From: Drouvot, Bertrand <bdrouvot@amazon.com>
To: Masahiko Sawada <masahiko.sawada@2ndquadrant.com>
To: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Cc: Alvaro Herrera <alvherre@alvh.no-ip.org>
Cc: PostgreSQL-development <pgsql-hackers@postgresql.org>
Subject: Re: Add Information during standby recovery conflicts
Date: Tue, 20 Oct 2020 14:58:10 +0200
Message-ID: <c51826fa-d9d4-4f99-d837-1872ce2d402a@amazon.com> (raw)
In-Reply-To: <CA+fd4k5JjcphpPw8oorRGAC5v4z-Bn-6dJ9=vRtX3O7gp+5YYg@mail.gmail.com>
References: <CA+fd4k4DTjgNXrgbQ7=2hVidG+inzqJUU2BziV=sL7yR0BmC=A@mail.gmail.com>
<20201015.121338.832998229451118046.horikyota.ntt@gmail.com>
<CA+fd4k53s4-P1PuebNgGysO8uHmiitKWxKXcFYgLU07iUx0AsQ@mail.gmail.com>
<20201015.145210.622238854316424234.horikyota.ntt@gmail.com>
<CA+fd4k5JjcphpPw8oorRGAC5v4z-Bn-6dJ9=vRtX3O7gp+5YYg@mail.gmail.com>
Hi,
On 10/15/20 9:15 AM, Masahiko Sawada wrote:
> CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you can confirm the sender and know the content is safe.
>
>
>
> On Thu, 15 Oct 2020 at 14:52, Kyotaro Horiguchi <horikyota.ntt@gmail.com> wrote:
>> At Thu, 15 Oct 2020 14:28:57 +0900, Masahiko Sawada <masahiko.sawada@2ndquadrant.com> wrote in
>>>> ereport(..(errmsg("%s", _("hogehoge")))) results in
>>>> fprintf((translated("%s")), translate("hogehoge")).
>>>>
>>>> So your change (errmsg("%s", gettext_noop("hogehoge")) results in
>>>>
>>>> fprintf((translated("%s")), DONT_translate("hogehoge")).
>>>>
>>>> which leads to a translation problem.
>>>>
>>>> (errmsg(gettext_noop("hogehoge"))
>>> This seems equivalent to (errmsg("hogehoge")), right?
>> Yes and no. However eventually the two works the same way,
>> "(errmsg(gettext_noop("hogehoge"))" is a shorthand of
>>
>> 1: char *msg = gettext_noop("hogehoge");
>> ...
>> 2: .. (errmsg(msg));
>>
>> That is, the line 1 only registers a message id "hogehoge" and doesn't
>> translate. The line 2 tries to translate the content of msg and it
>> finds the translation for the message id "hogehoge".
> Understood.
>
>>> I think I could understand translation stuff. Given we only report the
>>> const string returned from get_recovery_conflict_desc() without
>>> placeholders, the patch needs to use errmsg_internal() instead while
>>> not changing _() part. (errmsg(get_recovery_conflict_desc())) is not
>>> good (warned by -Wformat-security).
>> Ah, right. we get a complain if no value parameters added. We can
>> silence it by adding a dummy parameter to errmsg, but I'm not sure
>> which is preferable.
> Okay, I'm going to use errmsg_internal() for now until a better idea comes.
>
> I've attached the updated patch that fixed the translation part.
Thanks for reviewing and helping on this patch!
The patch tester bot is currently failing due to:
"proc.c:1290:5: error: ‘standbyWaitStart’ may be used uninitialized in
this function [-Werror=maybe-uninitialized]"
I've attached a new version with the minor change to fix it.
