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* [PATCH v55 3/3] Make archiver process an auxiliary process
@ 2021-03-11 09:01 Kyotaro Horiguchi <[email protected]>
0 siblings, 0 replies; 4+ messages in thread
From: Kyotaro Horiguchi @ 2021-03-11 09:01 UTC (permalink / raw)
This makes it possible to archiver process uses ipc functions and let
us monitor archiver process status.
---
doc/src/sgml/monitoring.sgml | 1 +
src/backend/access/transam/xlogarchive.c | 4 +-
src/backend/bootstrap/bootstrap.c | 22 ++-
src/backend/postmaster/pgarch.c | 240 ++++++++++-------------
src/backend/postmaster/postmaster.c | 81 ++++----
src/backend/storage/ipc/ipci.c | 2 +
src/include/miscadmin.h | 2 +
src/include/postmaster/pgarch.h | 14 +-
src/include/storage/pmsignal.h | 1 -
src/include/storage/proc.h | 8 +-
src/tools/pgindent/typedefs.list | 1 +
11 files changed, 164 insertions(+), 212 deletions(-)
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index 1ba813bbb9..a96455bdb2 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -935,6 +935,7 @@ postgres 27093 0.0 0.0 30096 2752 ? Ss 11:34 0:00 postgres: ser
<literal>logical replication worker</literal>,
<literal>parallel worker</literal>, <literal>background writer</literal>,
<literal>client backend</literal>, <literal>checkpointer</literal>,
+ <literal>archiver</literal>,
<literal>startup</literal>, <literal>walreceiver</literal>,
<literal>walsender</literal> and <literal>walwriter</literal>.
In addition, background workers registered by extensions may have
diff --git a/src/backend/access/transam/xlogarchive.c b/src/backend/access/transam/xlogarchive.c
index 1c5a4f8b5a..26b023e754 100644
--- a/src/backend/access/transam/xlogarchive.c
+++ b/src/backend/access/transam/xlogarchive.c
@@ -25,11 +25,11 @@
#include "common/archive.h"
#include "miscadmin.h"
#include "postmaster/startup.h"
+#include "postmaster/pgarch.h"
#include "replication/walsender.h"
#include "storage/fd.h"
#include "storage/ipc.h"
#include "storage/lwlock.h"
-#include "storage/pmsignal.h"
/*
* Attempt to retrieve the specified file from off-line archival storage.
@@ -491,7 +491,7 @@ XLogArchiveNotify(const char *xlog)
/* Notify archiver that it's got something to do */
if (IsUnderPostmaster)
- SendPostmasterSignal(PMSIGNAL_WAKEN_ARCHIVER);
+ PgArchWakeup();
}
/*
diff --git a/src/backend/bootstrap/bootstrap.c b/src/backend/bootstrap/bootstrap.c
index 6f615e6622..41da0c5059 100644
--- a/src/backend/bootstrap/bootstrap.c
+++ b/src/backend/bootstrap/bootstrap.c
@@ -317,6 +317,9 @@ AuxiliaryProcessMain(int argc, char *argv[])
case StartupProcess:
MyBackendType = B_STARTUP;
break;
+ case ArchiverProcess:
+ MyBackendType = B_ARCHIVER;
+ break;
case BgWriterProcess:
MyBackendType = B_BG_WRITER;
break;
@@ -437,30 +440,29 @@ 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 edec311f12..07ba989a37 100644
--- a/src/backend/postmaster/pgarch.c
+++ b/src/backend/postmaster/pgarch.c
@@ -38,16 +38,14 @@
#include "libpq/pqsignal.h"
#include "miscadmin.h"
#include "pgstat.h"
-#include "postmaster/fork_process.h"
#include "postmaster/interrupt.h"
#include "postmaster/pgarch.h"
-#include "postmaster/postmaster.h"
-#include "storage/dsm.h"
#include "storage/fd.h"
#include "storage/ipc.h"
#include "storage/latch.h"
-#include "storage/pg_shmem.h"
#include "storage/pmsignal.h"
+#include "storage/procsignal.h"
+#include "storage/spin.h"
#include "utils/guc.h"
#include "utils/ps_status.h"
@@ -73,153 +71,101 @@
*/
#define NUM_ORPHAN_CLEANUP_RETRIES 3
+/* Shared memory area for archiver process */
+typedef struct PgArchData
+{
+ int pgprocno; /* pgprocno of archiver process */
+} PgArchData;
+
/* ----------
* Local data
* ----------
*/
-static time_t last_pgarch_start_time;
static time_t last_sigterm_time = 0;
+static PgArchData *PgArch = NULL;
/*
* Flags set by interrupt handlers for later service in the main loop.
