Hello, this is new version of standby checkpoint_segments patch.
- xlog.c: Make StandbyMode shared.
- checkpointer.c: Use IsStandbyMode() to check if postmaster is
under standby mode.
regards,
--
Kyotaro Horiguchi
NTT Open Source Software Center
== My e-mail address has been changed since Apr. 1, 2012.
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 8d0aabf..2457840 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -177,6 +177,12 @@ static bool LocalRecoveryInProgress = true;
static bool LocalHotStandbyActive = false;
/*
+ * Local copy of SharedIsStandbyMode variable. True actually means "not known,
+ * need to check the shared state".
+ */
+static bool LocalIsStandbyMode = true;
+
+/*
* Local state for XLogInsertAllowed():
* 1: unconditionally allowed to insert XLOG
* 0: unconditionally not allowed to insert XLOG
@@ -206,7 +212,6 @@ static TimestampTz recoveryTargetTime;
static char *recoveryTargetName;
/* options taken from recovery.conf for XLOG streaming */
-static bool StandbyMode = false;
static char *PrimaryConnInfo = NULL;
static char *TriggerFile = NULL;
@@ -427,6 +432,11 @@ typedef struct XLogCtlData
bool SharedHotStandbyActive;
/*
+ * SharedInStandbyMode indicates if we are running in standby mode.
+ */
+ bool SharedIsStandbyMode;
+
+ /*
* recoveryWakeupLatch is used to wake up the startup process to continue
* WAL replay, if it is waiting for WAL to arrive or failover trigger file
* to appear.
@@ -619,6 +629,7 @@ static void SetLatestXTime(TimestampTz xtime);
static void SetCurrentChunkStartTime(TimestampTz xtime);
static void CheckRequiredParameterValues(void);
static void XLogReportParameters(void);
+static void ExitStandbyMode(void);
static void LocalSetXLogInsertAllowed(void);
static void CheckPointGuts(XLogRecPtr checkPointRedo, int flags);
static void KeepLogSeg(XLogRecPtr recptr, uint32 *logId, uint32 *logSeg);
@@ -3115,7 +3126,7 @@ RestoreArchivedFile(char *path, const char *xlogfname,
* incorrectly conclude we've reached the end of WAL and we're
* done recovering ...
*/
- if (StandbyMode && stat_buf.st_size < expectedSize)
+ if (IsStandbyMode() && stat_buf.st_size < expectedSize)
elevel = DEBUG1;
else
elevel = FATAL;
@@ -4072,7 +4083,7 @@ next_record_is_invalid:
}
/* In standby-mode, keep trying */
- if (StandbyMode)
+ if (IsStandbyMode())
goto retry;
else
return NULL;
@@ -5098,6 +5109,7 @@ XLOGShmemInit(void)
XLogCtl->XLogCacheBlck = XLOGbuffers - 1;
XLogCtl->SharedRecoveryInProgress = true;
XLogCtl->SharedHotStandbyActive = false;
+ XLogCtl->SharedIsStandbyMode = true;
XLogCtl->Insert.currpage = (XLogPageHeader) (XLogCtl->pages);
SpinLockInit(&XLogCtl->info_lck);
InitSharedLatch(&XLogCtl->recoveryWakeupLatch);
@@ -5289,6 +5301,7 @@ readRecoveryCommandFile(void)
FILE *fd;
TimeLineID rtli = 0;
bool rtliGiven = false;
+ bool standby_mode = false;
ConfigVariable *item,
*head = NULL,
*tail = NULL;
@@ -5439,13 +5452,14 @@ readRecoveryCommandFile(void)
}
else if (strcmp(item->name, "standby_mode") == 0)
{
- if (!parse_bool(item->value, &StandbyMode))
+ if (!parse_bool(item->value, &standby_mode))
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("parameter \"%s\" requires a Boolean value",
"standby_mode")));
ereport(DEBUG2,
(errmsg_internal("standby_mode = '%s'", item->value)));
+
}
else if (strcmp(item->name, "primary_conninfo") == 0)
{
@@ -5470,7 +5484,7 @@ readRecoveryCommandFile(void)
/*
* Check for compulsory parameters
*/
- if (StandbyMode)
+ if (standby_mode)
{
if (PrimaryConnInfo == NULL && recoveryRestoreCommand == NULL)
ereport(WARNING,
@@ -5480,6 +5494,7 @@ readRecoveryCommandFile(void)
}
else
{
+ ExitStandbyMode();
if (recoveryRestoreCommand == NULL)
ereport(FATAL,
(errmsg("recovery command file \"%s\" must specify restore_command when standby mode is not enabled",
@@ -6086,7 +6101,7 @@ StartupXLOG(void)
if (InArchiveRecovery)
{
- if (StandbyMode)
+ if (IsStandbyMode())
ereport(LOG,
(errmsg("entering standby mode")));
else if (recoveryTarget == RECOVERY_TARGET_XID)
@@ -6110,7 +6125,7 @@ StartupXLOG(void)
* Take ownership of the wakeup latch if we're going to sleep during
* recovery.