Bertrand
Attachments:v7-0002-Log-the-standby-recovery-conflict-waits.patch (text/plain, 14.2K) download
doc/src/sgml/config.sgml | 22 ++++
src/backend/storage/buffer/bufmgr.c | 13 +++
src/backend/storage/ipc/standby.c | 150 ++++++++++++++++++++++----
src/backend/storage/lmgr/proc.c | 26 +++++
src/backend/utils/misc/guc.c | 10 +-
src/backend/utils/misc/postgresql.conf.sample | 2 +
src/include/storage/procsignal.h | 1 +
src/include/storage/standby.h | 2 +
8 files changed, 205 insertions(+), 21 deletions(-)
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgmlindex ee914740cc..a4a43dff83 100644--- a/doc/src/sgml/config.sgml+++ b/doc/src/sgml/config.sgml@@ -6839,6 +6839,28 @@ log_line_prefix = '%m [%p] %q%u@%d/%a '
</listitem>
</varlistentry>
+ <varlistentry id="guc-log-recovery-conflict-waits" xreflabel="log_recovery_conflict_waits">+ <term><varname>log_recovery_conflict_waits</varname> (<type>boolean</type>)+ <indexterm>+ <primary><varname>log_recovery_conflict_waits</varname> configuration parameter</primary>+ </indexterm>+ </term>+ <listitem>+ <para>+ Controls whether a log message is produced when the startup process+ is waiting for recovery conflicts longer than+ <varname>deadlock_timeout</varname>. This is useful in determining if+ recovery conflicts prevents the recovery from applying WAL.+ </para>++ <para>+ This parameter can only be set in the <filename>postgresql.conf</filename>+ file or on the server command line.+ The default is <literal>off</literal>.+ </para>+ </listitem>+ </varlistentry>+
<varlistentry id="guc-log-parameter-max-length" xreflabel="log_parameter_max_length">
<term><varname>log_parameter_max_length</varname> (<type>integer</type>)
<indexterm>
diff --git a/src/backend/storage/buffer/bufmgr.c b/src/backend/storage/buffer/bufmgr.cindex e549fa1d30..648ced33eb 100644--- a/src/backend/storage/buffer/bufmgr.c+++ b/src/backend/storage/buffer/bufmgr.c@@ -3808,6 +3808,8 @@ LockBufferForCleanup(Buffer buffer)
{
BufferDesc *bufHdr;
char *new_status = NULL;
+ TimestampTz waitStart = 0;+ bool logged_recovery_conflict = false;
Assert(BufferIsPinned(buffer));
Assert(PinCountWaitBuf == NULL);
@@ -3829,6 +3831,9 @@ LockBufferForCleanup(Buffer buffer)
bufHdr = GetBufferDescriptor(buffer - 1);
+ if (log_recovery_conflict_waits)+ waitStart = GetCurrentTimestamp();+
for (;;)
{
uint32 buf_state;
@@ -3881,6 +3886,14 @@ LockBufferForCleanup(Buffer buffer)
new_status[len] = '\0'; /* truncate off " waiting" */
}
+ if (log_recovery_conflict_waits && !logged_recovery_conflict &&+ TimestampDifferenceExceeds(waitStart, GetCurrentTimestamp(),+ DeadlockTimeout))+ {+ LogRecoveryConflict(PROCSIG_RECOVERY_CONFLICT_BUFFERPIN, NULL);+ logged_recovery_conflict = true;+ }+
/* Publish the bufid that Startup process waits on */
SetStartupBufferPinWaitBufId(buffer - 1);
/* Set alarm and then wait to be signaled by UnpinBuffer() */
diff --git a/src/backend/storage/ipc/standby.c b/src/backend/storage/ipc/standby.cindex 52b2809dac..5820713566 100644--- a/src/backend/storage/ipc/standby.c+++ b/src/backend/storage/ipc/standby.c@@ -39,6 +39,7 @@
int vacuum_defer_cleanup_age;
int max_standby_archive_delay = 30 * 1000;
int max_standby_streaming_delay = 30 * 1000;
+bool log_recovery_conflict_waits = false;
static HTAB *RecoveryLockLists;
@@ -49,6 +50,7 @@ static void ResolveRecoveryConflictWithVirtualXIDs(VirtualTransactionId *waitlis
static void SendRecoveryConflictWithBufferPin(ProcSignalReason reason);
static XLogRecPtr LogCurrentRunningXacts(RunningTransactions CurrRunningXacts);
static void LogAccessExclusiveLocks(int nlocks, xl_standby_lock *locks);
+static const char *get_recovery_conflict_desc(ProcSignalReason reason);
/*
* Keep track of all the locks owned by a given transaction.
