diff --git a/src/backend/access/transam/commit_ts.c b/src/backend/access/transam/commit_ts.c
index 78090c5f09c798866735b005fe77607b9545f883..79ca04a6eafd285d44e2db6e6d57fc6a54990ed0 100644
--- a/src/backend/access/transam/commit_ts.c
+++ b/src/backend/access/transam/commit_ts.c
@@ -93,6 +93,14 @@ CommitTimestampShared *commitTsShared;
/* GUC variable */
bool track_commit_timestamp;
+/*
+ * When this is set, commit_ts is force-enabled during recovery. This is so
+ * that a standby can replay WAL records coming from a master with the setting
+ * enabled. (Note that this doesn't enable SQL access to the data; it's
+ * effectively write-only until the GUC itself is enabled.)
+ */
+static bool enable_during_recovery;
+
static void SetXidCommitTsInPage(TransactionId xid, int nsubxids,
TransactionId *subxids, TimestampTz ts,
RepOriginId nodeid, int pageno);
@@ -100,6 +108,8 @@ static void TransactionIdSetCommitTs(TransactionId xid, TimestampTz ts,
RepOriginId nodeid, int slotno);
static int ZeroCommitTsPage(int pageno, bool writeXlog);
static bool CommitTsPagePrecedes(int page1, int page2);
+static void ActivateCommitTs(void);
+static void DeactivateCommitTs(bool do_wal);
static void WriteZeroPageXlogRec(int pageno);
static void WriteTruncateXlogRec(int pageno);
static void WriteSetTimestampXlogRec(TransactionId mainxid, int nsubxids,
@@ -122,10 +132,6 @@ static void WriteSetTimestampXlogRec(TransactionId mainxid, int nsubxids,
* subtrans implementation changes in the future, we might want to revisit the
* decision of storing timestamp info for each subxid.
*
- * The replaying_xlog parameter indicates whether the module should execute
- * its write even if the feature is nominally disabled, because we're replaying
- * a record generated from a master where the feature is enabled.
- *
* The write_xlog parameter tells us whether to include an XLog record of this
* or not. Normally, this is called from transaction commit routines (both
* normal and prepared) and the information will be stored in the transaction
@@ -136,18 +142,17 @@ static void WriteSetTimestampXlogRec(TransactionId mainxid, int nsubxids,
void
TransactionTreeSetCommitTsData(TransactionId xid, int nsubxids,
TransactionId *subxids, TimestampTz timestamp,
- RepOriginId nodeid,
- bool replaying_xlog, bool write_xlog)
+ RepOriginId nodeid, bool write_xlog)
{
int i;
TransactionId headxid;
TransactionId newestXact;
- /* We'd better not try to write xlog during replay */
- Assert(!(write_xlog && replaying_xlog));
-
- /* No-op if feature not enabled, unless replaying WAL */
- if (!track_commit_timestamp && !replaying_xlog)
+ /*
+ * No-op if the module is not enabled, but allow writes in a standby
+ * during recovery.
+ */
+ if (!track_commit_timestamp && !enable_during_recovery)
return;
/*
@@ -534,40 +539,61 @@ ZeroCommitTsPage(int pageno, bool writeXlog)
/*
* This must be called ONCE during postmaster or standalone-backend startup,
* after StartupXLOG has initialized ShmemVariableCache->nextXid.
+ *
+ * Caller may choose to enable the feature even when it is turned off in the
+ * configuration.
*/
void
-StartupCommitTs(void)
+StartupCommitTs(bool force_enable)
{
- TransactionId xid = ShmemVariableCache->nextXid;
- int pageno = TransactionIdToCTsPage(xid);
-
- if (track_commit_timestamp)
- {
- ActivateCommitTs();
- return;
- }
-
- LWLockAcquire(CommitTsControlLock, LW_EXCLUSIVE);
-
/*
- * Initialize our idea of the latest page number.
+ * If the module is not enabled, there's nothing to do here. The module
+ * could still be activated from elsewhere.
*/
- CommitTsCtl->shared->latest_page_number = pageno;
-
- LWLockRelease(CommitTsControlLock);
+ if (track_commit_timestamp || force_enable)
+ ActivateCommitTs();
}
/*
* This must be called ONCE during postmaster or standalone-backend startup,
- * when commit timestamp is enabled, after recovery has finished.