*/
-static volatile sig_atomic_t wakened = false;
static volatile sig_atomic_t ready_to_stop = false;
/* ----------
* Local function forward declarations
* ----------
*/
-#ifdef EXEC_BACKEND
-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);
static bool pgarch_archiveXlog(char *xlog);
static bool pgarch_readyXlog(char *xlog);
static void pgarch_archiveDone(char *xlog);
+static void pgarch_die(int code, Datum arg);
-
-/* ------------------------------------------------------------
- * Public functions called from postmaster follow
- * ------------------------------------------------------------
- */
-
-/*
- * 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)
+/* Report shared memory space needed by PgArchShmemInit */
+Size
+PgArchShmemSize(void)
{
- time_t curtime;
- pid_t pgArchPid;
+ Size size = 0;
- /*
- * 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;
+ size = add_size(size, sizeof(PgArchData));
-#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);
+ return size;
+}
- /* Drop our connection to postmaster's shared memory, as well */
- dsm_detach_all();
- PGSharedMemoryDetach();
+/* Allocate and initialize archiver-related shared memory */
+void
+PgArchShmemInit(void)
+{
+ bool found;
- PgArchiverMain(0, NULL);
- break;
-#endif
+ PgArch = (PgArchData *)
+ ShmemInitStruct("Archiver Data", PgArchShmemSize(), &found);
- default:
- return (int) pgArchPid;
+ if (!found)
+ {
+ /* First time through, so initialize */
+ MemSet(PgArch, 0, PgArchShmemSize());
+ PgArch->pgprocno = INVALID_PGPROCNO;
}
-
- /* shouldn't get here */
- return 0;
}
-/* ------------------------------------------------------------
- * Local functions called by archiver follow
- * ------------------------------------------------------------
- */
-
-
-#ifdef EXEC_BACKEND
-
/*
- * pgarch_forkexec() -
+ * PgArchIsSuppressed
*
- * Format up the arglist for, then fork and exec, archive process
+ * Return true if archiver relaunch is suppressed.
+ *
+ * This is a safety valve to protect against continuous respawn attempts if the
+ * archiver is dying immediately at launch. Note that since we will retry to
+ * launch the archiver from the postmaster main loop, we will get another
+ * chance later.
*/
-static pid_t
-pgarch_forkexec(void)
+bool
+PgArchCanRestart(void)
{
- char *av[10];
- int ac = 0;
-
- av[ac++] = "postgres";
+ static time_t last_pgarch_start_time = 0;
+ time_t curtime = time(NULL);
- av[ac++] = "--forkarch";
-
- av[ac++] = NULL; /* filled in by postmaster_forkexec */
+ /*
+ * allow to launch also for the first time and when something's wrong in
+ * the time values.
+ */
+ if (last_pgarch_start_time == 0 ||
+ curtime < last_pgarch_start_time ||
+ (curtime - last_pgarch_start_time) >= PGARCH_RESTART_INTERVAL)
+ {
+ last_pgarch_start_time = curtime;
- av[ac] = NULL;
- Assert(ac < lengthof(av));
+ return true;
+ }
- return postmaster_forkexec(ac, av);
+ return false;
}
-#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[])
+/* Main entry point for archiver process */
+void
+PgArchiverMain(void)
{
/*
* Ignore all signals usually bound to some action in the postmaster,
@@ -231,33 +177,51 @@ PgArchiverMain(int argc, char *argv[])
/* SIGQUIT handler was already set up by InitPostmasterChild */
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);
+ /* We shouldn't be launched unnecessarily. */
+ Assert(XLogArchivingActive());
+
+ /* Arrange to clean up at archiver exit */
+ on_shmem_exit(pgarch_die, 0);
+
+ /*
+ * Advertise our pgproc index so that backends can use our latch to wake
+ * us up while we're sleeping.
