*
* - Add a pgstat config column to pg_database, so this
* entire thing can be enabled/disabled on a per db base.
- * Not to be done before 7.2 - requires catalog change and
- * thus an initdb and we might want to provide this as a
- * patch for 7.1.
*
- * Copyright (c) 2001, PostgreSQL Global Development Group
+ * Copyright (c) 2001-2003, PostgreSQL Global Development Group
*
- * $Header: /cvsroot/pgsql/src/backend/postmaster/pgstat.c,v 1.33 2003/04/25 01:24:00 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/postmaster/pgstat.c,v 1.34 2003/04/26 02:57:14 tgl Exp $
* ----------
*/
#include "postgres.h"
#include <errno.h>
#include <signal.h>
+#include "pgstat.h"
+
#include "access/xact.h"
#include "access/heapam.h"
#include "catalog/catname.h"
#include "utils/ps_status.h"
#include "utils/syscache.h"
-#include "pgstat.h"
-
/* ----------
* GUC parameters
bool pgstat_collect_blocklevel = false;
/* ----------
+ * Other global variables
+ * ----------
+ */
+bool pgstat_is_running = false;
+
+/* ----------
* Local data
* ----------
*/
static struct sockaddr_in pgStatAddr;
static int pgStatPmPipe[2] = {-1, -1};
-static int pgStatRunning = 0;
static int pgStatPid;
+static time_t last_pgstat_start_time;
static long pgStatNumMessages = 0;
* pgstat_init() -
*
* Called from postmaster at startup. Create the resources required
- * by the statistics collector process.
- *
- * NOTE: failure exit from this routine causes the postmaster to abort.
- * This is unfriendly and should not be done except in dire straits.
- * Better to let the postmaster start with stats collection disabled.
+ * by the statistics collector process. If unable to do so, do not
+ * fail --- better to let the postmaster start with stats collection
+ * disabled.
* ----------
*/
-int
+void
pgstat_init(void)
{
int alen;
* Nothing else required if collector will not get started
*/
if (!pgstat_collect_startcollector)
- return 0;
+ return;
/*
* Create the UDP socket for sending and receiving statistic messages
goto startup_failed;
}
- return 0;
+ return;
startup_failed:
if (pgStatSock >= 0)
pgStatSock = -1;
/* Adjust GUC variables to suppress useless activity */
+ pgstat_collect_startcollector = false;
pgstat_collect_querystring = false;
pgstat_collect_tuplelevel = false;
pgstat_collect_blocklevel = false;
-
- return 0;
}
* pgstat_start() -
*
* Called from postmaster at startup or after an existing collector
- * died. Fire up a fresh statistics collector.
+ * died. Attempt to fire up a fresh statistics collector.
*
- * NOTE: failure exit from this routine causes the postmaster to abort.
+ * Note: if fail, we will be called again from the postmaster main loop.
* ----------
*/
-int
+void
pgstat_start(void)
{
+ time_t curtime;
+
/*
* Do nothing if no collector needed
*/
- if (!pgstat_collect_startcollector)
- return 0;
+ if (pgstat_is_running || !pgstat_collect_startcollector)
+ return;
+
+ /*
+ * Do nothing if too soon since last collector start. This is a
+ * safety valve to protect against continuous respawn attempts if
+ * the collector 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_pgstat_start_time) <
+ (unsigned int) PGSTAT_RESTART_INTERVAL)
+ return;
+ last_pgstat_start_time = curtime;
/*
- * Check that the socket is there, else pgstat_init failed
+ * Check that the socket is there, else pgstat_init failed.
*/
if (pgStatSock < 0)
{
elog(LOG, "PGSTAT: statistics collector startup skipped");
- return 0;
+ /*
+ * We can only get here if someone tries to manually turn
+ * pgstat_collect_startcollector on after it had been off.
+ */
+ pgstat_collect_startcollector = false;
+ return;
}
/*
- * Then fork off the collector. Remember its PID for pgstat_ispgstat.
+ * Okay, fork off the collector. Remember its PID for pgstat_ispgstat.