+ * after recovery has finished.
*/
void
CompleteCommitTsInitialization(void)
{
+ /*
+ * If the feature is not enabled, turn it off for good. This also removes
+ * any leftover data.
+ */
if (!track_commit_timestamp)
DeactivateCommitTs(true);
}
+/*
+ * Activate or deactivate CommitTs' upon reception of a XLOG_PARAMETER_CHANGE
+ * XLog record in a standby.
+ */
+void
+CommitTsParameterChange(bool newvalue, bool oldvalue)
+{
+ /*
+ * If the commit_ts module is disabled in this server and we get word from
+ * the master server that it is enabled there, activate it so that we can
+ * replay future WAL records involving it; also mark it as active on
+ * pg_control. If the old value was already set, we already did this, so
+ * don't do anything.
+ *
+ * If the module is disabled in the master, disable it here too.
+ */
+ if (newvalue)
+ {
+ if (!track_commit_timestamp && !oldvalue)
+ ActivateCommitTs();
+ }
+ else if (oldvalue)
+ DeactivateCommitTs(false);
+}
+
/*
* Activate this module whenever necessary.
* This must happen during postmaster or standalong-backend startup,
@@ -584,7 +610,7 @@ CompleteCommitTsInitialization(void)
* running with this module disabled for a while and thus might have skipped
* the normal creation point.
*/
-void
+static void
ActivateCommitTs(void)
{
TransactionId xid = ShmemVariableCache->nextXid;
@@ -629,6 +655,9 @@ ActivateCommitTs(void)
Assert(!CommitTsCtl->shared->page_dirty[slotno]);
LWLockRelease(CommitTsControlLock);
}
+
+ /* We can now replay xlog records from this module */
+ enable_during_recovery = true;
}
/*
@@ -641,7 +670,7 @@ ActivateCommitTs(void)
* Resets CommitTs into invalid state to make sure we don't hand back
* possibly-invalid data; also removes segments of old data.
*/
-void
+static void
DeactivateCommitTs(bool do_wal)
{
TransactionId xid = ShmemVariableCache->nextXid;
@@ -659,7 +688,18 @@ DeactivateCommitTs(bool do_wal)
ShmemVariableCache->newestCommitTs = InvalidTransactionId;
LWLockRelease(CommitTsLock);
- TruncateCommitTs(ReadNewTransactionId(), do_wal);
+ /*
+ * Remove *all* files. This is necessary so that there are no leftover
+ * files; in the case where this feature is later enabled after running
+ * with it disabled for some time there may be a gap in the file sequence.
+ * (We can probably tolerate out-of-sequence files, as they are going to
+ * be overwritten anyway when we wrap around, but it seems better to be
+ * tidy.)
+ */
+ (void) SlruScanDirectory(CommitTsCtl, SlruScanDirCbDeleteAll, NULL);
+
+ /* No longer enabled on recovery */
+ enable_during_recovery = false;
}
/*
@@ -699,7 +739,7 @@ ExtendCommitTs(TransactionId newestXact)
int pageno;
/* nothing to do if module not enabled */
- if (!track_commit_timestamp)
+ if (!track_commit_timestamp && !enable_during_recovery)
return;
/*
@@ -916,8 +956,7 @@ commit_ts_redo(XLogReaderState *record)
subxids = NULL;
TransactionTreeSetCommitTsData(setts->mainxid, nsubxids, subxids,
- setts->timestamp, setts->nodeid, false,
- true);
+ setts->timestamp, setts->nodeid, true);
if (subxids)
pfree(subxids);
}
diff --git a/src/backend/access/transam/twophase.c b/src/backend/access/transam/twophase.c
index e005cc558abdc719b6a1be18c807e7bdb7187e2d..8c47e0f707698de7253a39f6c2a2be9c7d5bcb55 100644
--- a/src/backend/access/transam/twophase.c
+++ b/src/backend/access/transam/twophase.c
@@ -2131,7 +2131,7 @@ RecordTransactionCommitPrepared(TransactionId xid,
TransactionTreeSetCommitTsData(xid, nchildren, children,
replorigin_session_origin_timestamp,
- replorigin_session_origin, false, false);
+ replorigin_session_origin, false);
/*
* We don't currently try to sleep before flush here ... nor is there any
diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 8f56a44d06e2c709f7180dcabcaa1a037f977cb3..e8aafbac508e72031d3bde24de0b4eba171cc7fb 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -1237,8 +1237,7 @@ RecordTransactionCommit(void)
TransactionTreeSetCommitTsData(xid, nchildren, children,
replorigin_session_origin_timestamp,
- replorigin_session_origin,
- false, false);
+ replorigin_session_origin, false);
}
/*
@@ -5333,8 +5332,7 @@ xact_redo_commit(xl_xact_parsed_commit *parsed,
/* Set the transaction commit timestamp and metadata */
TransactionTreeSetCommitTsData(xid, parsed->nsubxacts, parsed->subxacts,
- commit_time, origin_id,
- true, false);
+ commit_time, origin_id, false);
if (standbyState == STANDBY_DISABLED)
{
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 0266d61bbdb7b74eb4274d72cb8bf13d403f2fbe..08d16823ed105374023c405dcfd8afcb3bd83bcf 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -6567,7 +6567,7 @@ StartupXLOG(void)
* maintained during recovery and need not be started yet.