+ */
+ PgArch->pgprocno = MyProc->pgprocno;
pgarch_MainLoop();
- exit(0);
+ proc_exit(0);
}
-/* SIGUSR1 signal handler for archiver process */
-static void
-pgarch_waken(SIGNAL_ARGS)
+/*
+ * Wake up the archiver
+ */
+void
+PgArchWakeup(void)
{
- int save_errno = errno;
+ int arch_pgprocno = PgArch->pgprocno;
- /* set flag that there is work to be done */
- wakened = true;
- SetLatch(MyLatch);
-
- errno = save_errno;
+ /*
+ * We don't acquire ProcArrayLock here. It's actually fine because
+ * procLatch isn't ever freed, so we just can potentially set the wrong
+ * process' (or no process') latch. Even in that case the archiver will
+ * be relaunched shortly and will start archiving.
+ */
+ if (arch_pgprocno != INVALID_PGPROCNO)
+ SetLatch(&ProcGlobal->allProcs[arch_pgprocno].procLatch);
}
+
/* SIGUSR2 signal handler for archiver process */
static void
pgarch_waken_stop(SIGNAL_ARGS)
@@ -282,14 +246,6 @@ pgarch_MainLoop(void)
pg_time_t last_copy_time = 0;
bool time_to_stop;
- /*
- * We run the copy loop immediately upon entry, in case there are
- * unarchived files left over from a previous database run (or maybe the
- * archiver died unexpectedly). After that we wait for a signal or
- * timeout before doing more.
- */
- wakened = true;
-
/*
* There shouldn't be anything for the archiver to do except to wait for a
* signal ... however, the archiver exists to protect our data, so she
@@ -328,12 +284,8 @@ pgarch_MainLoop(void)
}
/* Do what we're here for */
- if (wakened || time_to_stop)
- {
- wakened = false;
- pgarch_ArchiverCopyLoop();
- last_copy_time = time(NULL);
- }
+ pgarch_ArchiverCopyLoop();
+ last_copy_time = time(NULL);
/*
* Sleep until a signal is received, or until a poll is forced by
@@ -354,13 +306,9 @@ pgarch_MainLoop(void)
WL_LATCH_SET | WL_TIMEOUT | WL_POSTMASTER_DEATH,
timeout * 1000L,
WAIT_EVENT_ARCHIVER_MAIN);
- if (rc & WL_TIMEOUT)
- wakened = true;
if (rc & WL_POSTMASTER_DEATH)
time_to_stop = true;
}
- else
- wakened = true;
}
/*
@@ -744,3 +692,15 @@ pgarch_archiveDone(char *xlog)
StatusFilePath(rlogdone, xlog, ".done");
(void) durable_rename(rlogready, rlogdone, WARNING);
}
+
+
+/*
+ * pgarch_die
+ *
+ * Exit-time cleanup handler
+ */
+static void
+pgarch_die(int code, Datum arg)
+{
+ PgArch->pgprocno = INVALID_PGPROCNO;
+}
diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index edab95a19e..e8af05c04e 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -443,9 +443,10 @@ static void InitPostmasterDeathWatchHandle(void);
* even during recovery.