*/
- if (StandbyMode)
+ if (IsStandbyMode())
OwnLatch(&XLogCtl->recoveryWakeupLatch);
if (read_backup_label(&checkPointLoc, &backupEndRequired,
@@ -6169,7 +6184,7 @@ StartupXLOG(void)
(errmsg("checkpoint record is at %X/%X",
checkPointLoc.xlogid, checkPointLoc.xrecoff)));
}
- else if (StandbyMode)
+ else if (IsStandbyMode())
{
/*
* The last valid checkpoint record required for a streaming
@@ -6683,7 +6698,7 @@ StartupXLOG(void)
* We don't need the latch anymore. It's not strictly necessary to disown
* it, but let's do it for the sake of tidiness.
*/
- if (StandbyMode)
+ if (IsStandbyMode())
DisownLatch(&XLogCtl->recoveryWakeupLatch);
/*
@@ -6691,7 +6706,7 @@ StartupXLOG(void)
* recovery to force fetching the files (which would be required at end of
* recovery, e.g., timeline history file) from archive or pg_xlog.
*/
- StandbyMode = false;
+ ExitStandbyMode();
/*
* Re-fetch the last valid or last applied record, so we can identify the
@@ -7096,7 +7111,7 @@ RecoveryInProgress(void)
* since normal backends won't ever be able to connect until this returns
* true. Postmaster knows this by way of signal, not via shared memory.
*
- * Unlike testing standbyState, this works in any process that's connected to
+ * Unlike testing InRecovery, this works in any process that's connected to
* shared memory.
*/
bool
@@ -7124,6 +7139,53 @@ HotStandbyActive(void)
}
/*
+ * Are we running in standby mode?
+ *
+ * Unlike testing InRecovery, this works in any process that's connected to
+ * shared memory.
+ */
+bool
+IsStandbyMode(void)
+{
+ /*
+ * We check shared state each time only until exiting standby mode. We
+ * can't re-enter standby mode, so there's no need to keep checking after
+ * the shared variable has once been seen false.
+ */
+ if (!LocalIsStandbyMode)
+ return false;
+ else
+ {
+ /* use volatile pointer to prevent code rearrangement */
+ volatile XLogCtlData *xlogctl = XLogCtl;
+
+ /* spinlock is essential on machines with weak memory ordering! */
+ SpinLockAcquire(&xlogctl->info_lck);
+ LocalIsStandbyMode = xlogctl->SharedIsStandbyMode;
+ SpinLockRelease(&xlogctl->info_lck);
+
+ return LocalIsStandbyMode;
+ }
+
+}
+
+
+/*
+ * Inform the processes connected to shared memory that we exit standby mode.
+ */
+static void
+ExitStandbyMode()
+{
+ /* use volatile pointer to prevent code rearrangement */
+ volatile XLogCtlData *xlogctl = XLogCtl;
+
+ /* spinlock is essential on machines with weak memory ordering! */
+ SpinLockAcquire(&xlogctl->info_lck);
+ LocalIsStandbyMode = xlogctl->SharedIsStandbyMode = false;
+ SpinLockRelease(&xlogctl->info_lck);
+}
+
+/*
* Is this process allowed to insert new WAL records?
*
* Ordinarily this is essentially equivalent to !RecoveryInProgress().