*/
StartupCLOG();
- StartupCommitTs();
+ StartupCommitTs(ControlFile->track_commit_timestamp);
StartupSUBTRANS(oldestActiveXID);
/*
@@ -7336,7 +7336,7 @@ StartupXLOG(void)
if (standbyState == STANDBY_DISABLED)
{
StartupCLOG();
- StartupCommitTs();
+ StartupCommitTs(false);
StartupSUBTRANS(oldestActiveXID);
}
@@ -9456,25 +9456,9 @@ xlog_redo(XLogReaderState *record)
ControlFile->minRecoveryPointTLI = ThisTimeLineID;
}
- /*
- * Update the commit timestamp tracking. If there was a change it
- * needs to be activated or deactivated accordingly.
- */
- if (track_commit_timestamp != xlrec.track_commit_timestamp)
- {
- track_commit_timestamp = xlrec.track_commit_timestamp;
- ControlFile->track_commit_timestamp = track_commit_timestamp;
- if (track_commit_timestamp)
- ActivateCommitTs();
- else
-
- /*
- * We can't create a new WAL record here, but that's OK as
- * master did the WAL logging already and we will replay the
- * record from master in case we crash.
- */
- DeactivateCommitTs(false);
- }
+ CommitTsParameterChange(xlrec.track_commit_timestamp,
+ ControlFile->track_commit_timestamp);
+ ControlFile->track_commit_timestamp = xlrec.track_commit_timestamp;
UpdateControlFile();
LWLockRelease(ControlFileLock);
diff --git a/src/include/access/commit_ts.h b/src/include/access/commit_ts.h
index dc865d1bc3d389acd095b9163eb8e27a62ef459a..1b95b5837ea31dcc6433d371a1fb39b384b374c2 100644
--- a/src/include/access/commit_ts.h
+++ b/src/include/access/commit_ts.h
@@ -24,8 +24,7 @@ extern bool check_track_commit_timestamp(bool *newval, void **extra,
extern void TransactionTreeSetCommitTsData(TransactionId xid, int nsubxids,
TransactionId *subxids, TimestampTz timestamp,
- RepOriginId nodeid,
- bool replaying_xlog, bool write_xlog);
+ RepOriginId nodeid, bool write_xlog);
extern bool TransactionIdGetCommitTsData(TransactionId xid,
TimestampTz *ts, RepOriginId *nodeid);
extern TransactionId GetLatestCommitTsData(TimestampTz *ts,
@@ -35,9 +34,8 @@ extern Size CommitTsShmemBuffers(void);
extern Size CommitTsShmemSize(void);
extern void CommitTsShmemInit(void);
extern void BootStrapCommitTs(void);
-extern void StartupCommitTs(void);
-extern void ActivateCommitTs(void);
-extern void DeactivateCommitTs(bool do_wal);
+extern void StartupCommitTs(bool force_enable);
+extern void CommitTsParameterChange(bool xlrecvalue, bool pgcontrolvalue);
extern void CompleteCommitTsInitialization(void);
extern void ShutdownCommitTs(void);
extern void CheckPointCommitTs(void);