*/
#define PgArchStartupAllowed() \
- ((XLogArchivingActive() && pmState == PM_RUN) || \
- (XLogArchivingAlways() && \
- (pmState == PM_RECOVERY || pmState == PM_HOT_STANDBY)))
+ (((XLogArchivingActive() && pmState == PM_RUN) || \
+ (XLogArchivingAlways() && \
+ (pmState == PM_RECOVERY || pmState == PM_HOT_STANDBY))) && \
+ PgArchCanRestart())
#ifdef EXEC_BACKEND
@@ -548,6 +549,7 @@ 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)
@@ -1792,7 +1794,7 @@ 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)
@@ -3007,7 +3009,7 @@ 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();
@@ -3142,20 +3144,22 @@ 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
+ * Was it the archiver? If exit status is zero (normal) or one (FATAL
+ * exit), we assume everything is all right just like normal backends
+ * and just try to restart a new one so that we immediately retry
+ * archiving remaining files. (If fail, we'll try again in future
+ * cycles of the postmaster's 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.
*/
if (pid == PgArchPID)
{
PgArchPID = 0;
- if (!EXIT_STATUS_0(exitstatus))
- LogChildExit(LOG, _("archiver process"),
- pid, exitstatus);
+ if (!EXIT_STATUS_0(exitstatus) && !EXIT_STATUS_1(exitstatus))
+ HandleChildCrash(pid, exitstatus,
+ _("archiver process"));
if (PgArchStartupAllowed())
- PgArchPID = pgarch_start();
+ PgArchPID = StartArchiver();
continue;
}
@@ -3403,7 +3407,7 @@ 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.
@@ -3609,19 +3613,16 @@ HandleChildCrash(int pid, int exitstatus, const char *procname)
signal_child(AutoVacPID, (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
- * simplifies the state-machine logic in the case where a shutdown request
- * arrives during crash processing.)
- */
- if (PgArchPID != 0 && take_action)
+ /* 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",
- "SIGQUIT",
+ (SendStop ? "SIGSTOP" : "SIGQUIT"),
(int) PgArchPID)));
- signal_child(PgArchPID, SIGQUIT);
+ signal_child(PgArchPID, (SendStop ? SIGSTOP : SIGQUIT));
}
/*
@@ -3804,12 +3805,11 @@ PostmasterStateMachine(void)
* (including autovac workers), no bgworkers (including unconnected
* ones), and no walwriter, autovac launcher or bgwriter. If we are
* doing crash recovery or an immediate shutdown then we expect the
- * checkpointer to exit as well, otherwise not. The archiver, stats,
- * and syslogger processes are disregarded since they are not
- * connected to shared memory; we also disregard dead_end children
- * here. Walsenders are also disregarded, they will be terminated
- * later after writing the checkpoint record, like the archiver
- * process.
+ * checkpointer to exit as well, otherwise not. The stats and
+ * syslogger processes are disregarded since they are not connected to
+ * shared memory; we also disregard dead_end children here. Walsenders
+ * and archiver are also disregarded, they will be terminated later
+ * after writing the checkpoint record.
*/
if (CountChildren(BACKEND_TYPE_ALL - BACKEND_TYPE_WALSND) == 0 &&
StartupPID == 0 &&
@@ -3912,6 +3912,7 @@ PostmasterStateMachine(void)
Assert(CheckpointerPID == 0);
Assert(WalWriterPID == 0);
Assert(AutoVacPID == 0);
+ Assert(PgArchPID == 0);
/* syslogger is not considered here */
pmState = PM_NO_CHILDREN;
}
@@ -5037,12 +5038,6 @@ SubPostmasterMain(int argc, char *argv[])
StartBackgroundWorker();
}
- if (strcmp(argv[1], "--forkarch") == 0)
- {
- /* Do not want to attach to shared memory */
-
- PgArchiverMain(argc, argv); /* does not return */
- }
if (strcmp(argv[1], "--forkcol") == 0)
{
/* Do not want to attach to shared memory */
@@ -5140,7 +5135,7 @@ 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
@@ -5194,16 +5189,6 @@ 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)
{
