32_2020_834)---- ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v4] CatCache expiration feature @ 2020-11-06 08:27 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-06 08:27 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 + src/backend/utils/cache/catcache.c | 125 +++++++++++++++++++++++++++++ src/backend/utils/misc/guc.c | 12 +++ src/include/utils/catcache.h | 20 +++++ 4 files changed, 160 insertions(+) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index af6afcebb1..a246fcc4c0 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index 3613ae5f44..f63224bfd5 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,18 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +TimestampTz catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +84,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +110,12 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + catalog_cache_prune_min_age = newval; +} /* * internal support functions @@ -863,6 +880,10 @@ RehashCatCache(CatCache *cp) int newnbuckets; int i; + /* try removing old entries before expanding hash */ + if (CatCacheCleanupOldEntries(cp)) + return; + elog(DEBUG1, "rehashing catalog cache id %d for %s; %d tups, %d buckets", cp->id, cp->cc_relname, cp->cc_ntup, cp->cc_nbuckets); @@ -1264,6 +1285,20 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* + * Prolong life of this entry. Since we want run as less instructions + * as possible and want the branch be stable for performance reasons, + * we don't give a strict cap on the counter. All numbers above 1 will + * be regarded as 2 in CatCacheCleanupOldEntries(). + */ + if (unlikely(catalog_cache_prune_min_age >= 0)) + { + ct->naccess++; + if (unlikely(ct->naccess == 0)) + ct->naccess = 2; + ct->lastaccess = catcacheclock; + } + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1460,94 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + long age; + int us; + + /* Return immediately if disabled */ + if (likely(catalog_cache_prune_min_age < 0)) + return false; + + /* Don't scan the hash when we know we don't have prunable entries */ + TimestampDifference(cp->cc_oldest_ts, catcacheclock, &age, &us); + if (age < catalog_cache_prune_min_age) + return false; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + /* + * Calculate the duration from the time from the last access + * to the "current" time. catcacheclock is updated + * per-statement basis and additionaly udpated periodically + * during a long running query. + */ + TimestampDifference(ct->lastaccess, catcacheclock, &age, &us); + + if (age > catalog_cache_prune_min_age) + { + /* + * Entries that are not accessed after the last pruning + * are removed in that seconds, and their lives are + * prolonged according to how many times they are accessed + * up to three times of the duration. We don't try shrink + * buckets since pruning effectively caps catcache + * expansion in the long term. + */ + if (ct->naccess > 2) + ct->naccess = 1; + else if (ct->naccess > 0) + ct->naccess--; + else + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't update oldest_ts by removed entry */ + continue; + } + } + } + + /* update oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +2011,8 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->naccess = 0; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index a62d64eaa4..ca897cab2e 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3399,6 +3400,17 @@ static struct config_int ConfigureNamesInt[] = check_huge_page_size, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index f4aa316604..a11736f767 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + TimestampTz cc_oldest_ts; /* timestamp of the oldest tuple in the hash */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,8 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + unsigned int naccess; /* # of access to this entry */ + TimestampTz lastaccess; /* timestamp of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +193,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern TimestampTz catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clodk */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.18.4 ----Next_Part(Fri_Nov__6_17_29_58_2020_781)---- ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v5] CatCache expiration feature @ 2020-11-06 08:27 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-06 08:27 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 + src/backend/utils/cache/catcache.c | 118 +++++++++++++++++++++++++++++ src/backend/utils/misc/guc.c | 12 +++ src/include/utils/catcache.h | 20 +++++ 4 files changed, 153 insertions(+) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index af6afcebb1..a246fcc4c0 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index 3613ae5f44..b457fed7ab 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,18 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +TimestampTz catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +84,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +110,12 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + catalog_cache_prune_min_age = newval; +} /* * internal support functions @@ -863,6 +880,10 @@ RehashCatCache(CatCache *cp) int newnbuckets; int i; + /* try removing old entries before expanding hash */ + if (CatCacheCleanupOldEntries(cp)) + return; + elog(DEBUG1, "rehashing catalog cache id %d for %s; %d tups, %d buckets", cp->id, cp->cc_relname, cp->cc_ntup, cp->cc_nbuckets); @@ -1264,6 +1285,16 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* + * Prolong life of this entry. Since we want run as less instructions + * as possible and want the branch be stable for performance reasons, + * we don't care of wrap-around and possible false-negative for old + * entries. The window is quite narrow and the counter doesn't gets so + * large while expiration is active. + */ + ct->naccess++; + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1456,91 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + long age; + int us; + + /* Return immediately if disabled */ + if (likely(catalog_cache_prune_min_age < 0)) + return false; + + /* Don't scan the hash when we know we don't have prunable entries */ + TimestampDifference(cp->cc_oldest_ts, catcacheclock, &age, &us); + if (age < catalog_cache_prune_min_age) + return false; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + /* + * Calculate the duration from the time from the last access + * to the "current" time. catcacheclock is updated + * per-statement basis and additionaly udpated periodically + * during a long running query. + */ + TimestampDifference(ct->lastaccess, catcacheclock, &age, &us); + + if (age > catalog_cache_prune_min_age) + { + /* + * Entries that are not accessed after the last pruning + * are removed in that seconds, and their lives are + * prolonged according to how many times they are accessed + * up to three times of the duration. We don't try shrink + * buckets since pruning effectively caps catcache + * expansion in the long term. + */ + ct->naccess = Min(2, ct->naccess); + if (--ct->naccess == 0) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't update oldest_ts by removed entry */ + continue; + } + } + } + + /* update oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +2004,8 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->naccess = 1; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index bb34630e8e..95213853aa 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3399,6 +3400,17 @@ static struct config_int ConfigureNamesInt[] = check_huge_page_size, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index f4aa316604..a11736f767 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + TimestampTz cc_oldest_ts; /* timestamp of the oldest tuple in the hash */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,8 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + unsigned int naccess; /* # of access to this entry */ + TimestampTz lastaccess; /* timestamp of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +193,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern TimestampTz catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clodk */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.18.4 ----Next_Part(Mon_Nov__9_18_34_47_2020_166)---- ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v6 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Thu_Jan_14_17_32_27_2021_995)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v6-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v7 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Wed_Jan_27_10_13_08_2021_482)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v7-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v6 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Thu_Jan_14_17_32_27_2021_995)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v6-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v6 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Thu_Jan_14_17_32_27_2021_995)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v6-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v7 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Wed_Jan_27_10_13_08_2021_482)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v7-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v5 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 03c553e7ea..4a2a90ce0c 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index 3613ae5f44..1ebcc7dcd3 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index bb34630e8e..95213853aa 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3399,6 +3400,17 @@ static struct config_int ConfigureNamesInt[] = check_huge_page_size, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index f4aa316604..81587c3fe6 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.18.4 ----Next_Part(Thu_Nov_19_14_25_36_2020_063)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v5-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v6 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Thu_Jan_14_17_32_27_2021_995)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v6-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v7 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Wed_Jan_27_10_13_08_2021_482)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v7-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v7 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Wed_Jan_27_10_13_08_2021_482)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v7-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v6 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Thu_Jan_14_17_32_27_2021_995)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v6-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v7 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Wed_Jan_27_10_13_08_2021_482)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v7-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v6 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Thu_Jan_14_17_32_27_2021_995)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v6-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v7 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Wed_Jan_27_10_13_08_2021_482)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v7-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v6 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Thu_Jan_14_17_32_27_2021_995)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v6-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v7 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Wed_Jan_27_10_13_08_2021_482)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v7-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v6 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Thu_Jan_14_17_32_27_2021_995)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v6-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v7 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Wed_Jan_27_10_13_08_2021_482)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v7-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v6 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Thu_Jan_14_17_32_27_2021_995)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v6-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v7 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Wed_Jan_27_10_13_08_2021_482)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v7-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v6 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Thu_Jan_14_17_32_27_2021_995)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v6-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v7 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Wed_Jan_27_10_13_08_2021_482)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v7-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v6 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Thu_Jan_14_17_32_27_2021_995)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v6-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v7 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Wed_Jan_27_10_13_08_2021_482)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v7-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v6 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Thu_Jan_14_17_32_27_2021_995)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v6-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v7 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Wed_Jan_27_10_13_08_2021_482)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v7-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v6 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Thu_Jan_14_17_32_27_2021_995)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v6-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v7 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Wed_Jan_27_10_13_08_2021_482)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v7-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v6 