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help / color / mirror / Atom feedFrom: Kyotaro Horiguchi <[email protected]>
Subject: [PATCH v30 4/7] Make archiver process an auxiliary process
Date: Fri, 13 Mar 2020 16:59:38 +0900
This is a preliminary patch for shared-memory based stats collector.
Archiver process must be a auxiliary process since it uses shared
memory after stats data was moved into shared-memory. Make the process
an auxiliary process in order to make it work.
---
src/backend/access/transam/xlog.c | 46 +++++++++
src/backend/access/transam/xlogarchive.c | 2 +-
src/backend/bootstrap/bootstrap.c | 22 +++--
src/backend/postmaster/pgarch.c | 115 ++++-------------------
src/backend/postmaster/postmaster.c | 53 ++++++-----
src/include/access/xlog.h | 2 +
src/include/access/xlogarchive.h | 1 +
src/include/miscadmin.h | 2 +
src/include/postmaster/pgarch.h | 4 +-
src/include/storage/pmsignal.h | 1 -
10 files changed, 112 insertions(+), 136 deletions(-)
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 977d448f50..d75a257da2 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -684,6 +684,13 @@ typedef struct XLogCtlData
*/
Latch recoveryWakeupLatch;
+ /*
+ * archiverWakeupLatch is used to wake up the archiver process to process
+ * completed WAL segments, if it is waiting for WAL to arrive. Protected
+ * by info_lck.
+ */
+ Latch *archiverWakeupLatch;
+
/*
* During recovery, we keep a copy of the latest checkpoint record here.
* lastCheckPointRecPtr points to start of checkpoint record and
@@ -8450,6 +8457,45 @@ GetLastSegSwitchData(XLogRecPtr *lastSwitchLSN)
return result;
}
+/*
+ * XLogArchiveWakeupStart - Set up archiver wakeup stuff
+ */
+void
+XLogArchiveWakeupStart(void)
+{
+ SpinLockAcquire(&XLogCtl->info_lck);
+ Assert(XLogCtl->archiverWakeupLatch == NULL);
+ XLogCtl->archiverWakeupLatch = MyLatch;
+ SpinLockRelease(&XLogCtl->info_lck);
+}
+
+/*
+ * XLogArchiveWakeupEnd - Clean up archiver wakeup stuff
+ */
+void
+XLogArchiveWakeupEnd(void)
+{
+ SpinLockAcquire(&XLogCtl->info_lck);
+ XLogCtl->archiverWakeupLatch = NULL;
+ SpinLockRelease(&XLogCtl->info_lck);
+}
+
+/*
+ * XLogWakeupArchiver - Wake up archiver process
+ */
+void
+XLogArchiveWakeup(void)
+{
+ Latch *latch;
+
+ SpinLockAcquire(&XLogCtl->info_lck);
+ latch = XLogCtl->archiverWakeupLatch;
+ SpinLockRelease(&XLogCtl->info_lck);
+
+ if (latch)
+ SetLatch(latch);
+}
+
/*
* This must be called ONCE during postmaster or standalone-backend shutdown
*/
diff --git a/src/backend/access/transam/xlogarchive.c b/src/backend/access/transam/xlogarchive.c
index d62c12310a..d6c8bcce8b 100644
--- a/src/backend/access/transam/xlogarchive.c
+++ b/src/backend/access/transam/xlogarchive.c
@@ -490,7 +490,7 @@ XLogArchiveNotify(const char *xlog)
/* Notify archiver that it's got something to do */
if (IsUnderPostmaster)
- SendPostmasterSignal(PMSIGNAL_WAKEN_ARCHIVER);
+ XLogArchiveWakeup();
}
/*
diff --git a/src/backend/bootstrap/bootstrap.c b/src/backend/bootstrap/bootstrap.c
index 5480a024e0..d398ce6f03 100644
--- a/src/backend/bootstrap/bootstrap.c
+++ b/src/backend/bootstrap/bootstrap.c
@@ -319,6 +319,9 @@ AuxiliaryProcessMain(int argc, char *argv[])
case StartupProcess:
MyBackendType = B_STARTUP;
break;
+ case ArchiverProcess:
+ MyBackendType = B_ARCHIVER;
+ break;
case BgWriterProcess:
MyBackendType = B_BG_WRITER;
break;
@@ -439,30 +442,29 @@ AuxiliaryProcessMain(int argc, char *argv[])
proc_exit(1); /* should never return */
case StartupProcess:
- /* don't set signals, startup process has its own agenda */
StartupProcessMain();
- proc_exit(1); /* should never return */
+ proc_exit(1);
+
+ case ArchiverProcess:
+ PgArchiverMain();