@@ -5445,6 +5430,10 @@ 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/backend/storage/ipc/ipci.c b/src/backend/storage/ipc/ipci.c
index f9bbe97b50..3e4ec53a97 100644
--- a/src/backend/storage/ipc/ipci.c
+++ b/src/backend/storage/ipc/ipci.c
@@ -144,6 +144,7 @@ CreateSharedMemoryAndSemaphores(void)
size = add_size(size, ReplicationOriginShmemSize());
size = add_size(size, WalSndShmemSize());
size = add_size(size, WalRcvShmemSize());
+ size = add_size(size, PgArchShmemSize());
size = add_size(size, ApplyLauncherShmemSize());
size = add_size(size, SnapMgrShmemSize());
size = add_size(size, BTreeShmemSize());
@@ -258,6 +259,7 @@ CreateSharedMemoryAndSemaphores(void)
ReplicationOriginShmemInit();
WalSndShmemInit();
WalRcvShmemInit();
+ PgArchShmemInit();
ApplyLauncherShmemInit();
/*
diff --git a/src/include/miscadmin.h b/src/include/miscadmin.h
index 54693e047a..013850ac28 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 d102a21ab7..1e47a143e1 100644
--- a/src/include/postmaster/pgarch.h
+++ b/src/include/postmaster/pgarch.h
@@ -26,14 +26,10 @@
#define MAX_XFN_CHARS 40
#define VALID_XFN_CHARS "0123456789ABCDEF.history.backup.partial"
-/* ----------
- * Functions called from postmaster
- * ----------
- */
-extern int pgarch_start(void);
-
-#ifdef EXEC_BACKEND
-extern void PgArchiverMain(int argc, char *argv[]) pg_attribute_noreturn();
-#endif
+extern Size PgArchShmemSize(void);
+extern void PgArchShmemInit(void);
+extern bool PgArchCanRestart(void);
+extern void PgArchiverMain(void) pg_attribute_noreturn();
+extern void PgArchWakeup(void);
#endif /* _PGARCH_H */
diff --git a/src/include/storage/pmsignal.h b/src/include/storage/pmsignal.h
index dbbed18f61..8ed4d87ae6 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 */
diff --git a/src/include/storage/proc.h b/src/include/storage/proc.h
index a777cb64a1..2fd1ff09a7 100644
--- a/src/include/storage/proc.h
+++ b/src/include/storage/proc.h
@@ -370,11 +370,11 @@ extern PGPROC *PreparedXactProcs;
* We set aside some extra PGPROC structures for auxiliary processes,
* ie things that aren't full-fledged backends but need shmem access.
*
- * Background writer, checkpointer and WAL writer run during normal operation.
- * Startup process and WAL receiver also consume 2 slots, but WAL writer is
- * launched only after startup has exited, so we only need 4 slots.
+ * Background writer, checkpointer, WAL writer and archiver run during normal
+ * operation. Startup process and WAL receiver also consume 2 slots, but WAL
+ * writer is launched only after startup has exited, so we only need 5 slots.
*/
-#define NUM_AUXILIARY_PROCS 4
+#define NUM_AUXILIARY_PROCS 5
/* configurable options */
extern PGDLLIMPORT int DeadlockTimeout;
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 99a34be465..78e852569e 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1572,6 +1572,7 @@ PGresAttValue
PGresParamDesc
PGresult
PGresult_data
+PgArchData
PHANDLE
PLAINTREE
PLUID_AND_ATTRIBUTES
--
2.27.0
----Next_Part(Fri_Mar_12_17_24_43_2021_866)----
^ permalink raw reply [nested|flat] 4+ messages in thread
* Re: Extract epoch from Interval weird behavior
@ 2022-02-24 09:47 Aleksander Alekseev <[email protected]>
0 siblings, 1 reply; 4+ messages in thread
From: Aleksander Alekseev @ 2022-02-24 09:47 UTC (permalink / raw)
To: Joseph Koshakow <[email protected]>; +Cc: PostgreSQL Hackers <[email protected]>
Hi Joseph,
> > Is this truncation on purpose? It seems like
> > EXTRACT is not accounting for leap years in
> > it's calculation.
Extracting an epoch from an interval is quite a strange case since
intervals are not connected to any specific dates.
For instance:
select extract('epoch' from interval '1 month')
.. returns 2592000 = 30*24*60*60. But what if the month is February? Should
we account for the different number of days for intervals like 6 months or
24 months?