@@ -215,15 +217,60 @@ WaitExceedsMaxStandbyDelay(uint32 wait_event_info)
return false;
}
+/*+ * Log the recovery conflict.+ *+ * This function also reports the details about the conflicting process ids+ * if *waitlist is not NULL.+ */+void+LogRecoveryConflict(ProcSignalReason reason, VirtualTransactionId *waitlist)+{+ if (waitlist)+ {+ VirtualTransactionId *vxids;+ StringInfoData buf;+ int nprocs = 0;++ initStringInfo(&buf);++ /* construct a string of list of the conflicted virtual transactions */+ vxids = waitlist;+ while (VirtualTransactionIdIsValid(*vxids))+ {+ PGPROC *proc = BackendIdGetProc(vxids->backendId);++ if (nprocs == 0)+ appendStringInfo(&buf, "%d", proc->pid);+ else+ appendStringInfo(&buf, ", %d", proc->pid);++ nprocs++;+ vxids++;+ }++ ereport(LOG,+ (errmsg_internal("%s", get_recovery_conflict_desc(reason)),+ (errdetail_log_plural("Conflicting process: %s.",+ "Conflicting processes: %s.",+ nprocs, buf.data))));+ pfree(buf.data);+ }+ else+ ereport(LOG,+ (errmsg_internal("%s", get_recovery_conflict_desc(reason))));+}+
/*
* This is the main executioner for any query backend that conflicts with
* recovery processing. Judgement has already been passed on it within
* a specific rmgr. Here we just issue the orders to the procs. The procs
* then throw the required error as instructed.
*
- * If report_waiting is true, "waiting" is reported in PS display if necessary.- * If the caller has already reported that, report_waiting should be false.- * Otherwise, "waiting" is reported twice unexpectedly.+ * If report_waiting is true, "waiting" is reported in PS display and log+ * the waits for the recovery conflict if necessary. If the caller has already+ * reported that, report_waiting should be false. Otherwise, both are reported+ * twice unexpectedly.
*/
static void
ResolveRecoveryConflictWithVirtualXIDs(VirtualTransactionId *waitlist,
@@ -232,6 +279,7 @@ ResolveRecoveryConflictWithVirtualXIDs(VirtualTransactionId *waitlist,
{
TimestampTz waitStart = 0;
char *new_status;
+ bool logged = false;
/* Fast exit, to avoid a kernel call if there's no work to be done. */
if (!VirtualTransactionIdIsValid(*waitlist))
@@ -249,13 +297,25 @@ ResolveRecoveryConflictWithVirtualXIDs(VirtualTransactionId *waitlist,
/* wait until the virtual xid is gone */
while (!VirtualXactLock(*waitlist, false))
{
+ TimestampTz ts;++ if (report_waiting)+ ts = GetCurrentTimestamp();++ /* Log the recovery conflict */+ if (log_recovery_conflict_waits && !logged && report_waiting &&+ TimestampDifferenceExceeds(waitStart, ts, DeadlockTimeout))+ {+ LogRecoveryConflict(reason, waitlist);+ logged = true;+ }+
/*
* Report via ps if we have been waiting for more than 500 msec
* (should that be configurable?)
*/
if (update_process_title && new_status == NULL && report_waiting &&
- TimestampDifferenceExceeds(waitStart, GetCurrentTimestamp(),- 500))+ TimestampDifferenceExceeds(waitStart, ts, 500))
{
const char *old_status;
int len;
@@ -408,7 +468,35 @@ ResolveRecoveryConflictWithLock(LOCKTAG locktag)
ltime = GetStandbyLimitTime();
- if (GetCurrentTimestamp() >= ltime)+ if (ltime == 0 || GetCurrentTimestamp() < ltime)+ {+ EnableTimeoutParams timeouts[2];+ int cnt = 0;++ /*+ * Wait (or wait again) until ltime+ */+ if (ltime != 0)+ {+ timeouts[cnt].id = STANDBY_LOCK_TIMEOUT;+ timeouts[cnt].type = TMPARAM_AT;+ timeouts[cnt].fin_time = ltime;+ cnt++;+ }++ /* Also, set deadlock timeout for logging purpose if necessary */+ if (log_recovery_conflict_waits)+ {+ timeouts[cnt].id = STANDBY_TIMEOUT;+ timeouts[cnt].type = TMPARAM_AFTER;+ timeouts[cnt].delay_ms = DeadlockTimeout;+ cnt++;+ }++ if (cnt > 0)+ enable_timeouts(timeouts, cnt);+ }+ else
{
/*
* We're already behind, so clear a path as quickly as possible.
