Subject: [PATCH v17 1/2] vacuum errcontext to show block being processed

From: Justin Pryzby <[email-masked]>
Date: Thu, 12 Dec 2019 20:54:37 -0600

As requested here.
https://www.postgresql.org/message-id/20190807235154.erbmr4o4bo6vgnjv%40alap3.anarazel.de
---
 src/backend/access/heap/vacuumlazy.c | 117 +++++++++++++++++++++++++++++++++++
 1 file changed, 117 insertions(+)

diff --git a/src/backend/access/heap/vacuumlazy.c b/src/backend/access/heap/vacuumlazy.c
index a23cdef..9358ab4 100644
--- a/src/backend/access/heap/vacuumlazy.c
+++ b/src/backend/access/heap/vacuumlazy.c
@@ -292,6 +292,14 @@ typedef struct LVRelStats
 	bool		lock_waiter_detected;
 } LVRelStats;
 
+typedef struct
+{
+	char 		*relnamespace;
+	char		*relname;
+	char 		*indname; /* undefined while not processing index */
+	BlockNumber blkno;	/* undefined while not processing heap */
+	int			phase;	/* Reusing same enums as for progress reporting */
+} vacuum_error_callback_arg;
 
 /* A few variables that don't seem worth passing around as parameters */
 static int	elevel = -1;
@@ -361,6 +369,7 @@ static void end_parallel_vacuum(Relation *Irel, IndexBulkDeleteResult **stats,
 								LVParallelState *lps, int nindexes);
 static LVSharedIndStats *get_indstats(LVShared *lvshared, int n);
 static bool skip_parallel_vacuum_index(Relation indrel, LVShared *lvshared);
+static void vacuum_error_callback(void *arg);

 /*
@@ -724,6 +733,8 @@ lazy_scan_heap(Relation onerel, VacuumParams *params, LVRelStats *vacrelstats,
 		PROGRESS_VACUUM_MAX_DEAD_TUPLES
 	};
 	int64		initprog_val[3];
+	ErrorContextCallback errcallback;
+	vacuum_error_callback_arg errcbarg;
 
 	pg_rusage_init(&ru0);
 
@@ -870,6 +881,17 @@ lazy_scan_heap(Relation onerel, VacuumParams *params, LVRelStats *vacrelstats,
 	else
 		skipping_blocks = false;
 
+	/* Setup error traceback support for ereport() */
+	errcbarg.relnamespace = get_namespace_name(RelationGetNamespace(onerel));
+	errcbarg.relname = relname;
+	errcbarg.blkno = InvalidBlockNumber; /* Not known yet */
+	errcbarg.phase = PROGRESS_VACUUM_PHASE_SCAN_HEAP;
+
+	errcallback.callback = vacuum_error_callback;
+	errcallback.arg = (void *) &errcbarg;
+	errcallback.previous = error_context_stack;
+	error_context_stack = &errcallback;
+
 	for (blkno = 0; blkno < nblocks; blkno++)
 	{
 		Buffer		buf;
@@ -891,6 +913,8 @@ lazy_scan_heap(Relation onerel, VacuumParams *params, LVRelStats *vacrelstats,
 #define FORCE_CHECK_PAGE() \
 		(blkno == nblocks - 1 && should_attempt_truncation(params, vacrelstats))
 
+		errcbarg.blkno = blkno;
+
 		pgstat_progress_update_param(PROGRESS_VACUUM_HEAP_BLKS_SCANNED, blkno);
 
 		if (blkno == next_unskippable_block)
@@ -987,6 +1011,9 @@ lazy_scan_heap(Relation onerel, VacuumParams *params, LVRelStats *vacrelstats,
 				vmbuffer = InvalidBuffer;
 			}
 