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Thu_Jan_14_17_32_27_2021_995)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v6-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v7 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Wed_Jan_27_10_13_08_2021_482)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v7-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v6 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Thu_Jan_14_17_32_27_2021_995)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v6-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v7 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Wed_Jan_27_10_13_08_2021_482)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v7-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v6 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Thu_Jan_14_17_32_27_2021_995)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v6-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v7 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Wed_Jan_27_10_13_08_2021_482)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v7-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v7 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Wed_Jan_27_10_13_08_2021_482)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v7-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v6 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Thu_Jan_14_17_32_27_2021_995)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v6-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v7 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Wed_Jan_27_10_13_08_2021_482)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v7-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v6 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Thu_Jan_14_17_32_27_2021_995)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v6-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v7 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Wed_Jan_27_10_13_08_2021_482)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v7-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v6 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Thu_Jan_14_17_32_27_2021_995)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v6-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v7 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Wed_Jan_27_10_13_08_2021_482)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v7-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v6 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Thu_Jan_14_17_32_27_2021_995)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v6-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v7 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Wed_Jan_27_10_13_08_2021_482)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v7-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v6 1/3] CatCache expiration feature @ 2020-11-18 07:54 Kyotaro Horiguchi <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Kyotaro Horiguchi @ 2020-11-18 07:54 UTC (permalink / raw) --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 87 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 19 +++++++ 4 files changed, 120 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..644d92dd9a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,19 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; +uint64 prune_min_age_us; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +uint64 catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +85,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,6 +111,15 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); +/* GUC assign function */ +void +assign_catalog_cache_prune_min_age(int newval, void *extra) +{ + if (newval < 0) + prune_min_age_us = UINT64_MAX; + else + prune_min_age_us = ((uint64) newval) * USECS_PER_SEC; +} /* * internal support functions @@ -1264,6 +1285,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1449,61 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + long oldest_ts = catcacheclock; + uint64 prune_threshold = catcacheclock - prune_min_age_us; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1967,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1979,12 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (catcacheclock - cache->cc_oldest_ts < prune_min_age_us || + !CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca..255e9fa73d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, assign_catalog_cache_prune_min_age, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..291e857e38 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + uint64 cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + uint64 lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,22 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern uint64 catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = (uint64) ts; +} + +extern void assign_catalog_cache_prune_min_age(int newval, void *extra); + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Thu_Jan_14_17_32_27_2021_995)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v6-0002-Remove-dead-flag-from-catcache-tuple.patch" ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v8 1/1] CatCache expiration feature @ 2021-01-27 11:08 Heikki Linnakangas <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Heikki Linnakangas @ 2021-01-27 11:08 UTC (permalink / raw) Author: Kyotaro Horiguchi --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 82 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 17 +++++++ 4 files changed, 112 insertions(+), 2 deletions(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd45..86888d24091 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676e..e29f825687a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,18 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +TimestampTz catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +84,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,7 +110,6 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); - /* * internal support functions */ @@ -1264,6 +1274,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1438,66 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + TimestampTz oldest_ts = catcacheclock; + TimestampTz prune_threshold; + + if (catalog_cache_prune_min_age < 0) + return false; + + prune_threshold = catcacheclock - ((int64) catalog_cache_prune_min_age) * USECS_PER_SEC; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1961,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1973,11 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (!CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca9..f92f0513a6f 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, NULL, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3f..57a15bfec22 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + TimestampTz cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + TimestampTz lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,20 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern TimestampTz catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = ts; +} + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.29.2 --------------38A9F5DCD32945DE1430BC1D-- ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v8 1/1] CatCache expiration feature @ 2021-01-27 11:08 Heikki Linnakangas <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Heikki Linnakangas @ 2021-01-27 11:08 UTC (permalink / raw) Author: Kyotaro Horiguchi --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 82 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 17 +++++++ 4 files changed, 112 insertions(+), 2 deletions(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd45..86888d24091 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676e..e29f825687a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,18 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +TimestampTz catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +84,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,7 +110,6 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); - /* * internal support functions */ @@ -1264,6 +1274,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1438,66 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + TimestampTz oldest_ts = catcacheclock; + TimestampTz prune_threshold; + + if (catalog_cache_prune_min_age < 0) + return false; + + prune_threshold = catcacheclock - ((int64) catalog_cache_prune_min_age) * USECS_PER_SEC; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1961,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1973,11 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (!CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca9..f92f0513a6f 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, NULL, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3f..57a15bfec22 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + TimestampTz cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + TimestampTz lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,20 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern TimestampTz catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = ts; +} + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.29.2 --------------38A9F5DCD32945DE1430BC1D-- ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v8 1/1] CatCache expiration feature @ 2021-01-27 11:08 Heikki Linnakangas <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Heikki Linnakangas @ 2021-01-27 11:08 UTC (permalink / raw) Author: Kyotaro Horiguchi --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 82 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 17 +++++++ 4 files changed, 112 insertions(+), 2 deletions(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd45..86888d24091 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676e..e29f825687a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,18 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +TimestampTz catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +84,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,7 +110,6 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); - /* * internal support functions */ @@ -1264,6 +1274,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1438,66 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + TimestampTz oldest_ts = catcacheclock; + TimestampTz prune_threshold; + + if (catalog_cache_prune_min_age < 0) + return false; + + prune_threshold = catcacheclock - ((int64) catalog_cache_prune_min_age) * USECS_PER_SEC; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1961,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1973,11 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (!CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca9..f92f0513a6f 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, NULL, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3f..57a15bfec22 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + TimestampTz cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + TimestampTz lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,20 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern TimestampTz catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = ts; +} + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.29.2 --------------38A9F5DCD32945DE1430BC1D-- ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v8 1/1] CatCache expiration feature @ 2021-01-27 11:08 Heikki Linnakangas <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Heikki Linnakangas @ 2021-01-27 11:08 UTC (permalink / raw) Author: Kyotaro Horiguchi --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 82 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 17 +++++++ 4 files changed, 112 insertions(+), 2 deletions(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd45..86888d24091 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676e..e29f825687a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,18 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +TimestampTz catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +84,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,7 +110,6 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); - /* * internal support functions */ @@ -1264,6 +1274,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1438,66 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + TimestampTz oldest_ts = catcacheclock; + TimestampTz prune_threshold; + + if (catalog_cache_prune_min_age < 0) + return false; + + prune_threshold = catcacheclock - ((int64) catalog_cache_prune_min_age) * USECS_PER_SEC; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1961,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1973,11 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (!CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca9..f92f0513a6f 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, NULL, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3f..57a15bfec22 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + TimestampTz cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + TimestampTz lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,20 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern TimestampTz catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = ts; +} + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.29.2 --------------38A9F5DCD32945DE1430BC1D-- ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v8 1/1] CatCache expiration feature @ 2021-01-27 11:08 Heikki Linnakangas <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Heikki Linnakangas @ 2021-01-27 11:08 UTC (permalink / raw) Author: Kyotaro Horiguchi --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 82 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 17 +++++++ 4 files changed, 112 insertions(+), 2 deletions(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd45..86888d24091 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676e..e29f825687a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,18 