+ proc_exit(1);
case BgWriterProcess:
- /* don't set signals, bgwriter has its own agenda */
BackgroundWriterMain();
- proc_exit(1); /* should never return */
+ proc_exit(1);
case CheckpointerProcess:
- /* don't set signals, checkpointer has its own agenda */
CheckpointerMain();
- proc_exit(1); /* should never return */
+ proc_exit(1);
case WalWriterProcess:
- /* don't set signals, walwriter has its own agenda */
InitXLOGAccess();
WalWriterMain();
- proc_exit(1); /* should never return */
+ proc_exit(1);
case WalReceiverProcess:
- /* don't set signals, walreceiver has its own agenda */
WalReceiverMain();
- proc_exit(1); /* should never return */
+ proc_exit(1);
default:
elog(PANIC, "unrecognized process type: %d", (int) MyAuxProcType);
diff --git a/src/backend/postmaster/pgarch.c b/src/backend/postmaster/pgarch.c
index 37be0e2bbb..7b66cb5613 100644
--- a/src/backend/postmaster/pgarch.c
+++ b/src/backend/postmaster/pgarch.c
@@ -48,6 +48,7 @@
#include "storage/latch.h"
#include "storage/pg_shmem.h"
#include "storage/pmsignal.h"
+#include "storage/procsignal.h"
#include "utils/guc.h"
#include "utils/ps_status.h"
@@ -78,7 +79,6 @@
* Local data
* ----------
*/
-static time_t last_pgarch_start_time;
static time_t last_sigterm_time = 0;
/*
@@ -95,8 +95,6 @@ static volatile sig_atomic_t ready_to_stop = false;
static pid_t pgarch_forkexec(void);
#endif
-NON_EXEC_STATIC void PgArchiverMain(int argc, char *argv[]) pg_attribute_noreturn();
-static void pgarch_waken(SIGNAL_ARGS);
static void pgarch_waken_stop(SIGNAL_ARGS);
static void pgarch_MainLoop(void);
static void pgarch_ArchiverCopyLoop(void);
@@ -110,75 +108,6 @@ static void pgarch_archiveDone(char *xlog);
* ------------------------------------------------------------
*/
-/*
- * pgarch_start
- *
- * Called from postmaster at startup or after an existing archiver
- * died. Attempt to fire up a fresh archiver process.
- *
- * Returns PID of child process, or 0 if fail.
- *
- * Note: if fail, we will be called again from the postmaster main loop.
- */
-int
-pgarch_start(void)
-{
- time_t curtime;
- pid_t pgArchPid;
-
- /*
- * Do nothing if no archiver needed
- */
- if (!XLogArchivingActive())
- return 0;
-
- /*
- * Do nothing if too soon since last archiver start. This is a safety
- * valve to protect against continuous respawn attempts if the archiver is
- * dying immediately at launch. Note that since we will be re-called from
- * the postmaster main loop, we will get another chance later.
- */
- curtime = time(NULL);
- if ((unsigned int) (curtime - last_pgarch_start_time) <
- (unsigned int) PGARCH_RESTART_INTERVAL)
- return 0;
- last_pgarch_start_time = curtime;
-
-#ifdef EXEC_BACKEND
- switch ((pgArchPid = pgarch_forkexec()))
-#else
- switch ((pgArchPid = fork_process()))
-#endif
- {
- case -1:
- ereport(LOG,
- (errmsg("could not fork archiver: %m")));
- return 0;
-
-#ifndef EXEC_BACKEND
- case 0:
- /* in postmaster child ... */
- InitPostmasterChild();
-
- /* Close the postmaster's sockets */
- ClosePostmasterPorts(false);
-
- /* Drop our connection to postmaster's shared memory, as well */
- dsm_detach_all();
- PGSharedMemoryDetach();
-
- PgArchiverMain(0, NULL);
- break;
-#endif
-
- default:
- return (int) pgArchPid;
- }
-
- /* shouldn't get here */
- return 0;
-}
-
/* ------------------------------------------------------------
* Local functions called by archiver follow
* ------------------------------------------------------------
@@ -212,14 +141,16 @@ pgarch_forkexec(void)
#endif /* EXEC_BACKEND */
-/*
- * PgArchiverMain
- *
- * The argc/argv parameters are valid only in EXEC_BACKEND case. However,
- * since we don't use 'em, it hardly matters...