+			/* Pop the error context stack */
+			error_context_stack = errcallback.previous;
+
 			/* Work on all the indexes, then the heap */
 			lazy_vacuum_all_indexes(onerel, Irel, indstats,
 									vacrelstats, lps, nindexes);
@@ -1011,6 +1038,9 @@ lazy_scan_heap(Relation onerel, VacuumParams *params, LVRelStats *vacrelstats,
 			/* Report that we are once again scanning the heap */
 			pgstat_progress_update_param(PROGRESS_VACUUM_PHASE,
 										 PROGRESS_VACUUM_PHASE_SCAN_HEAP);
+
+			/* Set the error context while continuing heap scan */
+			error_context_stack = &errcallback;
 		}
 
 		/*
@@ -1597,6 +1627,9 @@ lazy_scan_heap(Relation onerel, VacuumParams *params, LVRelStats *vacrelstats,
 			RecordPageWithFreeSpace(onerel, blkno, freespace);
 	}
 
+	/* Pop the error context stack */
+	error_context_stack = errcallback.previous;
+
 	/* report that everything is scanned and vacuumed */
 	pgstat_progress_update_param(PROGRESS_VACUUM_HEAP_BLKS_SCANNED, blkno);
 
@@ -1772,11 +1805,26 @@ lazy_vacuum_heap(Relation onerel, LVRelStats *vacrelstats)
 	int			npages;
 	PGRUsage	ru0;
 	Buffer		vmbuffer = InvalidBuffer;
+	ErrorContextCallback errcallback;
+	vacuum_error_callback_arg errcbarg;
 
 	/* Report that we are now vacuuming the heap */
 	pgstat_progress_update_param(PROGRESS_VACUUM_PHASE,
 								 PROGRESS_VACUUM_PHASE_VACUUM_HEAP);
 
+	/*
+	 * Setup error traceback support for ereport()
+	 */
+	errcbarg.relnamespace = get_namespace_name(RelationGetNamespace(onerel));
+	errcbarg.relname = RelationGetRelationName(onerel);
+	errcbarg.blkno = InvalidBlockNumber; /* Not known yet */
+	errcbarg.phase = PROGRESS_VACUUM_PHASE_VACUUM_HEAP;
+
+	errcallback.callback = vacuum_error_callback;
+	errcallback.arg = (void *) &errcbarg;
+	errcallback.previous = error_context_stack;
+	error_context_stack = &errcallback;
+
 	pg_rusage_init(&ru0);
 	npages = 0;
 
@@ -1791,6 +1839,7 @@ lazy_vacuum_heap(Relation onerel, LVRelStats *vacrelstats)
 		vacuum_delay_point();
 
 		tblk = ItemPointerGetBlockNumber(&vacrelstats->dead_tuples->itemptrs[tupindex]);
+		errcbarg.blkno = tblk;
 		buf = ReadBufferExtended(onerel, MAIN_FORKNUM, tblk, RBM_NORMAL,
 								 vac_strategy);
 		if (!ConditionalLockBufferForCleanup(buf))
@@ -1811,6 +1860,9 @@ lazy_vacuum_heap(Relation onerel, LVRelStats *vacrelstats)
 		npages++;
 	}
 
+	/* Pop the error context stack */
+	error_context_stack = errcallback.previous;
+
 	if (BufferIsValid(vmbuffer))
 	{
 		ReleaseBuffer(vmbuffer);
@@ -2318,6 +2370,8 @@ lazy_vacuum_index(Relation indrel, IndexBulkDeleteResult **stats,
 	IndexVacuumInfo ivinfo;
 	const char *msg;
 	PGRUsage	ru0;
+	ErrorContextCallback errcallback;
+	vacuum_error_callback_arg errcbarg;
 
 	pg_rusage_init(&ru0);
 
@@ -2329,10 +2383,24 @@ lazy_vacuum_index(Relation indrel, IndexBulkDeleteResult **stats,
 	ivinfo.num_heap_tuples = reltuples;
 	ivinfo.strategy = vac_strategy;
 