@@ -419,26 +507,15 @@ ResolveRecoveryConflictWithLock(LOCKTAG locktag)
/*
* Prevent ResolveRecoveryConflictWithVirtualXIDs() from reporting
- * "waiting" in PS display by disabling its argument report_waiting- * because the caller, WaitOnLock(), has already reported that.+ * "waiting" in PS display and logging recovery conflict by disabling+ * its argument report_waiting because the callers have already reported+ * that.
*/
ResolveRecoveryConflictWithVirtualXIDs(backends,
PROCSIG_RECOVERY_CONFLICT_LOCK,
PG_WAIT_LOCK | locktag.locktag_type,
false);
}
- else- {- /*- * Wait (or wait again) until ltime- */- EnableTimeoutParams timeouts[1];-- timeouts[0].id = STANDBY_LOCK_TIMEOUT;- timeouts[0].type = TMPARAM_AT;- timeouts[0].fin_time = ltime;- enable_timeouts(timeouts, 1);- }
/* Wait to be signaled by the release of the Relation Lock */
ProcWaitForSignal(PG_WAIT_LOCK | locktag.locktag_type);
@@ -1116,3 +1193,36 @@ LogStandbyInvalidations(int nmsgs, SharedInvalidationMessage *msgs,
nmsgs * sizeof(SharedInvalidationMessage));
XLogInsert(RM_STANDBY_ID, XLOG_INVALIDATIONS);
}
++/* Return the description of recovery conflict */+static const char *+get_recovery_conflict_desc(ProcSignalReason reason)+{+ const char *reasonDesc = _("unknown reason");++ switch (reason)+ {+ case PROCSIG_RECOVERY_CONFLICT_BUFFERPIN:+ reasonDesc = _("recovery is waiting recovery conflict on buffer pin");+ break;+ case PROCSIG_RECOVERY_CONFLICT_LOCK:+ reasonDesc = _("recovery is waiting recovery conflict on lock");+ break;+ case PROCSIG_RECOVERY_CONFLICT_TABLESPACE:+ reasonDesc = _("recovery is waiting recovery conflict on tablespace");+ break;+ case PROCSIG_RECOVERY_CONFLICT_SNAPSHOT:+ reasonDesc = _("recovery is waiting recovery conflict on snapshot");+ break;+ case PROCSIG_RECOVERY_CONFLICT_STARTUP_DEADLOCK:+ reasonDesc = _("recovery is waiting recovery conflict on buffer deadlock");+ break;+ case PROCSIG_RECOVERY_CONFLICT_DATABASE:+ reasonDesc = _("recovery is waiting recovery conflict on database");+ break;+ default:+ break;+ }++ return reasonDesc;+}diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.cindex 88566bd9fa..a81cab34a4 100644--- a/src/backend/storage/lmgr/proc.c+++ b/src/backend/storage/lmgr/proc.c@@ -1068,7 +1068,9 @@ ProcSleep(LOCALLOCK *locallock, LockMethod lockMethodTable)
ProcWaitStatus myWaitStatus;
PGPROC *proc;
PGPROC *leader = MyProc->lockGroupLeader;
+ TimestampTz standbyWaitStart = 0;
int i;
+ bool logged_recovery_conflict = false;
/*
* If group locking is in use, locks held by members of my locking group
@@ -1260,6 +1262,8 @@ ProcSleep(LOCALLOCK *locallock, LockMethod lockMethodTable)
else
enable_timeout_after(DEADLOCK_TIMEOUT, DeadlockTimeout);
}
+ else+ standbyWaitStart = GetCurrentTimestamp();
/*
* If somebody wakes us between LWLockRelease and WaitLatch, the latch
@@ -1281,6 +1285,28 @@ ProcSleep(LOCALLOCK *locallock, LockMethod lockMethodTable)
{
/* Set a timer and wait for that or for the Lock to be granted */
ResolveRecoveryConflictWithLock(locallock->tag.lock);