*/
fflush(stdout);
beos_backend_startup_failed();
#endif
elog(LOG, "PGSTAT: fork() failed: %m");
- pgStatRunning = 0;
- return 0;
+ return;
case 0:
break;
default:
- pgStatRunning = 1;
- return 0;
+ pgstat_is_running = true;
+ return;
}
/* in postmaster child ... */
* was the statistics collector.
* ----------
*/
-int
+bool
pgstat_ispgstat(int pid)
{
- if (pgStatRunning == 0)
- return 0;
+ if (!pgstat_is_running)
+ return false;
if (pgStatPid != pid)
- return 0;
+ return false;
+
+ /* Oh dear ... */
+ pgstat_is_running = false;
- return 1;
+ return true;
}
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/postmaster/postmaster.c,v 1.314 2003/04/22 00:08:06 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/postmaster/postmaster.c,v 1.315 2003/04/26 02:57:14 tgl Exp $
*
* NOTES
*
}
/*
- * Initialize and startup the statistics collector process
+ * Initialize and try to startup the statistics collector process
*/
- if (pgstat_init() < 0)
- ExitPostmaster(1);
- if (pgstat_start() < 0)
- ExitPostmaster(1);
+ pgstat_init();
+ pgstat_start();
/*
* Load cached files for client authentication.
ConnFree(port);
}
}
+
+ /* If we have lost the stats collector, try to start a new one */
+ if (!pgstat_is_running)
+ pgstat_start();
}
}
#endif
/*
- * Check if this child was the statistics collector. If so, start
- * a new one.
+ * Check if this child was the statistics collector. If so,
+ * try to start a new one. (If fail, we'll try again in
+ * future cycles of the main loop.)
*/
if (pgstat_ispgstat(pid))
{
*
* Definitions for the PostgreSQL statistics collector daemon.
*
- * Copyright (c) 2001, PostgreSQL Global Development Group
+ * Copyright (c) 2001-2003, PostgreSQL Global Development Group
*
- * $Id: pgstat.h,v 1.13 2003/03/20 03:34:56 momjian Exp $
+ * $Id: pgstat.h,v 1.14 2003/04/26 02:57:14 tgl Exp $
* ----------
*/
#ifndef PGSTAT_H
#define PGSTAT_H
+#include "utils/hsearch.h"
#include "utils/nabstime.h"
+#include "utils/rel.h"
+
/* ----------
* Paths for the statistics files. The %s is replaced with the
* ----------
*/
#define PGSTAT_STAT_INTERVAL 500 /* How often to write the status */
- /* file, in milliseconds. */
+ /* file; in milliseconds. */
#define PGSTAT_DESTROY_DELAY 10000 /* How long to keep destroyed */
- /* objects known to give delayed */
- /* UDP packets time to arrive, */
+ /* objects known, to give delayed */
+ /* UDP packets time to arrive; */
/* in milliseconds. */
-#define PGSTAT_DESTROY_COUNT (PGSTAT_DESTROY_DELAY \
- / PGSTAT_STAT_INTERVAL)
+#define PGSTAT_DESTROY_COUNT (PGSTAT_DESTROY_DELAY / PGSTAT_STAT_INTERVAL)
+#define PGSTAT_RESTART_INTERVAL 60 /* How often to attempt to restart */
+ /* a failed statistics collector; in seconds. */
/* ----------
* How much of the actual query string to send to the collector.
/* ----------
- * Global variables
+ * GUC parameters
* ----------
*/
extern bool pgstat_collect_startcollector;
extern bool pgstat_collect_blocklevel;
/* ----------
+ * Other global variables
+ * ----------
+ */
+extern bool pgstat_is_running;
+
+/* ----------
* Functions called from postmaster
* ----------
*/
-extern int pgstat_init(void);
-extern int pgstat_start(void);
-extern int pgstat_ispgstat(int pid);
+extern void pgstat_init(void);
+extern void pgstat_start(void);
+extern bool pgstat_ispgstat(int pid);
extern void pgstat_close_sockets(void);
extern void pgstat_beterm(int pid);
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