@@ -10026,7 +10088,7 @@ XLogPageRead(XLogRecPtr *RecPtr, int emode, bool fetching_ckpt,
* Request a restartpoint if we've replayed too much
* xlog since the last one.
*/
- if (StandbyMode && bgwriterLaunched)
+ if (IsStandbyMode() && bgwriterLaunched)
{
if (XLogCheckpointNeeded(readId, readSeg))
{
@@ -10048,7 +10110,7 @@ retry:
if (readFile < 0 ||
(readSource == XLOG_FROM_STREAM && !XLByteLT(*RecPtr, receivedUpto)))
{
- if (StandbyMode)
+ if (IsStandbyMode())
{
/*
* In standby mode, wait for the requested record to become
@@ -10362,7 +10424,7 @@ next_record_is_invalid:
readSource = 0;
/* In standby-mode, keep trying */
- if (StandbyMode)
+ if (IsStandbyMode())
goto retry;
else
return false;
diff --git a/src/backend/postmaster/checkpointer.c b/src/backend/postmaster/checkpointer.c
index c9473f7..f91bd52 100644
--- a/src/backend/postmaster/checkpointer.c
+++ b/src/backend/postmaster/checkpointer.c
@@ -491,8 +491,8 @@ CheckpointerMain(void)
* Initialize checkpointer-private variables used during checkpoint.
*/
ckpt_active = true;
- if (!do_restartpoint)
- ckpt_start_recptr = GetInsertRecPtr();
+ ckpt_start_recptr =
+ do_restartpoint ? GetXLogReplayRecPtr(NULL) : GetInsertRecPtr();
ckpt_start_time = now;
ckpt_cached_elapsed = 0;
@@ -715,6 +715,7 @@ IsCheckpointOnSchedule(double progress)
struct timeval now;
double elapsed_xlogs,
elapsed_time;
+ bool recovery_in_progress;
Assert(ckpt_active);
@@ -731,18 +732,27 @@ IsCheckpointOnSchedule(double progress)
return false;
/*
- * Check progress against WAL segments written and checkpoint_segments.
+ * Check progress against WAL segments written, or replayed for
+ * hot standby, and checkpoint_segments.
*
* We compare the current WAL insert location against the location
- * computed before calling CreateCheckPoint. The code in XLogInsert that
- * actually triggers a checkpoint when checkpoint_segments is exceeded
- * compares against RedoRecptr, so this is not completely accurate.
- * However, it's good enough for our purposes, we're only calculating an
- * estimate anyway.
+ * computed before calling CreateCheckPoint. The code in
+ * XLogInsert that actually triggers a checkpoint when
+ * checkpoint_segments is exceeded compares against RedoRecPtr.
+ * Similarly, we consult WAL replay location instead on hot
+ * standbys and XLogPageRead compares it aganst RedoRecPtr, too.
+ * Altough these are not completely accurate, it's good enough for
+ * our purposes, we're only calculating an estimate anyway.
+ */
+
+ /*
+ * Inhibit governing progress by segments in archive recovery.
*/
- if (!RecoveryInProgress())
+ recovery_in_progress = RecoveryInProgress();
+ if (!recovery_in_progress || IsStandbyMode())
{
- recptr = GetInsertRecPtr();
+ recptr = recovery_in_progress ? GetXLogReplayRecPtr(NULL) :
+ GetInsertRecPtr();
elapsed_xlogs =
(((double) (int32) (recptr.xlogid - ckpt_start_recptr.xlogid)) * XLogSegsPerFile +
((double) recptr.xrecoff - (double) ckpt_start_recptr.xrecoff) / XLogSegSize) /
diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h
index f8aecef..329119b 100644
--- a/src/include/access/xlog.h
+++ b/src/include/access/xlog.h
@@ -285,6 +285,7 @@ extern void issue_xlog_fsync(int fd, uint32 log, uint32 seg);
extern bool RecoveryInProgress(void);
extern bool HotStandbyActive(void);
+extern bool IsStandbyMode(void);
extern bool XLogInsertAllowed(void);
extern void GetXLogReceiptTime(TimestampTz *rtime, bool *fromStream);
extern XLogRecPtr GetXLogReplayRecPtr(XLogRecPtr *restoreLastRecPtr);
--
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