- */
-NON_EXEC_STATIC void
-PgArchiverMain(int argc, char *argv[])
+/* Clean up notification stuff on exit */
+static void
+PgArchiverKill(int code, Datum arg)
+{
+ XLogArchiveWakeupEnd();
+}
+
+/* Main entry point for archiver process */
+void
+PgArchiverMain(void)
{
/*
* Ignore all signals usually bound to some action in the postmaster,
@@ -231,33 +162,23 @@ PgArchiverMain(int argc, char *argv[])
pqsignal(SIGQUIT, SignalHandlerForCrashExit);
pqsignal(SIGALRM, SIG_IGN);
pqsignal(SIGPIPE, SIG_IGN);
- pqsignal(SIGUSR1, pgarch_waken);
+ pqsignal(SIGUSR1, procsignal_sigusr1_handler);
pqsignal(SIGUSR2, pgarch_waken_stop);
+
/* Reset some signals that are accepted by postmaster but not here */
pqsignal(SIGCHLD, SIG_DFL);
+
+ /* Unblock signals (they were blocked when the postmaster forked us) */
PG_SETMASK(&UnBlockSig);
- MyBackendType = B_ARCHIVER;
- init_ps_display(NULL);
-
+ XLogArchiveWakeupStart();
+ on_shmem_exit(PgArchiverKill, 0);
+
pgarch_MainLoop();
exit(0);
}
-/* SIGUSR1 signal handler for archiver process */
-static void
-pgarch_waken(SIGNAL_ARGS)
-{
- int save_errno = errno;
-
- /* set flag that there is work to be done */
- wakened = true;
- SetLatch(MyLatch);
-
- errno = save_errno;
-}
-
/* SIGUSR2 signal handler for archiver process */
static void
pgarch_waken_stop(SIGNAL_ARGS)
diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index 73d278f3b2..a4b9d212a2 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -146,7 +146,8 @@
#define BACKEND_TYPE_AUTOVAC 0x0002 /* autovacuum worker process */
#define BACKEND_TYPE_WALSND 0x0004 /* walsender process */
#define BACKEND_TYPE_BGWORKER 0x0008 /* bgworker process */
-#define BACKEND_TYPE_ALL 0x000F /* OR of all the above */
+#define BACKEND_TYPE_ARCHIVER 0x0010 /* archiver process */
+#define BACKEND_TYPE_ALL 0x001F /* OR of all the above */
#define BACKEND_TYPE_WORKER (BACKEND_TYPE_AUTOVAC | BACKEND_TYPE_BGWORKER)
@@ -539,6 +540,7 @@ static void ShmemBackendArrayRemove(Backend *bn);
#endif /* EXEC_BACKEND */
#define StartupDataBase() StartChildProcess(StartupProcess)
+#define StartArchiver() StartChildProcess(ArchiverProcess)
#define StartBackgroundWriter() StartChildProcess(BgWriterProcess)
#define StartCheckpointer() StartChildProcess(CheckpointerProcess)
#define StartWalWriter() StartChildProcess(WalWriterProcess)
@@ -1785,7 +1787,7 @@ ServerLoop(void)
/* If we have lost the archiver, try to start a new one. */
if (PgArchPID == 0 && PgArchStartupAllowed())
- PgArchPID = pgarch_start();
+ PgArchPID = StartArchiver();
/* If we need to signal the autovacuum launcher, do so now */
if (avlauncher_needs_signal)
@@ -3055,7 +3057,7 @@ reaper(SIGNAL_ARGS)
if (!IsBinaryUpgrade && AutoVacuumingActive() && AutoVacPID == 0)
AutoVacPID = StartAutoVacLauncher();
if (PgArchStartupAllowed() && PgArchPID == 0)
- PgArchPID = pgarch_start();
+ PgArchPID = StartArchiver();
if (PgStatPID == 0)
PgStatPID = pgstat_start();
@@ -3190,20 +3192,16 @@ reaper(SIGNAL_ARGS)
}
/*
- * Was it the archiver? If so, just try to start a new one; no need
- * to force reset of the rest of the system. (If fail, we'll try
- * again in future cycles of the main loop.). Unless we were waiting
- * for it to shut down; don't restart it in that case, and
- * PostmasterStateMachine() will advance to the next shutdown step.