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +TimestampTz catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +84,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,7 +110,6 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); - /* * internal support functions */ @@ -1264,6 +1274,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1438,66 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + TimestampTz oldest_ts = catcacheclock; + TimestampTz prune_threshold; + + if (catalog_cache_prune_min_age < 0) + return false; + + prune_threshold = catcacheclock - ((int64) catalog_cache_prune_min_age) * USECS_PER_SEC; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1961,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1973,11 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (!CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca9..f92f0513a6f 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, NULL, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3f..57a15bfec22 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + TimestampTz cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + TimestampTz lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,20 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern TimestampTz catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = ts; +} + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.29.2 --------------38A9F5DCD32945DE1430BC1D-- ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v8 1/1] CatCache expiration feature @ 2021-01-27 11:08 Heikki Linnakangas <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Heikki Linnakangas @ 2021-01-27 11:08 UTC (permalink / raw) Author: Kyotaro Horiguchi --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 82 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 17 +++++++ 4 files changed, 112 insertions(+), 2 deletions(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd45..86888d24091 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676e..e29f825687a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,18 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +TimestampTz catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +84,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,7 +110,6 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); - /* * internal support functions */ @@ -1264,6 +1274,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1438,66 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + TimestampTz oldest_ts = catcacheclock; + TimestampTz prune_threshold; + + if (catalog_cache_prune_min_age < 0) + return false; + + prune_threshold = catcacheclock - ((int64) catalog_cache_prune_min_age) * USECS_PER_SEC; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1961,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1973,11 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (!CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca9..f92f0513a6f 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, NULL, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3f..57a15bfec22 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + TimestampTz cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + TimestampTz lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,20 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern TimestampTz catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = ts; +} + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.29.2 --------------38A9F5DCD32945DE1430BC1D-- ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v8 1/1] CatCache expiration feature @ 2021-01-27 11:08 Heikki Linnakangas <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Heikki Linnakangas @ 2021-01-27 11:08 UTC (permalink / raw) Author: Kyotaro Horiguchi --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 82 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 17 +++++++ 4 files changed, 112 insertions(+), 2 deletions(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd45..86888d24091 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676e..e29f825687a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,18 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +TimestampTz catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +84,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,7 +110,6 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); - /* * internal support functions */ @@ -1264,6 +1274,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1438,66 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + TimestampTz oldest_ts = catcacheclock; + TimestampTz prune_threshold; + + if (catalog_cache_prune_min_age < 0) + return false; + + prune_threshold = catcacheclock - ((int64) catalog_cache_prune_min_age) * USECS_PER_SEC; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1961,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1973,11 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (!CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca9..f92f0513a6f 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, NULL, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3f..57a15bfec22 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + TimestampTz cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + TimestampTz lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,20 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern TimestampTz catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = ts; +} + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.29.2 --------------38A9F5DCD32945DE1430BC1D-- ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v8 1/1] CatCache expiration feature @ 2021-01-27 11:08 Heikki Linnakangas <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Heikki Linnakangas @ 2021-01-27 11:08 UTC (permalink / raw) Author: Kyotaro Horiguchi --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 82 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 17 +++++++ 4 files changed, 112 insertions(+), 2 deletions(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd45..86888d24091 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676e..e29f825687a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,18 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +TimestampTz catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +84,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,7 +110,6 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); - /* * internal support functions */ @@ -1264,6 +1274,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1438,66 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + TimestampTz oldest_ts = catcacheclock; + TimestampTz prune_threshold; + + if (catalog_cache_prune_min_age < 0) + return false; + + prune_threshold = catcacheclock - ((int64) catalog_cache_prune_min_age) * USECS_PER_SEC; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1961,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1973,11 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (!CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca9..f92f0513a6f 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, NULL, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3f..57a15bfec22 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + TimestampTz cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + TimestampTz lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,20 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern TimestampTz catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = ts; +} + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.29.2 --------------38A9F5DCD32945DE1430BC1D-- ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v8 1/1] CatCache expiration feature @ 2021-01-27 11:08 Heikki Linnakangas <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Heikki Linnakangas @ 2021-01-27 11:08 UTC (permalink / raw) Author: Kyotaro Horiguchi --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 82 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 17 +++++++ 4 files changed, 112 insertions(+), 2 deletions(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd45..86888d24091 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676e..e29f825687a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,18 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +TimestampTz catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +84,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,7 +110,6 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); - /* * internal support functions */ @@ -1264,6 +1274,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1438,66 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + TimestampTz oldest_ts = catcacheclock; + TimestampTz prune_threshold; + + if (catalog_cache_prune_min_age < 0) + return false; + + prune_threshold = catcacheclock - ((int64) catalog_cache_prune_min_age) * USECS_PER_SEC; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1961,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1973,11 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (!CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca9..f92f0513a6f 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, NULL, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3f..57a15bfec22 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + TimestampTz cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + TimestampTz lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,20 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern TimestampTz catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = ts; +} + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.29.2 --------------38A9F5DCD32945DE1430BC1D-- ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v8 1/1] CatCache expiration feature @ 2021-01-27 11:08 Heikki Linnakangas <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Heikki Linnakangas @ 2021-01-27 11:08 UTC (permalink / raw) Author: Kyotaro Horiguchi --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 82 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 17 +++++++ 4 files changed, 112 insertions(+), 2 deletions(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd45..86888d24091 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676e..e29f825687a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,18 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +TimestampTz catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +84,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,7 +110,6 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); - /* * internal support functions */ @@ -1264,6 +1274,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1438,66 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + TimestampTz oldest_ts = catcacheclock; + TimestampTz prune_threshold; + + if (catalog_cache_prune_min_age < 0) + return false; + + prune_threshold = catcacheclock - ((int64) catalog_cache_prune_min_age) * USECS_PER_SEC; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1961,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1973,11 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (!CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca9..f92f0513a6f 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, NULL, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3f..57a15bfec22 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + TimestampTz cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + TimestampTz lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,20 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern TimestampTz catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = ts; +} + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.29.2 --------------38A9F5DCD32945DE1430BC1D-- ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v8 1/1] CatCache expiration feature @ 2021-01-27 11:08 Heikki Linnakangas <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Heikki Linnakangas @ 2021-01-27 11:08 UTC (permalink / raw) Author: Kyotaro Horiguchi --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 82 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 17 +++++++ 4 files changed, 112 insertions(+), 2 deletions(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd45..86888d24091 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676e..e29f825687a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,18 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +TimestampTz catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +84,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,7 +110,6 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); - /* * internal support functions */ @@ -1264,6 +1274,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1438,66 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + TimestampTz oldest_ts = catcacheclock; + TimestampTz prune_threshold; + + if (catalog_cache_prune_min_age < 0) + return false; + + prune_threshold = catcacheclock - ((int64) catalog_cache_prune_min_age) * USECS_PER_SEC; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1961,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1973,11 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (!CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca9..f92f0513a6f 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, NULL, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3f..57a15bfec22 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + TimestampTz cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + TimestampTz lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,20 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern TimestampTz catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = ts; +} + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.29.2 --------------38A9F5DCD32945DE1430BC1D-- ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v8 1/1] CatCache expiration feature @ 2021-01-27 11:08 Heikki Linnakangas <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Heikki Linnakangas @ 2021-01-27 11:08 UTC (permalink / raw) Author: Kyotaro