++ if (log_recovery_conflict_waits && !logged_recovery_conflict &&+ TimestampDifferenceExceeds(standbyWaitStart, GetCurrentTimestamp(),+ DeadlockTimeout))+ {+ VirtualTransactionId *vxids;+ int cnt;++ vxids = GetLockConflicts(&locallock->tag.lock,+ AccessExclusiveLock, &cnt);++ /*+ * Log the recovery conflict if there are still virtual transactions+ * conflicting on the lock.+ */+ if (cnt > 0)+ {+ LogRecoveryConflict(PROCSIG_RECOVERY_CONFLICT_LOCK,+ vxids);+ logged_recovery_conflict = true;+ }+ }
}
else
{
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.cindex 596bcb7b84..e55a28b1cd 100644--- a/src/backend/utils/misc/guc.c+++ b/src/backend/utils/misc/guc.c@@ -1570,7 +1570,15 @@ static struct config_bool ConfigureNamesBool[] =
false,
NULL, NULL, NULL
},
-+ {+ {"log_recovery_conflict_waits", PGC_SIGHUP, LOGGING_WHAT,+ gettext_noop("Logs standby recovery conflict waits."),+ NULL+ },+ &log_recovery_conflict_waits,+ false,+ NULL, NULL, NULL+ },
{
{"log_hostname", PGC_SIGHUP, LOGGING_WHAT,
gettext_noop("Logs the host name in the connection logs."),
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sampleindex 9cb571f7cc..5625681e8a 100644--- a/src/backend/utils/misc/postgresql.conf.sample+++ b/src/backend/utils/misc/postgresql.conf.sample@@ -553,6 +553,8 @@
# %% = '%'
# e.g. '<%u%%%d> '
#log_lock_waits = off # log lock waits >= deadlock_timeout
+#log_recovery_conflict_waits = off # log standby recovery conflict waits+ # >= deadlock_timeout
#log_parameter_max_length = -1 # when logging statements, limit logged
# bind-parameter values to N bytes;
# -1 means print in full, 0 disables
diff --git a/src/include/storage/procsignal.h b/src/include/storage/procsignal.hindex 5cb39697f3..7cd988263d 100644--- a/src/include/storage/procsignal.h+++ b/src/include/storage/procsignal.h@@ -71,5 +71,6 @@ extern void WaitForProcSignalBarrier(uint64 generation);
extern void ProcessProcSignalBarrier(void);
extern void procsignal_sigusr1_handler(SIGNAL_ARGS);
+extern const char *get_procsignal_reason_desc(ProcSignalReason reason);
#endif /* PROCSIGNAL_H */
diff --git a/src/include/storage/standby.h b/src/include/storage/standby.hindex faaf1d3817..642ce5201a 100644--- a/src/include/storage/standby.h+++ b/src/include/storage/standby.h@@ -23,6 +23,7 @@
extern int vacuum_defer_cleanup_age;
extern int max_standby_archive_delay;
extern int max_standby_streaming_delay;
+extern bool log_recovery_conflict_waits;
extern void InitRecoveryTransactionEnvironment(void);
extern void ShutdownRecoveryTransactionEnvironment(void);
@@ -38,6 +39,7 @@ extern void CheckRecoveryConflictDeadlock(void);
extern void StandbyDeadLockHandler(void);
extern void StandbyTimeoutHandler(void);
extern void StandbyLockTimeoutHandler(void);
+extern void LogRecoveryConflict(ProcSignalReason reason, VirtualTransactionId *waitlist);
/*
* Standby Rmgr (RM_STANDBY_ID)
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To: pgsql-hackers@postgresql.org
Cc: bdrouvot@amazon.com, masahiko.sawada@2ndquadrant.com, horikyota.ntt@gmail.com, alvherre@alvh.no-ip.org
Subject: Re: Add Information during standby recovery conflicts
In-Reply-To: <c51826fa-d9d4-4f99-d837-1872ce2d402a@amazon.com>
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