+	/* Setup error traceback support for ereport() */
+	errcbarg.relnamespace = get_namespace_name(RelationGetNamespace(indrel));
+	errcbarg.indname = RelationGetRelationName(indrel);
+	errcbarg.relname = get_rel_name(indrel->rd_index->indexrelid);
+	errcbarg.phase = PROGRESS_VACUUM_PHASE_VACUUM_INDEX;
+
+	errcallback.callback = vacuum_error_callback;
+	errcallback.arg = (void *) &errcbarg;
+	errcallback.previous = error_context_stack;
+	error_context_stack = &errcallback;
+
 	/* Do bulk deletion */
 	*stats = index_bulk_delete(&ivinfo, *stats,
 							   lazy_tid_reaped, (void *) dead_tuples);
 
+	/* Pop the error context stack */
+	error_context_stack = errcallback.previous;
+
 	if (IsParallelWorker())
 		msg = gettext_noop("scanned index \"%s\" to remove %d row versions by parallel vacuum worker");
 	else
@@ -2359,6 +2427,8 @@ lazy_cleanup_index(Relation indrel,
 	IndexVacuumInfo ivinfo;
 	const char *msg;
 	PGRUsage	ru0;
+	vacuum_error_callback_arg errcbarg;
+	ErrorContextCallback errcallback;
 
 	pg_rusage_init(&ru0);
 
@@ -2371,8 +2441,22 @@ lazy_cleanup_index(Relation indrel,
 	ivinfo.num_heap_tuples = reltuples;
 	ivinfo.strategy = vac_strategy;
 
+	/* Setup error traceback support for ereport() */
+	errcbarg.relnamespace = get_namespace_name(RelationGetNamespace(indrel));
+	errcbarg.indname = RelationGetRelationName(indrel);
+	errcbarg.relname = get_rel_name(indrel->rd_index->indexrelid);
+	errcbarg.phase = PROGRESS_VACUUM_PHASE_INDEX_CLEANUP;
+
+	errcallback.previous = error_context_stack;
+	errcallback.callback = vacuum_error_callback;
+	errcallback.arg = (void *) &errcbarg;
+	error_context_stack = &errcallback;
+
 	*stats = index_vacuum_cleanup(&ivinfo, *stats);
 
+	/* Pop the error context stack */
+	error_context_stack = errcallback.previous;
+
 	if (!(*stats))
 		return;
 
@@ -3375,3 +3459,36 @@ parallel_vacuum_main(dsm_segment *seg, shm_toc *toc)
 	table_close(onerel, ShareUpdateExclusiveLock);
 	pfree(stats);
 }
+
+/*
+ * Error context callback for errors occurring during vacuum.
+ */
+static void
+vacuum_error_callback(void *arg)
+{
+	vacuum_error_callback_arg *cbarg = arg;
+
+	switch (cbarg->phase) {
+		case PROGRESS_VACUUM_PHASE_SCAN_HEAP:
+			if (BlockNumberIsValid(cbarg->blkno))
+				errcontext(_("while scanning block %u of relation \"%s.%s\""),
+						cbarg->blkno, cbarg->relnamespace, cbarg->relname);
+			break;
+
+		case PROGRESS_VACUUM_PHASE_VACUUM_HEAP:
+			if (BlockNumberIsValid(cbarg->blkno))
+				errcontext(_("while vacuuming block %u of relation \"%s.%s\""),
+						cbarg->blkno, cbarg->relnamespace, cbarg->relname);
+			break;
+
+		case PROGRESS_VACUUM_PHASE_VACUUM_INDEX:
+			errcontext(_("while vacuuming index \"%s.%s\" of relation \"%s\""),
+					cbarg->relnamespace, cbarg->indname, cbarg->relname);
+			break;
+
+		case PROGRESS_VACUUM_PHASE_INDEX_CLEANUP:
+			errcontext(_("while cleaning up index \"%s.%s\" of relation \"%s\""),
+					cbarg->relnamespace, cbarg->indname, cbarg->relname);
+			break;
+	}
+}
-- 
2.7.4

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Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v17-0002-Functions-to-initialize-errcontext.patch"