Horiguchi --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 82 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 17 +++++++ 4 files changed, 112 insertions(+), 2 deletions(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd45..86888d24091 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676e..e29f825687a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,18 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +TimestampTz catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +84,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,7 +110,6 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); - /* * internal support functions */ @@ -1264,6 +1274,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1438,66 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + TimestampTz oldest_ts = catcacheclock; + TimestampTz prune_threshold; + + if (catalog_cache_prune_min_age < 0) + return false; + + prune_threshold = catcacheclock - ((int64) catalog_cache_prune_min_age) * USECS_PER_SEC; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1961,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1973,11 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (!CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca9..f92f0513a6f 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, NULL, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3f..57a15bfec22 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + TimestampTz cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + TimestampTz lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,20 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern TimestampTz catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = ts; +} + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.29.2 --------------38A9F5DCD32945DE1430BC1D-- ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v8 1/1] CatCache expiration feature @ 2021-01-27 11:08 Heikki Linnakangas <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Heikki Linnakangas @ 2021-01-27 11:08 UTC (permalink / raw) Author: Kyotaro Horiguchi --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 82 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 17 +++++++ 4 files changed, 112 insertions(+), 2 deletions(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd45..86888d24091 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676e..e29f825687a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,18 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +TimestampTz catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +84,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,7 +110,6 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); - /* * internal support functions */ @@ -1264,6 +1274,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1438,66 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + TimestampTz oldest_ts = catcacheclock; + TimestampTz prune_threshold; + + if (catalog_cache_prune_min_age < 0) + return false; + + prune_threshold = catcacheclock - ((int64) catalog_cache_prune_min_age) * USECS_PER_SEC; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1961,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1973,11 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (!CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca9..f92f0513a6f 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, NULL, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3f..57a15bfec22 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + TimestampTz cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + TimestampTz lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,20 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern TimestampTz catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = ts; +} + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.29.2 --------------38A9F5DCD32945DE1430BC1D-- ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v8 1/1] CatCache expiration feature @ 2021-01-27 11:08 Heikki Linnakangas <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Heikki Linnakangas @ 2021-01-27 11:08 UTC (permalink / raw) Author: Kyotaro Horiguchi --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 82 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 17 +++++++ 4 files changed, 112 insertions(+), 2 deletions(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd45..86888d24091 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676e..e29f825687a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,18 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +TimestampTz catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +84,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,7 +110,6 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); - /* * internal support functions */ @@ -1264,6 +1274,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1438,66 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + TimestampTz oldest_ts = catcacheclock; + TimestampTz prune_threshold; + + if (catalog_cache_prune_min_age < 0) + return false; + + prune_threshold = catcacheclock - ((int64) catalog_cache_prune_min_age) * USECS_PER_SEC; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1961,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1973,11 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (!CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca9..f92f0513a6f 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, NULL, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3f..57a15bfec22 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + TimestampTz cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + TimestampTz lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,20 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern TimestampTz catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = ts; +} + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.29.2 --------------38A9F5DCD32945DE1430BC1D-- ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v8 1/1] CatCache expiration feature @ 2021-01-27 11:08 Heikki Linnakangas <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Heikki Linnakangas @ 2021-01-27 11:08 UTC (permalink / raw) Author: Kyotaro Horiguchi --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 82 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 17 +++++++ 4 files changed, 112 insertions(+), 2 deletions(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd45..86888d24091 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676e..e29f825687a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,18 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +TimestampTz catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +84,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,7 +110,6 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); - /* * internal support functions */ @@ -1264,6 +1274,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1438,66 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + TimestampTz oldest_ts = catcacheclock; + TimestampTz prune_threshold; + + if (catalog_cache_prune_min_age < 0) + return false; + + prune_threshold = catcacheclock - ((int64) catalog_cache_prune_min_age) * USECS_PER_SEC; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1961,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1973,11 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (!CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca9..f92f0513a6f 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, NULL, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3f..57a15bfec22 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + TimestampTz cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + TimestampTz lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,20 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern TimestampTz catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = ts; +} + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.29.2 --------------38A9F5DCD32945DE1430BC1D-- ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v8 1/1] CatCache expiration feature @ 2021-01-27 11:08 Heikki Linnakangas <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Heikki Linnakangas @ 2021-01-27 11:08 UTC (permalink / raw) Author: Kyotaro Horiguchi --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 82 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 17 +++++++ 4 files changed, 112 insertions(+), 2 deletions(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd45..86888d24091 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676e..e29f825687a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,18 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +TimestampTz catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +84,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,7 +110,6 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); - /* * internal support functions */ @@ -1264,6 +1274,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1438,66 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + TimestampTz oldest_ts = catcacheclock; + TimestampTz prune_threshold; + + if (catalog_cache_prune_min_age < 0) + return false; + + prune_threshold = catcacheclock - ((int64) catalog_cache_prune_min_age) * USECS_PER_SEC; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1961,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1973,11 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (!CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca9..f92f0513a6f 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, NULL, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3f..57a15bfec22 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + TimestampTz cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + TimestampTz lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,20 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern TimestampTz catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = ts; +} + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.29.2 --------------38A9F5DCD32945DE1430BC1D-- ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v9] CatCache expiration feature @ 2021-01-27 11:08 Heikki Linnakangas <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Heikki Linnakangas @ 2021-01-27 11:08 UTC (permalink / raw) Author: Kyotaro Horiguchi --- doc/src/sgml/config.sgml | 20 +++++++ src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 85 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 17 ++++++ 5 files changed, 136 insertions(+), 1 deletion(-) diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml index f1037df5a9..14be8061ce 100644 --- a/doc/src/sgml/config.sgml +++ b/doc/src/sgml/config.sgml @@ -1960,6 +1960,26 @@ include_dir 'conf.d' </listitem> </varlistentry> + <varlistentry id="guc-catalog-cache-prune-min-age" xreflabel="catalog_cache_prune_min_age"> + <term><varname>catalog_cache_prune_min_age</varname> (<type>integer</type>) + <indexterm> + <primary><varname>catalog_cache_prune_min_age</varname> configuration parameter</primary> + </indexterm> + </term> + <listitem> + <para> + Setting <varname>catalog_cache_prune_min_age</varname> allows catalog + cache entries older than this seconds removed. A value + of <literal>-1</literal> disables this feature, effectively setting + the value to infinity. The default is 600 seconds. You can reduce + this value to reduce the amount of memory used by the catalog cache in + exchange of possible performance degradation or increase it to gain in + performance of intermittently executed queries in exchange of the + possible increase of memory usage. + </para> + </listitem> + </varlistentry> + </variablelist> </sect2> diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd4..86888d2409 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676..3e24a81992 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,18 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that are the candidates + * for evictetion in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of catcache entry. */ +TimestampTz catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +84,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -833,6 +844,7 @@ InitCatCache(int id, cp->cc_nkeys = nkeys; for (i = 0; i < nkeys; ++i) cp->cc_keyno[i] = key[i]; + cp->cc_oldest_ts = catcacheclock; /* * new cache is initialized as far as we can go for now. print some @@ -1264,6 +1276,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1440,69 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Removes entries that has been left alone for a certain period to prevent + * catcache bloat. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + TimestampTz oldest_ts = catcacheclock; + TimestampTz prune_threshold; + + if (catalog_cache_prune_min_age < 0) + return false; + + /* entries older than this time would be removed */ + prune_threshold = catcacheclock - + ((int64) catalog_cache_prune_min_age) * USECS_PER_SEC; + + /* return if we know we have no entry to remove */ + if (cp->cc_oldest_ts > prune_threshold) + return false; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess <= prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1966,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1978,11 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (!CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index eafdb1118e..6a1e52911a 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are unused more than this seconds are to be removed."