Also, leap years don't just happen every 4 years. Here is the actual logic:
bool is_leap_year(int Y) {
if(Y % 400 == 0) return true;
else if(Y % 100 == 0) return false;
else if(Y % 4 == 0) return true;
else return false;
}
And what about leap seconds?
All in all, I don't think that the benefit of the proposed change outweighs
the fact that it will break the previous behavior for the users who may
rely on it. I suggest keeping it simple, i.e. the way it is now. What I
think we could do instead is explicitly document this behavior in [1].
[1]: https://www.postgresql.org/docs/current/functions-datetime.html
--
Best regards,
Aleksander Alekseev
^ permalink raw reply [nested|flat] 4+ messages in thread
* Re: Extract epoch from Interval weird behavior
@ 2022-02-24 15:17 Joseph Koshakow <[email protected]>
parent: Aleksander Alekseev <[email protected]>
0 siblings, 1 reply; 4+ messages in thread
From: Joseph Koshakow @ 2022-02-24 15:17 UTC (permalink / raw)
To: Aleksander Alekseev <[email protected]>; +Cc: PostgreSQL Hackers <[email protected]>
On Thu, Feb 24, 2022 at 4:47 AM Aleksander Alekseev
<[email protected]> wrote:
> Extracting an epoch from an interval is quite a strange case since intervals are not connected to any specific dates.
I agree, I think it's a weird use case and that it's probably not
worth fixing. Though it was fun for me to try.
>
> All in all, I don't think that the benefit of the proposed change outweighs the fact that it will break the previous behavior for the users who may rely on it. I suggest keeping it simple, i.e. the way it is now. What I think we could do instead is explicitly document this behavior in [1].
>
> [1]: https://www.postgresql.org/docs/current/functions-datetime.html
I do want to briefly mention, if I'm understanding the history of
EXTRACT correctly, that the previous behavior
actually was to multiply by 365.25, not 365. However The commit that
changed the return type from numeric [1]
changed that behavior. Looking through the discussions [2], I don't
see any mention of it, which makes me think
it was a mistake. However there is a lot of discussion around numeric
performance and being able to optimize
numeric division because every divisor was a power of 10. Fixing this
issue would break that assumption and
cause some performance degradations which probably isn't worth it.
[1]: https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=a2da77cdb4661826482ebf2ddba1f953bc74a...
[2]: https://www.postgresql.org/message-id/flat/[email protected]
- Joe Koshakow
^ permalink raw reply [nested|flat] 4+ messages in thread
* Re: Extract epoch from Interval weird behavior
@ 2022-02-24 16:27 Tom Lane <[email protected]>
parent: Joseph Koshakow <[email protected]>
0 siblings, 0 replies; 4+ messages in thread
From: Tom Lane @ 2022-02-24 16:27 UTC (permalink / raw)
To: Joseph Koshakow <[email protected]>; +Cc: Peter Eisentraut <[email protected]>; Aleksander Alekseev <[email protected]>; PostgreSQL Hackers <[email protected]>
Joseph Koshakow <[email protected]> writes:
> I do want to briefly mention, if I'm understanding the history of
> EXTRACT correctly, that the previous behavior
> actually was to multiply by 365.25, not 365. However The commit that
> changed the return type from numeric [1]
> changed that behavior. Looking through the discussions [2], I don't
> see any mention of it, which makes me think
> it was a mistake.
Indeed ... Peter?
regards, tom lane
^ permalink raw reply [nested|flat] 4+ messages in thread
end of thread, other threads:[~2022-02-24 16:27 UTC | newest]
Thread overview: 4+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
2021-03-11 09:01 [PATCH v55 3/3] Make archiver process an auxiliary process Kyotaro Horiguchi <[email protected]>
2022-02-24 09:47 Re: Extract epoch from Interval weird behavior Aleksander Alekseev <[email protected]>
2022-02-24 15:17 ` Re: Extract epoch from Interval weird behavior Joseph Koshakow <[email protected]>
2022-02-24 16:27 ` Re: Extract epoch from Interval weird behavior Tom Lane <[email protected]>
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