+ * Was it the archiver? Normal exit can be ignored; we'll start a new
+ * one at the next iteration of the postmaster's main loop, if
+ * necessary. Any other exit condition is treated as a crash.
*/
if (pid == PgArchPID)
{
PgArchPID = 0;
if (!EXIT_STATUS_0(exitstatus))
- LogChildExit(LOG, _("archiver process"),
- pid, exitstatus);
- if (PgArchStartupAllowed())
- PgArchPID = pgarch_start();
+ HandleChildCrash(pid, exitstatus,
+ _("archiver process"));
continue;
}
@@ -3451,7 +3449,7 @@ CleanupBackend(int pid,
/*
* HandleChildCrash -- cleanup after failed backend, bgwriter, checkpointer,
- * walwriter, autovacuum, or background worker.
+ * walwriter, autovacuum, archiver or background worker.
*
* The objectives here are to clean up our local state about the child
* process, and to signal all other remaining children to quickdie.
@@ -3656,6 +3654,18 @@ HandleChildCrash(int pid, int exitstatus, const char *procname)
signal_child(AutoVacPID, (SendStop ? SIGSTOP : SIGQUIT));
}
+ /* Take care of the archiver too */
+ if (pid == PgArchPID)
+ PgArchPID = 0;
+ else if (PgArchPID != 0 && take_action)
+ {
+ ereport(DEBUG2,
+ (errmsg_internal("sending %s to process %d",
+ (SendStop ? "SIGSTOP" : "SIGQUIT"),
+ (int) PgArchPID)));
+ signal_child(PgArchPID, (SendStop ? SIGSTOP : SIGQUIT));
+ }
+
/*
* Force a power-cycle of the pgarch process too. (This isn't absolutely
* necessary, but it seems like a good idea for robustness, and it
@@ -3928,6 +3938,7 @@ PostmasterStateMachine(void)
Assert(CheckpointerPID == 0);
Assert(WalWriterPID == 0);
Assert(AutoVacPID == 0);
+ Assert(PgArchPID == 0);
/* syslogger is not considered here */
pmState = PM_NO_CHILDREN;
}
@@ -5208,7 +5219,7 @@ sigusr1_handler(SIGNAL_ARGS)
*/
Assert(PgArchPID == 0);
if (XLogArchivingAlways())
- PgArchPID = pgarch_start();
+ PgArchPID = StartArchiver();
/*
* If we aren't planning to enter hot standby mode later, treat
@@ -5251,16 +5262,6 @@ sigusr1_handler(SIGNAL_ARGS)
if (StartWorkerNeeded || HaveCrashedWorker)
maybe_start_bgworkers();
- if (CheckPostmasterSignal(PMSIGNAL_WAKEN_ARCHIVER) &&
- PgArchPID != 0)
- {
- /*
- * Send SIGUSR1 to archiver process, to wake it up and begin archiving
- * next WAL file.