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + 600, -1, INT_MAX, + NULL, NULL, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3..786df7aeda 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + TimestampTz cc_oldest_ts; /* timestamp of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + TimestampTz lastaccess; /* timestamp of the last use */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,20 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern TimestampTz catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = ts; +} + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.27.0 ----Next_Part(Thu_Jan_28_16_50_44_2021_768)---- ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v8 1/1] CatCache expiration feature @ 2021-01-27 11:08 Heikki Linnakangas <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Heikki Linnakangas @ 2021-01-27 11:08 UTC (permalink / raw) Author: Kyotaro Horiguchi --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 82 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 17 +++++++ 4 files changed, 112 insertions(+), 2 deletions(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd45..86888d24091 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676e..e29f825687a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,18 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +TimestampTz catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +84,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,7 +110,6 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); - /* * internal support functions */ @@ -1264,6 +1274,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1438,66 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + TimestampTz oldest_ts = catcacheclock; + TimestampTz prune_threshold; + + if (catalog_cache_prune_min_age < 0) + return false; + + prune_threshold = catcacheclock - ((int64) catalog_cache_prune_min_age) * USECS_PER_SEC; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1961,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1973,11 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (!CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca9..f92f0513a6f 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, NULL, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3f..57a15bfec22 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + TimestampTz cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + TimestampTz lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,20 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern TimestampTz catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = ts; +} + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.29.2 --------------38A9F5DCD32945DE1430BC1D-- ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v8 1/1] CatCache expiration feature @ 2021-01-27 11:08 Heikki Linnakangas <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Heikki Linnakangas @ 2021-01-27 11:08 UTC (permalink / raw) Author: Kyotaro Horiguchi --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 82 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 17 +++++++ 4 files changed, 112 insertions(+), 2 deletions(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd45..86888d24091 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676e..e29f825687a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,18 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +TimestampTz catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +84,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,7 +110,6 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); - /* * internal support functions */ @@ -1264,6 +1274,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1438,66 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + TimestampTz oldest_ts = catcacheclock; + TimestampTz prune_threshold; + + if (catalog_cache_prune_min_age < 0) + return false; + + prune_threshold = catcacheclock - ((int64) catalog_cache_prune_min_age) * USECS_PER_SEC; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1961,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1973,11 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (!CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca9..f92f0513a6f 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, NULL, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3f..57a15bfec22 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + TimestampTz cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + TimestampTz lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,20 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern TimestampTz catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = ts; +} + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.29.2 --------------38A9F5DCD32945DE1430BC1D-- ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v8 1/1] CatCache expiration feature @ 2021-01-27 11:08 Heikki Linnakangas <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Heikki Linnakangas @ 2021-01-27 11:08 UTC (permalink / raw) Author: Kyotaro Horiguchi --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 82 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 17 +++++++ 4 files changed, 112 insertions(+), 2 deletions(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd45..86888d24091 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676e..e29f825687a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,18 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +TimestampTz catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +84,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,7 +110,6 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); - /* * internal support functions */ @@ -1264,6 +1274,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1438,66 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + TimestampTz oldest_ts = catcacheclock; + TimestampTz prune_threshold; + + if (catalog_cache_prune_min_age < 0) + return false; + + prune_threshold = catcacheclock - ((int64) catalog_cache_prune_min_age) * USECS_PER_SEC; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1961,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1973,11 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (!CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca9..f92f0513a6f 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, NULL, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3f..57a15bfec22 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + TimestampTz cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + TimestampTz lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,20 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern TimestampTz catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = ts; +} + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.29.2 --------------38A9F5DCD32945DE1430BC1D-- ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v8 1/1] CatCache expiration feature @ 2021-01-27 11:08 Heikki Linnakangas <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Heikki Linnakangas @ 2021-01-27 11:08 UTC (permalink / raw) Author: Kyotaro Horiguchi --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 82 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 17 +++++++ 4 files changed, 112 insertions(+), 2 deletions(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd45..86888d24091 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676e..e29f825687a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,18 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +TimestampTz catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +84,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,7 +110,6 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); - /* * internal support functions */ @@ -1264,6 +1274,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1438,66 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + TimestampTz oldest_ts = catcacheclock; + TimestampTz prune_threshold; + + if (catalog_cache_prune_min_age < 0) + return false; + + prune_threshold = catcacheclock - ((int64) catalog_cache_prune_min_age) * USECS_PER_SEC; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1961,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1973,11 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (!CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca9..f92f0513a6f 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, NULL, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3f..57a15bfec22 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + TimestampTz cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + TimestampTz lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,20 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern TimestampTz catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = ts; +} + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.29.2 --------------38A9F5DCD32945DE1430BC1D-- ^ permalink raw reply [nested|flat] 72+ messages in thread
* [PATCH v8 1/1] CatCache expiration feature @ 2021-01-27 11:08 Heikki Linnakangas <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Heikki Linnakangas @ 2021-01-27 11:08 UTC (permalink / raw) Author: Kyotaro Horiguchi --- src/backend/access/transam/xact.c | 3 ++ src/backend/utils/cache/catcache.c | 82 +++++++++++++++++++++++++++++- src/backend/utils/misc/guc.c | 12 +++++ src/include/utils/catcache.h | 17 +++++++ 4 files changed, 112 insertions(+), 2 deletions(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index a2068e3fd45..86888d24091 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1086,6 +1086,9 @@ static void AtStart_Cache(void) { AcceptInvalidationMessages(); + + if (xactStartTimestamp != 0) + SetCatCacheClock(xactStartTimestamp); } /* diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index fa2b49c676e..e29f825687a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -38,6 +38,7 @@ #include "utils/rel.h" #include "utils/resowner_private.h" #include "utils/syscache.h" +#include "utils/timestamp.h" /* #define CACHEDEBUG */ /* turns DEBUG elogs on */ @@ -60,9 +61,18 @@ #define CACHE_elog(...) #endif +/* + * GUC variable to define the minimum age of entries that will be considered + * to be evicted in seconds. -1 to disable the feature. + */ +int catalog_cache_prune_min_age = -1; + /* Cache management header --- pointer is NULL until created */ static CatCacheHeader *CacheHdr = NULL; +/* Clock for the last accessed time of a catcache entry. */ +TimestampTz catcacheclock = 0; + static inline HeapTuple SearchCatCacheInternal(CatCache *cache, int nkeys, Datum v1, Datum v2, @@ -74,6 +84,7 @@ static pg_noinline HeapTuple SearchCatCacheMiss(CatCache *cache, Index hashIndex, Datum v1, Datum v2, Datum v3, Datum v4); +static bool CatCacheCleanupOldEntries(CatCache *cp); static uint32 CatalogCacheComputeHashValue(CatCache *cache, int nkeys, Datum v1, Datum v2, Datum v3, Datum v4); @@ -99,7 +110,6 @@ static void CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, static void CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *srckeys, Datum *dstkeys); - /* * internal support functions */ @@ -1264,6 +1274,9 @@ SearchCatCacheInternal(CatCache *cache, */ dlist_move_head(bucket, &ct->cache_elem); + /* Record the last access timestamp */ + ct->lastaccess = catcacheclock; + /* * If it's a positive entry, bump its refcount and return it. If it's * negative, we can report failure to the caller. @@ -1425,6 +1438,66 @@ SearchCatCacheMiss(CatCache *cache, return &ct->tuple; } +/* + * CatCacheCleanupOldEntries - Remove infrequently-used entries + * + * Catcache entries happen to be left unused for a long time for several + * reasons. Remove such entries to prevent catcache from bloating. It is based + * on the similar algorithm with buffer eviction. Entries that are accessed + * several times in a certain period live longer than those that have had less + * access in the same duration. + */ +static bool +CatCacheCleanupOldEntries(CatCache *cp) +{ + int nremoved = 0; + int i; + TimestampTz oldest_ts = catcacheclock; + TimestampTz prune_threshold; + + if (catalog_cache_prune_min_age < 0) + return false; + + prune_threshold = catcacheclock - ((int64) catalog_cache_prune_min_age) * USECS_PER_SEC; + + /* Scan over the whole hash to find entries to remove */ + for (i = 0 ; i < cp->cc_nbuckets ; i++) + { + dlist_mutable_iter iter; + + dlist_foreach_modify(iter, &cp->cc_bucket[i]) + { + CatCTup *ct = dlist_container(CatCTup, cache_elem, iter.cur); + + /* Don't remove referenced entries */ + if (ct->refcount == 0 && + (ct->c_list == NULL || ct->c_list->refcount == 0)) + { + if (ct->lastaccess < prune_threshold) + { + CatCacheRemoveCTup(cp, ct); + nremoved++; + + /* don't let the removed entry update oldest_ts */ + continue; + } + } + + /* update the oldest timestamp if the entry remains alive */ + if (ct->lastaccess < oldest_ts) + oldest_ts = ct->lastaccess; + } + } + + cp->cc_oldest_ts = oldest_ts; + + if (nremoved > 0) + elog(DEBUG1, "pruning catalog cache id=%d for %s: removed %d / %d", + cp->id, cp->cc_relname, nremoved, cp->cc_ntup + nremoved); + + return nremoved > 0; +} + /* * ReleaseCatCache * @@ -1888,6 +1961,7 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, ct->dead = false; ct->negative = negative; ct->hash_value = hashValue; + ct->lastaccess = catcacheclock; dlist_push_head(&cache->cc_bucket[hashIndex], &ct->cache_elem); @@ -1899,7 +1973,11 @@ CatalogCacheCreateEntry(CatCache *cache, HeapTuple ntp, Datum *arguments, * arbitrarily, we enlarge when fill factor > 2. */ if (cache->cc_ntup > cache->cc_nbuckets * 2) - RehashCatCache(cache); + { + /* try removing old entries before expanding hash */ + if (!CatCacheCleanupOldEntries(cache)) + RehashCatCache(cache); + } return ct; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 17579eeaca9..f92f0513a6f 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -88,6 +88,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/bytea.h" +#include "utils/catcache.h" #include "utils/float.h" #include "utils/guc_tables.h" #include "utils/memutils.h" @@ -3445,6 +3446,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"catalog_cache_prune_min_age", PGC_USERSET, RESOURCES_MEM, + gettext_noop("System catalog cache entries that are living unused more than this seconds are considered for removal."), + gettext_noop("The value of -1 turns off pruning."), + GUC_UNIT_S + }, + &catalog_cache_prune_min_age, + -1, -1, INT_MAX, + NULL, NULL, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index ddc2762eb3f..57a15bfec22 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -22,6 +22,7 @@ #include "access/htup.h" #include "access/skey.h" +#include "datatype/timestamp.h" #include "lib/ilist.h" #include "utils/relcache.h" @@ -61,6 +62,7 @@ typedef struct catcache slist_node cc_next; /* list link */ ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for heap * scans */ + TimestampTz cc_oldest_ts; /* timestamp (us) of the oldest tuple */ /* * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS @@ -119,6 +121,7 @@ typedef struct catctup bool dead; /* dead but not yet removed? */ bool negative; /* negative cache entry? */ HeapTupleData tuple; /* tuple management header */ + TimestampTz lastaccess; /* timestamp in us of the last usage */ /* * The tuple may also be a member of at most one CatCList. (If a single @@ -189,6 +192,20 @@ typedef struct catcacheheader /* this extern duplicates utils/memutils.h... */ extern PGDLLIMPORT MemoryContext CacheMemoryContext; + +/* for guc.c, not PGDLLPMPORT'ed */ +extern int catalog_cache_prune_min_age; + +/* source clock for access timestamp of catcache entries */ +extern TimestampTz catcacheclock; + +/* SetCatCacheClock - set catcache timestamp source clock */ +static inline void +SetCatCacheClock(TimestampTz ts) +{ + catcacheclock = ts; +} + extern void CreateCacheMemoryContext(void); extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, -- 2.29.2 --------------38A9F5DCD32945DE1430BC1D-- ^ permalink raw reply [nested|flat] 72+ messages in thread
