- The settings of some parameters determine the size of shared memory for
- tracking transaction IDs, locks, and prepared transactions. These shared
- memory structures should be no smaller on a standby than on the primary.
- Otherwise, it could happen that the standby runs out of shared memory
- during recovery. For example, if the primary uses a prepared transaction
- but the standby did not allocate any shared memory for tracking prepared
- transactions, then recovery will abort and cannot continue until the
- standby's configuration is changed. The parameters affected are:
+ The setting of some parameters on the standby will need reconfiguration
+ if they have been changed on the primary. For these parameters,
+ the value on the standby must
+ be equal to or greater than the value on the primary.
+ Therefore, if you want to increase these values, you should do so on all
+ standby servers first, before applying the changes to the primary server.
+ Conversely, if you want to decrease these values, you should do so on the
+ primary server first, before applying the changes to all standby servers.
+ If these parameters
+ are not set high enough then the standby will refuse to start.
+ Higher values can then be supplied and the server
+ restarted to begin recovery again. These parameters are:
-
- The easiest way to ensure this does not become a problem is to have these
- parameters set on the standbys to values equal to or greater than on the
- primary. Therefore, if you want to increase these values, you should do
- so on all standby servers first, before applying the changes to the
- primary server. Conversely, if you want to decrease these values, you
- should do so on the primary server first, before applying the changes to
- all standby servers. The WAL tracks changes to these parameters on the
- primary, and if a standby processes WAL that indicates that the current
- value on the primary is higher than its own value, it will log a warning, for example:
-
-WARNING: insufficient setting for parameter max_connections
-DETAIL: max_connections = 80 is a lower setting than on the master server (where its value was 100).
-HINT: Change parameters and restart the server, or there may be resource exhaustion errors sooner or later.
-
- Recovery will continue but could abort at any time thereafter. (It could
- also never end up failing if the activity on the primary does not actually
- require the full extent of the allocated shared memory resources.) If
- recovery reaches a point where it cannot continue due to lack of shared
- memory, recovery will pause and another warning will be logged, for example:
-
-WARNING: recovery paused because of insufficient parameter settings
-DETAIL: See earlier in the log about which settings are insufficient.
-HINT: Recovery cannot continue unless the configuration is changed and the server restarted.
-
- This warning will repeated once a minute. At that point, the settings on
- the standby need to be updated and the instance restarted before recovery
- can continue.
/* Get a free gxact from the freelist */
if (TwoPhaseState->freeGXacts == NULL)
- {
- StandbyParamErrorPauseRecovery();
ereport(ERROR,
(errcode(ERRCODE_OUT_OF_MEMORY),
errmsg("maximum number of prepared transactions reached"),
errhint("Increase max_prepared_transactions (currently %d).",
max_prepared_xacts)));
- }
gxact = TwoPhaseState->freeGXacts;
TwoPhaseState->freeGXacts = gxact->next;
static bool standby_signal_file_found = false;
static bool recovery_signal_file_found = false;
-static bool need_restart_for_parameter_values = false;
-
/* Was the last xlog file restored from archive, or local? */
static bool restoredFromArchive = false;
SpinLockRelease(&XLogCtl->info_lck);
}
-/*
- * If in hot standby, pause recovery because of a parameter conflict.
- *
- * Similar to recoveryPausesHere() but with a different messaging. The user
- * is expected to make the parameter change and restart the server. If they
- * just unpause recovery, they will then run into whatever error is after this
- * function call for the non-hot-standby case.
- *
- * We intentionally do not give advice about specific parameters or values
- * here because it might be misleading. For example, if we run out of lock
- * space, then in the single-server case we would recommend raising
- * max_locks_per_transaction, but in recovery it could equally be the case
- * that max_connections is out of sync with the primary. If we get here, we
- * have already logged any parameter discrepancies in
- * RecoveryRequiresIntParameter(), so users can go back to that and get
- * concrete and accurate information.