- */
- signal_child(PgArchPID, SIGUSR1);
- }
-
/* Tell syslogger to rotate logfile if requested */
if (SysLoggerPID != 0)
{
@@ -5493,6 +5494,10 @@ StartChildProcess(AuxProcType type)
ereport(LOG,
(errmsg("could not fork startup process: %m")));
break;
+ case ArchiverProcess:
+ ereport(LOG,
+ (errmsg("could not fork archiver process: %m")));
+ break;
case BgWriterProcess:
ereport(LOG,
(errmsg("could not fork background writer process: %m")));
diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h
index 9ec7b31cce..c0e149d526 100644
--- a/src/include/access/xlog.h
+++ b/src/include/access/xlog.h
@@ -313,6 +313,8 @@ extern XLogRecPtr GetRedoRecPtr(void);
extern XLogRecPtr GetInsertRecPtr(void);
extern XLogRecPtr GetFlushRecPtr(void);
extern XLogRecPtr GetLastImportantRecPtr(void);
+extern void XLogArchiveWakeupStart(void);
+extern void XLogArchiveWakeupEnd(void);
extern void RemovePromoteSignalFiles(void);
extern bool PromoteIsTriggered(void);
diff --git a/src/include/access/xlogarchive.h b/src/include/access/xlogarchive.h
index 1c67de2ede..54ce0b97d7 100644
--- a/src/include/access/xlogarchive.h
+++ b/src/include/access/xlogarchive.h
@@ -25,6 +25,7 @@ extern void ExecuteRecoveryCommand(const char *command, const char *commandName,
extern void KeepFileRestoredFromArchive(const char *path, const char *xlogfname);
extern void XLogArchiveNotify(const char *xlog);
extern void XLogArchiveNotifySeg(XLogSegNo segno);
+extern void XLogArchiveWakeup(void);
extern void XLogArchiveForceDone(const char *xlog);
extern bool XLogArchiveCheckDone(const char *xlog);
extern bool XLogArchiveIsBusy(const char *xlog);
diff --git a/src/include/miscadmin.h b/src/include/miscadmin.h
index 14fa127ab1..619b2f9c71 100644
--- a/src/include/miscadmin.h
+++ b/src/include/miscadmin.h
@@ -417,6 +417,7 @@ typedef enum
BootstrapProcess,
StartupProcess,
BgWriterProcess,
+ ArchiverProcess,
CheckpointerProcess,
WalWriterProcess,
WalReceiverProcess,
@@ -429,6 +430,7 @@ extern AuxProcType MyAuxProcType;
#define AmBootstrapProcess() (MyAuxProcType == BootstrapProcess)
#define AmStartupProcess() (MyAuxProcType == StartupProcess)
#define AmBackgroundWriterProcess() (MyAuxProcType == BgWriterProcess)
+#define AmArchiverProcess() (MyAuxProcType == ArchiverProcess)
#define AmCheckpointerProcess() (MyAuxProcType == CheckpointerProcess)
#define AmWalWriterProcess() (MyAuxProcType == WalWriterProcess)
#define AmWalReceiverProcess() (MyAuxProcType == WalReceiverProcess)
diff --git a/src/include/postmaster/pgarch.h b/src/include/postmaster/pgarch.h
index b3200874ca..e3ffc63f14 100644
--- a/src/include/postmaster/pgarch.h
+++ b/src/include/postmaster/pgarch.h
@@ -32,8 +32,6 @@
*/
extern int pgarch_start(void);
-#ifdef EXEC_BACKEND
-extern void PgArchiverMain(int argc, char *argv[]) pg_attribute_noreturn();
-#endif
+extern void PgArchiverMain(void) pg_attribute_noreturn();
#endif /* _PGARCH_H */
diff --git a/src/include/storage/pmsignal.h b/src/include/storage/pmsignal.h
index 56c5ec4481..c691acf8cd 100644
--- a/src/include/storage/pmsignal.h
+++ b/src/include/storage/pmsignal.h
@@ -34,7 +34,6 @@ typedef enum
{
PMSIGNAL_RECOVERY_STARTED, /* recovery has started */
PMSIGNAL_BEGIN_HOT_STANDBY, /* begin Hot Standby */
- PMSIGNAL_WAKEN_ARCHIVER, /* send a NOTIFY signal to xlog archiver */
PMSIGNAL_ROTATE_LOGFILE, /* send SIGUSR1 to syslogger to rotate logfile */
PMSIGNAL_START_AUTOVAC_LAUNCHER, /* start an autovacuum launcher */
PMSIGNAL_START_AUTOVAC_WORKER, /* start an autovacuum worker */
--
2.18.2
----Next_Part(Wed_Apr__1_17_37_23_2020_570)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v30-0005-Shared-memory-based-stats-collector.patch"
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