* Re: Add Pipelining support in psql @ 2024-11-28 09:22 Anthonin Bonnefoy <[email protected]> 0 siblings, 0 replies; 72+ messages in thread From: Anthonin Bonnefoy @ 2024-11-28 09:22 UTC (permalink / raw) To: Jelte Fennema-Nio <[email protected]>; +Cc: Michael Paquier <[email protected]>; pgsql-hackers On Wed, Nov 27, 2024 at 11:46 AM Kirill Reshke <[email protected]> wrote: > I'm very doubtful about the \syncpipeline . Maybe we should instead > support \sync meta-command in psql? This will be a useful contribution > itself. \syncpipeline is useful to cover regression tests involving implicit transaction blocks within a pipeline where a sync acts as an implicit COMMIT. What would be the use of sending a \sync outside of a pipeline? All extended queries meta-commands sent by psql already send a sync if you're not in a pipeline, so the only use of a \sync meta-command would be to send a single sync (which could be achieved with \startpipeline followed by a \endpipeline). On Wed, Nov 27, 2024 at 1:54 PM Jelte Fennema-Nio <[email protected]> wrote: > This behaviour is expected, it also happens if you send "SELECT 1" > instead of "begin" in the parse message: > db1=# \startpipeline > db1=# SELECT 1 \parse p1 > db1=*# > > The reason this happens is that the first command in a pipeline sent > to the server opens an implicit transaction. See the "implicit COMMIT" > wording here[1], or look at this code in exec_parse_message: I don't think that's the case here. Nothing was sent to the server so there's no active transaction yet. From prompt.c, psql will show a '*' when PQtransactionStatus is either PQTRANS_ACTIVE or PQTRANS_INTRANS. Looking at the state of the PGConn, after a \startpipeline, we have: db->xactStatus: (PGTransactionStatusType) PQTRANS_IDLE db->asyncStatus: (PGAsyncStatusType) PGASYNC_IDLE db->pipelineStatus: (PGpipelineStatus) PQ_PIPELINE_ON After the first command is sent to the pipeline: db->asyncStatus: (PGAsyncStatusType) PGASYNC_BUSY db->xactStatus: (PGTransactionStatusType) PQTRANS_IDLE db->pipelineStatus: (PGpipelineStatus) PQ_PIPELINE_ON The xactStatus is idle, however, since asyncStatus reports busy, we fall in the "if (conn->asyncStatus != PGASYNC_IDLE) return PQTRANS_ACTIVE;" and psql display '*' in the prompt. This might be a bit misleading since there's no ongoing transaction block on the server and maybe it's worth having a new state? I've updated the patch to display a tentative '|' when there's an ongoing pipeline. On the other hand, a pipeline will start an implicit transaction block even without BEGIN so leaving the '*' may be a good way to reflect that? On Wed, Nov 27, 2024 at 1:45 PM Jelte Fennema-Nio <[email protected]> wrote: > I played around quickly with this patch and it works quite well. A few > things that would be nice improvements I think. Feel free to change > the command names: > 1. Add a \flush command that calls PQflush > 2. Add a \flushrequest command that calls PQsendFlushRequest > 3. Add a \getresult command so you can get a result from a query > without having to close the pipeline > > To be clear, not having those additional commands isn't a blocker for > this patch imho, but I'd definitely miss them if they weren't there > when I would be using it. I will need a bit of time to check those and how they can be included in the regression tests. Attachments: [application/octet-stream] v02-0001-Add-pipelining-support-in-psql.patch (32.7K, ../../CAO6_XqrseE1UGxMEHu3CARdn5HW_C4rqR3Xy=Vg2sfHjPRa1og@mail.gmail.com/2-v02-0001-Add-pipelining-support-in-psql.patch) download | inline diff: From 0831ee6dff883fe8b9f41cecdc45cc43345887a7 Mon Sep 17 00:00:00 2001 From: Anthonin Bonnefoy <[email protected]> Date: Tue, 5 Nov 2024 10:26:54 +0100 Subject: Add pipelining support in psql With \bind, \parse, \bind_named and \close, it is possible to issue queries from psql using the extended protocol. However, it wasn't possible to send those queries using pipelining and the only way to test pipelined queries was through pgbench's tap tests. This patch adds additional psql meta-commands to support pipelining: \startpipeline, \endpipeline and \syncpipeline, mirroring the existing meta-commands in pgbench. \startpipeline starts a new pipeline. All extended queries will be queued until the end of the pipeline is reached. \endpipeline ends an ongoing pipeline. All queued commands will be sent to the server and all responses will be processed by the psql. \syncpipeline queue a synchronisation point without flushing the commands to the server Those meta-commands will allow to test pipeline behaviour using psql regression tests. --- doc/src/sgml/ref/psql-ref.sgml | 66 +++++- src/bin/psql/command.c | 77 +++++++ src/bin/psql/common.c | 98 ++++++++- src/bin/psql/help.c | 3 + src/bin/psql/prompt.c | 12 +- src/bin/psql/settings.h | 4 + src/bin/psql/tab-complete.in.c | 4 +- src/test/regress/expected/psql.out | 335 +++++++++++++++++++++++++++++ src/test/regress/sql/psql.sql | 209 ++++++++++++++++++ 9 files changed, 799 insertions(+), 9 deletions(-) diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml index e42073ed748..4b45a3117f9 100644 --- a/doc/src/sgml/ref/psql-ref.sgml +++ b/doc/src/sgml/ref/psql-ref.sgml @@ -3562,6 +3562,65 @@ testdb=> <userinput>\setenv LESS -imx4F</userinput> </listitem> </varlistentry> + <varlistentry id="app-psql-meta-command-pipeline"> + <term><literal>\startpipeline</literal></term> + <term><literal>\syncpipeline</literal></term> + <term><literal>\endpipeline</literal></term> + + <listitem> + <para> + This group of commands implements pipelining of SQL statements. + A pipeline must begin with a <command>\startpipeline</command> + and end with an <command>\endpipeline</command>. In between there + may be any number of <command>\syncpipeline</command> commands, + which sends a <link linkend="protocol-flow-ext-query">sync message</link> + without ending the ongoing pipeline and flushing the send buffer. + In pipeline mode, statements are sent to the server without waiting + for the results of previous statements. See + <xref linkend="libpq-pipeline-mode"/> for more details. + </para> + + <para> + Pipeline mode requires the use of extended query protocol. All queries need + to be sent using the meta-commands <literal>\bind</literal>, + <literal>\bind_named</literal>, <literal>\close</literal> or + <literal>\parse</literal>. While a pipeline is ongoing, + <literal>\g</literal> will append the current query buffer to the pipeline and + other meta-commands like <literal>\gx</literal> or <literal>\gdesc</literal> + are not allowed in pipeline mode. + </para> + + <para> + </para> + + <para> + Example: +<programlisting> +\startpipeline +-- Pipe a Parse, Bind and Execute of "SELECT 1" +SELECT 1 \bind \g +-- Pipe a Parse of "SELECT $1", storing the result in the prepared statement 'stmt1' +SELECT $1 \parse stmt1 +-- Pipe a Bind and Execute of the prepared statement 'stmt1' with parameter 1 +\bind_named stmt1 1 \g +-- Pipe a Parse, Bind and Execute of "SELECT pg_current_xact_id()" +SELECT pg_current_xact_id() \bind \g +-- Pipe a synchronisation point. This will commit the implicit transaction +-- block started by the pipeline +\syncpipeline +-- Pipe a Parse, Bind and Execute of SELECT pg_current_xact_id() +-- This will display a different xid as a new transaction block +-- was started after the synchronisation point +SELECT pg_current_xact_id() \bind \g +-- Pipe a Close of the prepared statement 'stmt1' +\close stmt1 +-- End the pipeline, sending all piped commands to the server and process the results +\endpipeline +</programlisting></para> + + </listitem> + </varlistentry> + <varlistentry id="app-psql-meta-command-t-lc"> <term><literal>\t</literal></term> @@ -4734,9 +4793,10 @@ testdb=> <userinput>INSERT INTO my_table VALUES (:'content');</userinput> <para> Transaction status: an empty string when not in a transaction block, or <literal>*</literal> when in a transaction block, or - <literal>!</literal> when in a failed transaction block, or <literal>?</literal> - when the transaction state is indeterminate (for example, because - there is no connection). + <literal>|</literal> when in a pipeline, or <literal>!</literal> + when in a failed transaction block, or <literal>?</literal> when + the transaction state is indeterminate (for example, because there + is no connection). </para> </listitem> </varlistentry> diff --git a/src/bin/psql/command.c b/src/bin/psql/command.c index 1f3cbb11f7c..067329d241a 100644 --- a/src/bin/psql/command.c +++ b/src/bin/psql/command.c @@ -90,6 +90,7 @@ static backslashResult exec_command_else(PsqlScanState scan_state, ConditionalSt PQExpBuffer query_buf); static backslashResult exec_command_endif(PsqlScanState scan_state, ConditionalStack cstack, PQExpBuffer query_buf); +static backslashResult exec_command_endpipeline(PsqlScanState scan_state, bool active_branch); static backslashResult exec_command_encoding(PsqlScanState scan_state, bool active_branch); static backslashResult exec_command_errverbose(PsqlScanState scan_state, bool active_branch); static backslashResult exec_command_f(PsqlScanState scan_state, bool active_branch); @@ -132,6 +133,8 @@ static backslashResult exec_command_setenv(PsqlScanState scan_state, bool active const char *cmd); static backslashResult exec_command_sf_sv(PsqlScanState scan_state, bool active_branch, const char *cmd, bool is_func); +static backslashResult exec_command_startpipeline(PsqlScanState scan_state, bool active_branch); +static backslashResult exec_command_syncpipeline(PsqlScanState scan_state, bool active_branch); static backslashResult exec_command_t(PsqlScanState scan_state, bool active_branch); static backslashResult exec_command_T(PsqlScanState scan_state, bool active_branch); static backslashResult exec_command_timing(PsqlScanState scan_state, bool active_branch); @@ -351,6 +354,8 @@ exec_command(const char *cmd, status = exec_command_else(scan_state, cstack, query_buf); else if (strcmp(cmd, "endif") == 0) status = exec_command_endif(scan_state, cstack, query_buf); + else if (strcmp(cmd, "endpipeline") == 0) + status = exec_command_endpipeline(scan_state, active_branch); else if (strcmp(cmd, "encoding") == 0) status = exec_command_encoding(scan_state, active_branch); else if (strcmp(cmd, "errverbose") == 0) @@ -408,6 +413,10 @@ exec_command(const char *cmd, status = exec_command_sf_sv(scan_state, active_branch, cmd, true); else if (strcmp(cmd, "sv") == 0 || strcmp(cmd, "sv+") == 0) status = exec_command_sf_sv(scan_state, active_branch, cmd, false); + else if (strcmp(cmd, "startpipeline") == 0) + status = exec_command_startpipeline(scan_state, active_branch); + else if (strcmp(cmd, "syncpipeline") == 0) + status = exec_command_syncpipeline(scan_state, active_branch); else if (strcmp(cmd, "t") == 0) status = exec_command_t(scan_state, active_branch); else if (strcmp(cmd, "T") == 0) @@ -1526,6 +1535,13 @@ exec_command_g(PsqlScanState scan_state, bool active_branch, const char *cmd) if (status == PSQL_CMD_SKIP_LINE && active_branch) { + if (strcmp(cmd, "gx") == 0 && PQpipelineStatus(pset.db) == PQ_PIPELINE_ON) + { + pg_log_error("\\gx not allowed in pipeline mode"); + clean_extended_state(); + return PSQL_CMD_ERROR; + } + if (!fname) pset.gfname = NULL; else @@ -1689,6 +1705,12 @@ exec_command_gexec(PsqlScanState scan_state, bool active_branch) if (active_branch) { + if (PQpipelineStatus(pset.db) == PQ_PIPELINE_ON) + { + pg_log_error("\\gexec not allowed in pipeline mode"); + clean_extended_state(); + return PSQL_CMD_ERROR; + } pset.gexec_flag = true; status = PSQL_CMD_SEND; } @@ -1709,6 +1731,13 @@ exec_command_gset(PsqlScanState scan_state, bool active_branch) char *prefix = psql_scan_slash_option(scan_state, OT_NORMAL, NULL, false); + if (PQpipelineStatus(pset.db) == PQ_PIPELINE_ON) + { + pg_log_error("\\gset not allowed in pipeline mode"); + clean_extended_state(); + return PSQL_CMD_ERROR; + } + if (prefix) pset.gset_prefix = prefix; else @@ -2672,6 +2701,54 @@ exec_command_sf_sv(PsqlScanState scan_state, bool active_branch, return status; } +/* + * \startpipeline -- enter pipeline mode + */ +static backslashResult +exec_command_startpipeline(PsqlScanState scan_state, bool active_branch) +{ + if (active_branch) + { + pset.send_mode = PSQL_START_PIPELINE_MODE; + } + else + ignore_slash_options(scan_state); + + return PSQL_CMD_SEND; +} + +/* + * \syncpipeline -- send a sync message to an active pipeline + */ +static backslashResult +exec_command_syncpipeline(PsqlScanState scan_state, bool active_branch) +{ + if (active_branch) + { + pset.send_mode = PSQL_SEND_PIPELINE_SYNC; + } + else + ignore_slash_options(scan_state); + + return PSQL_CMD_SEND; +} + +/* + * \endpipeline -- end