- */
-void
-StandbyParamErrorPauseRecovery(void)
-{
- TimestampTz last_warning = 0;
-
- if (!AmStartupProcess() || !need_restart_for_parameter_values)
- return;
-
- SetRecoveryPause(true);
-
- do
- {
- TimestampTz now = GetCurrentTimestamp();
-
- if (TimestampDifferenceExceeds(last_warning, now, 60000))
- {
- ereport(WARNING,
- (errmsg("recovery paused because of insufficient parameter settings"),
- errdetail("See earlier in the log about which settings are insufficient."),
- errhint("Recovery cannot continue unless the configuration is changed and the server restarted.")));
- last_warning = now;
- }
-
- pgstat_report_wait_start(WAIT_EVENT_RECOVERY_PAUSE);
- pg_usleep(1000000L); /* 1000 ms */
- pgstat_report_wait_end();
- HandleStartupProcInterrupts();
- }
- while (RecoveryIsPaused());
-}
-
/*
* When recovery_min_apply_delay is set, we wait long enough to make sure
* certain record types are applied at least that interval behind the master.
* Note that text field supplied is a parameter name and does not require
* translation
*/
-static void
-RecoveryRequiresIntParameter(const char *param_name, int currValue, int minValue)
-{
- if (currValue < minValue)
- {
- ereport(WARNING,
- (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
- errmsg("insufficient setting for parameter %s", param_name),
- errdetail("%s = %d is a lower setting than on the master server (where its value was %d).",
- param_name, currValue, minValue),
- errhint("Change parameters and restart the server, or there may be resource exhaustion errors sooner or later.")));
- need_restart_for_parameter_values = true;
- }
-}
+#define RecoveryRequiresIntParameter(param_name, currValue, minValue) \
+do { \
+ if ((currValue) < (minValue)) \
+ ereport(ERROR, \
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE), \
+ errmsg("hot standby is not possible because %s = %d is a lower setting than on the master server (its value was %d)", \
+ param_name, \
+ currValue, \
+ minValue))); \
+} while(0)
/*
* Check to see if required parameters are set high enough on this server
* If it still won't fit then we're out of memory
*/
if (head + nxids > pArray->maxKnownAssignedXids)
- {
- StandbyParamErrorPauseRecovery();
- ereport(ERROR,
- (errcode(ERRCODE_OUT_OF_MEMORY),
- errmsg("out of shared memory"),
- errdetail("There are no more KnownAssignedXids slots."),
- errhint("You might need to increase max_connections.")));
- }
+ elog(ERROR, "too many KnownAssignedXids");
}
/* Now we can insert the xids into the space starting at head */
if (locallockp)
*locallockp = NULL;
if (reportMemoryError)
- {
- StandbyParamErrorPauseRecovery();
ereport(ERROR,
(errcode(ERRCODE_OUT_OF_MEMORY),
errmsg("out of shared memory"),
errhint("You might need to increase max_locks_per_transaction.")));
- }
else
return LOCKACQUIRE_NOT_AVAIL;
}
if (locallockp)
*locallockp = NULL;
if (reportMemoryError)
- {
- StandbyParamErrorPauseRecovery();
ereport(ERROR,
(errcode(ERRCODE_OUT_OF_MEMORY),
errmsg("out of shared memory"),
errhint("You might need to increase max_locks_per_transaction.")));
- }
else
return LOCKACQUIRE_NOT_AVAIL;
}
{
LWLockRelease(partitionLock);
LWLockRelease(&MyProc->backendLock);
- StandbyParamErrorPauseRecovery();
ereport(ERROR,
(errcode(ERRCODE_OUT_OF_MEMORY),
errmsg("out of shared memory"),
if (!lock)
{
LWLockRelease(partitionLock);
- StandbyParamErrorPauseRecovery();
ereport(ERROR,
(errcode(ERRCODE_OUT_OF_MEMORY),
errmsg("out of shared memory"),
elog(PANIC, "lock table corrupted");
}
LWLockRelease(partitionLock);
- StandbyParamErrorPauseRecovery();
ereport(ERROR,
(errcode(ERRCODE_OUT_OF_MEMORY),
errmsg("out of shared memory"),
{
LWLockRelease(partitionLock);
LWLockRelease(&proc->backendLock);
- StandbyParamErrorPauseRecovery();
ereport(ERROR,
(errcode(ERRCODE_OUT_OF_MEMORY),
errmsg("out of shared memory"),
extern XLogRecPtr GetXLogWriteRecPtr(void);
extern bool RecoveryIsPaused(void);
extern void SetRecoveryPause(bool recoveryPause);
-extern void StandbyParamErrorPauseRecovery(void);
extern TimestampTz GetLatestXTime(void);
extern TimestampTz GetCurrentChunkReplayStartTime(void);
projects / postgresql.git / commitdiff