pipeline mode + */ +static backslashResult +exec_command_endpipeline(PsqlScanState scan_state, bool active_branch) +{ + if (active_branch) + { + pset.send_mode = PSQL_END_PIPELINE_MODE; + } + else + ignore_slash_options(scan_state); + + return PSQL_CMD_SEND; +} + /* * \t -- turn off table headers and row count */ diff --git a/src/bin/psql/common.c b/src/bin/psql/common.c index 8a9211db41a..3c0ad4dd9ce 100644 --- a/src/bin/psql/common.c +++ b/src/bin/psql/common.c @@ -415,6 +415,8 @@ AcceptResult(const PGresult *result, bool show_error) case PGRES_EMPTY_QUERY: case PGRES_COPY_IN: case PGRES_COPY_OUT: + case PGRES_PIPELINE_SYNC: + case PGRES_PIPELINE_ABORTED: /* Fine, do nothing */ OK = true; break; @@ -1418,6 +1420,28 @@ DescribeQuery(const char *query, double *elapsed_msec) return OK; } +/* + * Read and discard all results until a synchronisation point is found. + */ +static PGresult * +discardUntilSync(void) +{ + for (;;) + { + PGresult *res = PQgetResult(pset.db); + ExecStatusType result_status = PQresultStatus(res); + + if (result_status == PGRES_PIPELINE_SYNC) + return res; + + /* + * An aborted pipeline will have either NULL results or results in an + * PGRES_PIPELINE_ABORTED status + */ + Assert(res == NULL || result_status == PGRES_PIPELINE_ABORTED); + PQclear(res); + } +} /* * ExecQueryAndProcessResults: utility function for use by SendQuery() @@ -1451,6 +1475,7 @@ ExecQueryAndProcessResults(const char *query, bool timing = pset.timing; bool success = false; bool return_early = false; + bool process_pipeline = false; instr_time before, after; PGresult *result; @@ -1484,6 +1509,21 @@ ExecQueryAndProcessResults(const char *query, (const char *const *) pset.bind_params, NULL, NULL, 0); break; + case PSQL_START_PIPELINE_MODE: + success = PQenterPipelineMode(pset.db); + break; + case PSQL_END_PIPELINE_MODE: + success = PQpipelineSync(pset.db); + /* End of the pipeline, all queued commands need to be processed */ + process_pipeline = true; + if (success) + pset.num_syncs++; + break; + case PSQL_SEND_PIPELINE_SYNC: + success = PQsendPipelineSync(pset.db); + if (success) + pset.num_syncs++; + break; case PSQL_SEND_QUERY: success = PQsendQuery(pset.db, query); break; @@ -1501,6 +1541,15 @@ ExecQueryAndProcessResults(const char *query, return -1; } + if (!process_pipeline && PQpipelineStatus(pset.db) == PQ_PIPELINE_ON) + { + /* + * We're in a pipeline and haven't received a pipeline end so there's + * no result to process yet. + */ + return 0; + } + /* * Fetch the result in chunks if FETCH_COUNT is set, except when: * @@ -1585,6 +1634,15 @@ ExecQueryAndProcessResults(const char *query, * ignore manually. */ result = NULL; + else if (process_pipeline) + { + /* + * We have an error within a pipeline. All commands are + * aborted until the next synchronisation point. We need to + * consume all results until this synchronisation point. + */ + result = discardUntilSync(); + } else result = PQgetResult(pset.db); @@ -1771,12 +1829,38 @@ ExecQueryAndProcessResults(const char *query, } } + if (result_status == PGRES_PIPELINE_SYNC) + { + /* We have a sync response, decrease the sync counter */ + pset.num_syncs--; + + /* + * After a synchronisation point, reset success state to print + * possible successful results + */ + success = true; + /* If all syncs were processed, exit pipeline mode */ + if (pset.num_syncs <= 0) + success &= PQexitPipelineMode(pset.db); + } + /* * Check PQgetResult() again. In the typical case of a single-command * string, it will return NULL. Otherwise, we'll have other results * to process. We need to do that to check whether this is the last. */ next_result = PQgetResult(pset.db); + if (process_pipeline && result_status != PGRES_PIPELINE_SYNC) + { + /* + * In pipeline mode, a NULL result indicates the end of the + * current query being processed. We need to call PQgetResult a + * second time to move to the next response. + */ + Assert(next_result == NULL); + next_result = PQgetResult(pset.db); + } + last = (next_result == NULL); /* @@ -1798,8 +1882,12 @@ ExecQueryAndProcessResults(const char *query, *elapsed_msec = INSTR_TIME_GET_MILLISEC(after); } - /* this may or may not print something depending on settings */ - if (result != NULL) + /* + * This may or may not print something depending on settings. A + * pipeline sync will have a non null result but doesn't have anything + * to print, thus we ignore them + */ + if (result != NULL && result_status != PGRES_PIPELINE_SYNC) { /* * If results need to be printed into the file specified by \g, @@ -1837,6 +1925,9 @@ ExecQueryAndProcessResults(const char *query, /* close \g file if we opened it */ CloseGOutput(gfile_fout, gfile_is_pipe); + /* After query process, pipeline num_syncs should be 0 */ + Assert(pset.num_syncs == 0); + /* may need this to recover from conn loss during COPY */ if (!CheckConnection()) return -1; @@ -2296,6 +2387,9 @@ clean_extended_state(void) free(pset.stmtName); pset.bind_params = NULL; break; + case PSQL_START_PIPELINE_MODE: /* \startpipeline */ + case PSQL_END_PIPELINE_MODE: /* \endpipeline */ + case PSQL_SEND_PIPELINE_SYNC: /* \syncpipeline */ case PSQL_SEND_QUERY: break; } diff --git a/src/bin/psql/help.c b/src/bin/psql/help.c index 3f4afc2d141..e550a29297c 100644 --- a/src/bin/psql/help.c +++ b/src/bin/psql/help.c @@ -167,6 +167,7 @@ slashUsage(unsigned short int pager) HELP0(" \\close STMT_NAME close an existing prepared statement\n"); HELP0(" \\copyright show PostgreSQL usage and distribution terms\n"); HELP0(" \\crosstabview [COLUMNS] execute query and display result in crosstab\n"); + HELP0(" \\endpipeline exit pipeline mode\n"); HELP0(" \\errverbose show most recent error message at maximum verbosity\n"); HELP0(" \\g [(OPTIONS)] [FILE] execute query (and send result to file or |pipe);\n" " \\g with no arguments is equivalent to a semicolon\n"); @@ -176,6 +177,8 @@ slashUsage(unsigned short int pager) HELP0(" \\gx [(OPTIONS)] [FILE] as \\g, but forces expanded output mode\n"); HELP0(" \\parse STMT_NAME create a prepared statement\n"); HELP0(" \\q quit psql\n"); + HELP0(" \\startpipeline enter pipeline mode\n"); + HELP0(" \\syncpipeline add a synchronisation point to an ongoing pipeline\n"); HELP0(" \\watch [[i=]SEC] [c=N] [m=MIN]\n" " execute query every SEC seconds, up to N times,\n" " stop if less than MIN rows are returned\n"); diff --git a/src/bin/psql/prompt.c b/src/bin/psql/prompt.c index 0d99d00ac92..f3c1f319106 100644 --- a/src/bin/psql/prompt.c +++ b/src/bin/psql/prompt.c @@ -41,7 +41,7 @@ * or a ! if session is not connected to a database; * in prompt2 -, *, ', or "; * in prompt3 nothing - * %x - transaction status: empty, *, !, ? (unknown or no connection) + * %x - transaction status: empty, *, |, !, ? (unknown or no connection) * %l - The line number inside the current statement, starting from 1. * %? - the error code of the last query (not yet implemented) * %% - a percent sign @@ -231,9 +231,17 @@ get_prompt(promptStatus_t status, ConditionalStack cstack) switch (PQtransactionStatus(pset.db)) { case PQTRANS_IDLE: - buf[0] = '\0'; + if (PQpipelineStatus(pset.db) == PQ_PIPELINE_ON) + buf[0] = '|'; + else + buf[0] = '\0'; break; case PQTRANS_ACTIVE: + if (PQpipelineStatus(pset.db) == PQ_PIPELINE_ON) + buf[0] = '|'; + else + buf[0] = '*'; + break; case PQTRANS_INTRANS: buf[0] = '*'; break; diff --git a/src/bin/psql/settings.h b/src/bin/psql/settings.h index a22de8ef78e..55247c4dc33 100644 --- a/src/bin/psql/settings.h +++ b/src/bin/psql/settings.h @@ -69,6 +69,9 @@ typedef enum PSQL_SEND_EXTENDED_PARSE, PSQL_SEND_EXTENDED_QUERY_PARAMS, PSQL_SEND_EXTENDED_QUERY_PREPARED, + PSQL_SEND_PIPELINE_SYNC, + PSQL_START_PIPELINE_MODE, + PSQL_END_PIPELINE_MODE, } PSQL_SEND_MODE; typedef enum @@ -108,6 +111,7 @@ typedef struct _psqlSettings PSQL_SEND_MODE send_mode; /* one-shot request to send query with normal * or extended query protocol */ int bind_nparams; /* number of parameters */ + int num_syncs; /* number of ongoing syncs */ char **bind_params; /* parameters for extended query protocol call */ char *stmtName; /* prepared statement name used for extended * query protocol commands */ diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c index fad2277991d..742d2627afc 100644 --- a/src/bin/psql/tab-complete.in.c +++ b/src/bin/psql/tab-complete.in.c @@ -1867,7 +1867,7 @@ psql_completion(const char *text, int start, int end) "\\drds", "\\drg", "\\dRs", "\\dRp", "\\ds", "\\dt", "\\dT", "\\dv", "\\du", "\\dx", "\\dX", "\\dy", "\\echo", "\\edit", "\\ef", "\\elif", "\\else", "\\encoding", - "\\endif", "\\errverbose", "\\ev", + "\\endif", "\\endpipeline", "\\errverbose", "\\ev", "\\f", "\\g", "\\gdesc", "\\getenv", "\\gexec", "\\gset", "\\gx", "\\help", "\\html", @@ -1877,7 +1877,7 @@ psql_completion(const char *text, int start, int end) "\\parse", "\\password", "\\print", "\\prompt", "\\pset", "\\qecho", "\\quit", "\\reset", - "\\s", "\\set", "\\setenv", "\\sf", "\\sv", + "\\s", "\\set", "\\setenv", "\\sf", "\\startpipeline", "\\sv", "\\syncpipeline", "\\t", "\\T", "\\timing", "\\unset", "\\x", diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out index 36dc31c16c4..6e05f908484 100644 --- a/src/test/regress/expected/psql.out +++ b/src/test/regress/expected/psql.out @@ -6828,3 +6828,338 @@ CREATE TABLE defprivs (a int); \pset null '' DROP TABLE defprivs; +-- pipelining +CREATE TABLE psql_pipeline(a INTEGER PRIMARY KEY, s TEXT); +-- single query +\startpipeline +SELECT $1 \bind 'val1' \g +\endpipeline + ?column? +---------- + val1 +(1 row) + +-- multiple queries +\startpipeline +SELECT $1 \bind 'val1' \g +SELECT $1, $2 \bind 'val2' 'val3' \g +SELECT $1, $2 \bind 'val2' 'val3' \g +\endpipeline + ?column? +---------- + val1 +(1 row) + + ?column? | ?column? +----------+---------- + val2 | val3 +(1 row) + + ?column? | ?column? +----------+---------- + val2 | val3 +(1 row) + +-- send multiple syncs +\startpipeline +SELECT $1 \bind 'val1' \g +\syncpipeline +\syncpipeline +SELECT $1, $2 \bind 'val2' 'val3' \g +\syncpipeline +SELECT $1, $2 \bind 'val4' 'val5' \g +\endpipeline + ?column? +---------- + val1 +(1 row) + + ?column? | ?column? +----------+---------- + val2 | val3 +(1 row) + + ?column? | ?column? +----------+---------- + val4 | val5 +(1 row) + +-- startpipeline shouldn't have any effect if already in a pipeline +\startpipeline +\startpipeline +SELECT $1 \bind 'val1' \g +\endpipeline + ?column? +---------- + val1 +(1 row) + +-- Convert an implicit tx block to an explicit tx block +\startpipeline +INSERT INTO psql_pipeline VALUES ($1) \bind 1 \g +BEGIN \bind \g +INSERT INTO psql_pipeline VALUES ($1) \bind 2 \g +ROLLBACK \bind \g +\endpipeline +-- Multiple explicit transactions +\startpipeline +BEGIN \bind \g +INSERT INTO psql_pipeline VALUES ($1) \bind 1 \g +ROLLBACK \bind \g +BEGIN \bind \g +INSERT INTO psql_pipeline VALUES ($1) \bind 1 \g +COMMIT \bind \g +\endpipeline +-- COPY FROM STDIN +\startpipeline +SELECT $1 \bind 'val1' \g +COPY psql_pipeline FROM STDIN \bind \g +\endpipeline + ?column? +---------- + val1 +(1 row) + +-- COPY TO STDOUT +\startpipeline +SELECT $1 \bind 'val1' \g +copy psql_pipeline TO STDOUT \bind \g +SELECT $1 \bind 'val2' \g +\endpipeline + ?column? +---------- + val1 +(1 row) + +1 \N +2 test2 +3 test3 + ?column? +---------- + val2 +(1 row) + +-- Use \parse and \bind_named +\startpipeline +SELECT $1 \parse '' +SELECT $1, $2 \parse '' +SELECT $2 \parse pipeline_1 +\bind_named '' 1 2 \g +\bind_named pipeline_1 2 \g +\endpipeline +ERROR: could not determine data type of parameter $1 +-- pipelining errors +-- endpipeline outside of pipeline should fail +\endpipeline +cannot send pipeline when not in pipeline mode +-- Query using simple protocol should not be sent and should leave the pipeline usable +\startpipeline +SELECT 1; +PQsendQuery not allowed in pipeline mode +SELECT $1 \bind 'val1' \g +\endpipeline + ?column? +---------- + val1 +(1 row) + +-- After an aborted pipeline, commands after a sync should be displayed +\startpipeline +SELECT $1 \bind \g +\syncpipeline +SELECT $1 \bind 1 \g +\endpipeline +ERROR: bind message supplies 0 parameters, but prepared statement "" requires 1 + ?column? +---------- + 1 +(1 row) + +-- Incorrect number of parameters, the pipeline will be aborted and following queries won't be executed +\startpipeline +SELECT \bind 'val1' \g +SELECT $1 \bind 'val1' \g +\endpipeline +ERROR: bind message supplies 1 parameters, but prepared statement "" requires 0 +-- An explicit transaction with an error needs to be rollbacked after the pipeline +\startpipeline +BEGIN \bind \g +INSERT INTO psql_pipeline VALUES ($1) \bind 1 \g +ROLLBACK \bind \g +\endpipeline +ERROR: duplicate key value violates unique constraint "psql_pipeline_pkey" +DETAIL: Key (a)=(1) already exists. +ROLLBACK; +-- \watch sends a simple query which won't be allowed within a pipeline +\startpipeline +SELECT \bind \g +\watch 1 +PQsendQuery not allowed in pipeline mode + +\endpipeline +-- +(1 row) + +-- \gdesc should fail as synchronous commands are not allowed in pipeline, pipeline should still be usable +\startpipeline +SELECT $1 \bind 1 \gdesc +synchronous command execution functions are not allowed in pipeline mode +SELECT $1 \bind 1 \g +\endpipeline + ?column? +---------- + 1 +(1 row) + +-- \gset is not allowed, pipeline should still be usable +\startpipeline +SELECT $1 as i, $2 as j \parse '' +SELECT $1 as k, $2 as l \parse 'second' +\bind_named '' 1 2 \gset +\gset not allowed in pipeline mode +\bind_named second 1 2 \gset pref02_ \echo :pref02_i :pref02_j +\gset not allowed in pipeline mode +\bind_named '' 1 2 \g +\endpipeline + i | j +---+--- + 1 | 2 +(1 row) + +-- \gx is not allowed, pipeline should still be usable +\startpipeline +SELECT $1 \bind 1 \gx +\gx not allowed in pipeline mode +\reset +SELECT $1 \bind 1 \g +\endpipeline + ?column? +---------- + 1 +(1 row) + +-- \gexec is not allowed, pipeline should still be usable +\startpipeline +SELECT 'INSERT INTO psql_pipeline(a) SELECT generate_series(1, 10)' \parse 'insert_stmt' +\bind_named insert_stmt \gexec +\gexec not allowed in pipeline mode +\bind_named insert_stmt \g +SELECT COUNT(*) FROM psql_pipeline \bind \g +\endpipeline + ?column? +------------------------------------------------------------ + INSERT INTO psql_pipeline(a) SELECT generate_series(1, 10) +(1 row) + + count +------- + 3 +(1 row) + +-- pipelining and transaction block behaviour +-- set local will issue a warning when modifying a GUC outside of a transaction block +-- The change will still be valid as a pipeline runs within an implicit transaction block +-- Sending a sync will commit the implicit transaction block. The first command after a sync +-- won't be seen as belonging to a pipeline. +\startpipeline +SET LOCAL statement_timeout='1h' \bind \g +SHOW statement_timeout \bind \g +\syncpipeline +SHOW statement_timeout \bind \g +SET LOCAL statement_timeout='2h' \bind \g +SHOW statement_timeout \bind \g +\endpipeline +WARNING: SET LOCAL can only be used in transaction blocks + statement_timeout +------------------- + 1h +(1 row) + + statement_timeout +------------------- + 0 +(1 row) + + statement_timeout +------------------- + 2h +(1 row) + +-- Reindex concurrently is forbidden in the middle of a pipeline +\startpipeline +SELECT $1 \bind 1 \g +REINDEX TABLE CONCURRENTLY psql_pipeline \bind \g +SELECT $1 \bind 2 \g +\endpipeline + ?column? +---------- + 1 +(1 row) + +ERROR: REINDEX CONCURRENTLY cannot run inside a transaction block +-- Reindex concurrently will work if it's the first command of a pipeline +\startpipeline +REINDEX TABLE CONCURRENTLY psql_pipeline \bind \g +SELECT $1 \bind 2 \g +\endpipeline + ?column? +---------- + 2 +(1 row) + +-- subtransactions are not allowed in pipeline mode +\startpipeline +SAVEPOINT a \bind \g +SELECT $1 \bind 1 \g +ROLLBACK TO SAVEPOINT a \bind \g +SELECT $1 \bind 2 \g +\endpipeline +ERROR: SAVEPOINT can only be used in transaction blocks +-- Lock command will fail as first pipeline command is not seen as a transaction block +\startpipeline +LOCK psql_pipeline \bind \g +SELECT $1 \bind 2 \g +\endpipeline +ERROR: LOCK TABLE can only be used in transaction blocks +-- Lock command will succeed after the first command as pipeline will be seen as an implicit transaction block +\startpipeline +SELECT $1 \bind 1 \g +LOCK psql_pipeline \bind \g +SELECT $1 \bind 2 \g +\endpipeline + ?column? +---------- + 1 +(1 row) + + ?column? +---------- + 2 +(1 row) + +-- Vacuum command will work as the first command +\startpipeline +VACUUM psql_pipeline \bind \g +\endpipeline +-- Vacuum command will fail within pipeline implicit transaction +\startpipeline +SELECT 1 \bind \g +VACUUM psql_pipeline \bind \g +\endpipeline + ?column? +---------- + 1 +(1 row) + +ERROR: VACUUM cannot run inside a transaction block +-- Vacuum command will work after a sync +\startpipeline +SELECT 1 \bind \g +\syncpipeline +VACUUM psql_pipeline \bind \g +\endpipeline + ?column? +---------- + 1 +(1 row) + diff --git a/src/test/regress/sql/psql.sql b/src/test/regress/sql/psql.sql index c5021fc0b13..e9bd8972996 100644 --- a/src/test/regress/sql/psql.sql +++ b/src/test/regress/sql/psql.sql @@ -1929,3 +1929,212 @@ CREATE TABLE defprivs (a int); \z defprivs \pset null '' DROP TABLE defprivs; + +-- pipelining +CREATE TABLE psql_pipeline(a INTEGER PRIMARY KEY, s TEXT); + +-- single query +\startpipeline +SELECT $1 \bind 'val1' \g +\endpipeline + +-- multiple queries +\startpipeline +SELECT $1 \bind 'val1' \g +SELECT $1, $2 \bind 'val2' 'val3' \g +SELECT $1, $2 \bind 'val2' 'val3' \g +\endpipeline + +-- send multiple syncs +\startpipeline +SELECT $1 \bind 'val1' \g +\syncpipeline +\syncpipeline +SELECT $1, $2 \bind 'val2' 'val3' \g +\syncpipeline +SELECT $1, $2 \bind 'val4' 'val5' \g +\endpipeline + +-- startpipeline shouldn't have any effect if already in a pipeline +\startpipeline +\startpipeline +SELECT $1 \bind 'val1' \g +\endpipeline + +-- Convert an implicit tx block to an explicit tx block +\startpipeline +INSERT INTO psql_pipeline VALUES ($1) \bind 1 \g +BEGIN \bind \g +INSERT INTO psql_pipeline VALUES ($1) \bind 2 \g +ROLLBACK \bind \g +\endpipeline + +-- Multiple explicit transactions +\startpipeline +BEGIN \bind \g +INSERT INTO psql_pipeline VALUES ($1) \bind 1 \g +ROLLBACK \bind \g +BEGIN \bind \g +INSERT INTO psql_pipeline VALUES ($1) \bind 1 \g +COMMIT \bind \g +\endpipeline + +-- COPY FROM STDIN +\startpipeline +SELECT $1 \bind 'val1' \g +COPY psql_pipeline FROM STDIN \bind \g +\endpipeline +2 test2 +3 test3 +\. + +-- COPY TO STDOUT +\startpipeline +SELECT $1 \bind 'val1' \g +copy psql_pipeline TO STDOUT \bind \g +SELECT $1 \bind 'val2' \g +\endpipeline + +-- Use \parse and \bind_named +\startpipeline +SELECT $1 \parse '' +SELECT $1, $2 \parse '' +SELECT $2 \parse pipeline_1 +\bind_named '' 1 2 \g +\bind_named pipeline_1 2 \g +\endpipeline + +-- pipelining errors + +-- endpipeline outside of pipeline should fail +\endpipeline + +-- Query using simple protocol should not be sent and should leave the pipeline usable +\startpipeline +SELECT 1; +SELECT $1 \bind 'val1' \g +\endpipeline + +-- After an aborted pipeline, commands after a sync should be displayed +\startpipeline +SELECT $1 \bind \g +\syncpipeline +SELECT $1 \bind 1 \g +\endpipeline + +-- Incorrect number of parameters, the pipeline will be aborted and following queries won't be executed +\startpipeline +SELECT \bind 'val1' \g +SELECT $1 \bind 'val1' \g +\endpipeline + +-- An explicit transaction with an error needs to be rollbacked after the pipeline +\startpipeline +BEGIN \bind \g +INSERT INTO psql_pipeline VALUES ($1) \bind 1 \g +ROLLBACK \bind \g +\endpipeline +ROLLBACK; + +-- \watch sends a simple query which won't be allowed within a pipeline +\startpipeline +SELECT \bind \g +\watch 1 +\endpipeline + +-- \gdesc should fail as synchronous commands are not allowed in pipeline, pipeline should still be usable +\startpipeline +SELECT $1 \bind 1 \gdesc +SELECT $1 \bind 1 \g +\endpipeline + +-- \gset is not allowed, pipeline should still be usable +\startpipeline +SELECT $1 as i, $2 as j \parse '' +SELECT $1 as k, $2 as l \parse 'second' +\bind_named '' 1 2 \gset +\bind_named second 1 2 \gset pref02_ \echo :pref02_i :pref02_j +\bind_named '' 1 2 \g +\endpipeline + +-- \gx is not allowed, pipeline should still be usable +\startpipeline +SELECT $1 \bind 1 \gx +\reset +SELECT $1 \bind 1 \g +\endpipeline + +-- \gexec is not allowed, pipeline should still be usable +\startpipeline +SELECT 'INSERT INTO psql_pipeline(a) SELECT generate_series(1, 10)' \parse 'insert_stmt' +\bind_named insert_stmt \gexec +\bind_named insert_stmt \g +SELECT COUNT(*) FROM psql_pipeline \bind \g +\endpipeline + +-- pipelining and transaction block behaviour + +-- set local will issue a warning when modifying a GUC outside of a transaction block +-- The change will still be valid as a pipeline runs within an implicit transaction block +-- Sending a sync will commit the implicit transaction block. The first command after a sync +-- won't be seen as belonging to a pipeline. +\startpipeline +SET LOCAL statement_timeout='1h' \bind \g +SHOW statement_timeout \bind \g +\syncpipeline +SHOW statement_timeout \bind \g +SET LOCAL statement_timeout='2h' \bind \g +SHOW statement_timeout \bind \g +\endpipeline + +-- Reindex concurrently is forbidden in the middle of a pipeline +\startpipeline +SELECT $1 \bind 1 \g +REINDEX TABLE CONCURRENTLY psql_pipeline \bind \g +SELECT $1 \bind 2 \g +\endpipeline + +-- Reindex concurrently will work if it's the first command of a pipeline +\startpipeline +REINDEX TABLE CONCURRENTLY psql_pipeline \bind \g +SELECT $1 \bind 2 \g +\endpipeline + +-- subtransactions are not allowed in pipeline mode +\startpipeline +SAVEPOINT a \bind \g +SELECT $1 \bind 1 \g +ROLLBACK TO SAVEPOINT a \bind \g +SELECT $1 \bind 2 \g +\endpipeline + +-- Lock command will fail as first pipeline command is not seen as a transaction block +\startpipeline +LOCK psql_pipeline \bind \g +SELECT $1 \bind 2 \g +\endpipeline + +-- Lock command will succeed after the first command as pipeline will be seen as an implicit transaction block +\startpipeline +SELECT $1 \bind 1 \g +LOCK psql_pipeline \bind \g +SELECT $1 \bind 2 \g +\endpipeline + +-- Vacuum command will work as the first command +\startpipeline +VACUUM psql_pipeline \bind \g +\endpipeline + +-- Vacuum command will fail within pipeline implicit transaction +\startpipeline +SELECT 1 \bind \g +VACUUM psql_pipeline \bind \g +\endpipeline + +-- Vacuum command will work after a sync +\startpipeline +SELECT 1 \bind \g +\syncpipeline +VACUUM psql_pipeline \bind \g +\endpipeline -- 2.39.5 (Apple Git-154) ^ permalink raw reply [nested|flat] 72+ messages in thread
end of thread, other threads:[~2024-11-28 09:22 UTC | newest] Thread overview: 72+ messages (download: mbox mbox.gz follow: Atom feed) -- links below jump to the message on this page -- 2020-01-10 06:08 [PATCH v1 3/3] CatCache expiration feature. Kyotaro Horiguchi <[email protected]> 2020-01-10 06:08 [PATCH 4/4] CatCache expiration feature. Kyotaro Horiguchi <[email protected]> 2020-01-10 06:08 [PATCH v2 3/3] CatCache expiration feature. Kyotaro Horiguchi <[email protected]> 2020-01-10 06:08 [PATCH v3 3/3] CatCache expiration feature. Kyotaro Horiguchi <[email protected]> 2020-11-06 08:27 [PATCH v5] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-06 08:27 [PATCH v4] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v7 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v7 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v7 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v6 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v6 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v6 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v7 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v6 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v7 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v6 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v7 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v6 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v7 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v6 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v6 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v7 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v7 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v7 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v7 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v6 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v7 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v6 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v7 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v6 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v6 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v6 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v5 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v7 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v7 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v6 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v7 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v7 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v6 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v7 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v6 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v7 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v6 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v6 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v6 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v6 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v7 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v6 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2020-11-18 07:54 [PATCH v7 1/3] CatCache expiration feature Kyotaro Horiguchi <[email protected]> 2021-01-27 11:08 [PATCH v8 1/1] CatCache expiration feature Heikki Linnakangas <[email protected]> 2021-01-27 11:08 [PATCH v8 1/1] CatCache expiration feature Heikki Linnakangas <[email protected]> 2021-01-27 11:08 [PATCH v8 1/1] CatCache expiration feature Heikki Linnakangas <[email protected]> 2021-01-27 11:08 [PATCH v8 1/1] CatCache expiration feature Heikki Linnakangas <[email protected]> 2021-01-27 11:08 [PATCH v8 1/1] CatCache expiration feature Heikki Linnakangas <[email protected]> 2021-01-27 11:08 [PATCH v8 1/1] CatCache expiration feature Heikki Linnakangas <[email protected]> 2021-01-27 11:08 [PATCH v8 1/1] CatCache expiration feature Heikki Linnakangas <[email protected]> 2021-01-27 11:08 [PATCH v8 1/1] CatCache expiration feature Heikki Linnakangas <[email protected]> 2021-01-27 11:08 [PATCH v8 1/1] CatCache expiration feature Heikki Linnakangas <[email protected]> 2021-01-27 11:08 [PATCH v8 1/1] CatCache expiration feature Heikki Linnakangas <[email protected]> 2021-01-27 11:08 [PATCH v9] CatCache expiration feature Heikki Linnakangas <[email protected]> 2021-01-27 11:08 [PATCH v8 1/1] CatCache expiration feature Heikki Linnakangas <[email protected]> 2021-01-27 11:08 [PATCH v8 1/1] CatCache expiration feature Heikki Linnakangas <[email protected]> 2021-01-27 11:08 [PATCH v8 1/1] CatCache expiration feature Heikki Linnakangas <[email protected]> 2021-01-27 11:08 [PATCH v8 1/1] CatCache expiration feature Heikki Linnakangas <[email protected]> 2021-01-27 11:08 [PATCH v8 1/1] CatCache expiration feature Heikki Linnakangas <[email protected]> 2021-01-27 11:08 [PATCH v8 1/1] CatCache expiration feature Heikki Linnakangas <[email protected]> 2021-01-27 11:08 [PATCH v8 1/1] CatCache expiration feature Heikki Linnakangas <[email protected]> 2021-01-27 11:08 [PATCH v8 1/1] CatCache expiration feature Heikki Linnakangas <[email protected]> 2021-01-27 11:08 [PATCH v8 1/1] CatCache expiration feature Heikki Linnakangas <[email protected]> 2021-01-27 11:08 [PATCH v8 1/1] CatCache expiration feature Heikki Linnakangas <[email protected]> 2021-01-27 11:08 [PATCH v8 1/1] CatCache expiration feature Heikki Linnakangas <[email protected]> 2024-11-28 09:22 Re: Add Pipelining support in psql Anthonin Bonnefoy <[email protected]>
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