Movatterモバイル変換

[0]ホーム
URL:

Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly

 Sign up
Appearance settings

Commit944a17b

Browse files
committed
Delay write of pg_stats file to once every five minutes, during
shutdown, or when requested by a backend:It changes so the file is only written once every 5 minutes (changeableof course, I just picked something) instead of once every half second.It's still written when the stats collector shuts down, just as before.And it is now also written on backend request. A backend requests arewrite by simply sending a special stats message. It operates on theassumption that the backends aren't actually going to read thestatistics file very often, compared to how frequent it's written today.Magnus Hagander
1 parenta1e5331 commit944a17b

File tree

2 files changed

+121
-14
lines changed

2 files changed

+121
-14
lines changed

‎src/backend/postmaster/pgstat.c

Lines changed: 109 additions & 12 deletions
Original file line numberDiff line numberDiff line change
@@ -13,7 +13,7 @@
1313
*
1414
*Copyright (c) 2001-2006, PostgreSQL Global Development Group
1515
*
16-
*$PostgreSQL: pgsql/src/backend/postmaster/pgstat.c,v 1.123 2006/04/20 10:51:32 momjian Exp $
16+
*$PostgreSQL: pgsql/src/backend/postmaster/pgstat.c,v 1.124 2006/04/27 00:06:58 momjian Exp $
1717
* ----------
1818
*/
1919
#include"postgres.h"
@@ -28,6 +28,7 @@
2828
#include<arpa/inet.h>
2929
#include<signal.h>
3030
#include<time.h>
31+
#include<sys/stat.h>
3132

3233
#include"pgstat.h"
3334

@@ -66,12 +67,15 @@
6667
* Timer definitions.
6768
* ----------
6869
*/
69-
#definePGSTAT_STAT_INTERVAL500/* How often to write the status file;
70-
* in milliseconds. */
7170

72-
#definePGSTAT_RESTART_INTERVAL 60/* How often to attempt to restart a
73-
* failed statistics collector; in
74-
* seconds. */
71+
/* How often to write the status file, in milliseconds. */
72+
#definePGSTAT_STAT_INTERVAL(5*60*1000)
73+
74+
/*
75+
*How often to attempt to restart a failed statistics collector; in ms.
76+
*Must be at least PGSTAT_STAT_INTERVAL.
77+
*/
78+
#definePGSTAT_RESTART_INTERVAL (5*60*1000)
7579

7680
/* ----------
7781
* Amount of space reserved in pgstat_recvbuffer().
@@ -172,11 +176,12 @@ static void pgstat_drop_database(Oid databaseid);
172176
staticvoidpgstat_write_statsfile(void);
173177
staticvoidpgstat_read_statsfile(HTAB**dbhash,Oidonlydb,
174178
PgStat_StatBeEntry**betab,
175-
int*numbackends);
179+
int*numbackends,boolrewrite);
176180
staticvoidbackend_read_statsfile(void);
177181

178182
staticvoidpgstat_setheader(PgStat_MsgHdr*hdr,StatMsgTypemtype);
179183
staticvoidpgstat_send(void*msg,intlen);
184+
staticvoidpgstat_send_rewrite(void);
180185

181186
staticvoidpgstat_recv_bestart(PgStat_MsgBestart*msg,intlen);
182187
staticvoidpgstat_recv_beterm(PgStat_MsgBeterm*msg,intlen);
@@ -1449,6 +1454,24 @@ pgstat_send(void *msg, int len)
14491454
#endif
14501455
}
14511456

1457+
/*
1458+
* pgstat_send_rewrite() -
1459+
*
1460+
*Send a command to the collector to rewrite the stats file.
1461+
* ----------
1462+
*/
1463+
staticvoid
1464+
pgstat_send_rewrite(void)
1465+
{
1466+
PgStat_MsgRewritemsg;
1467+
1468+
if (pgStatSock<0)
1469+
return;
1470+
1471+
pgstat_setheader(&msg.m_hdr,PGSTAT_MTYPE_REWRITE);
1472+
pgstat_send(&msg,sizeof(msg));
1473+
}
1474+
14521475

14531476
/* ----------
14541477
* PgstatBufferMain() -
@@ -1549,7 +1572,7 @@ PgstatCollectorMain(int argc, char *argv[])
15491572
fd_setrfds;
15501573
intreadPipe;
15511574
intlen=0;
1552-
structitimervaltimeout;
1575+
structitimervaltimeout,canceltimeout;
15531576
boolneed_timer= false;
15541577

15551578
MyProcPid=getpid();/* reset MyProcPid */
@@ -1604,12 +1627,15 @@ PgstatCollectorMain(int argc, char *argv[])
16041627
timeout.it_value.tv_sec=PGSTAT_STAT_INTERVAL /1000;
16051628
timeout.it_value.tv_usec=PGSTAT_STAT_INTERVAL %1000;
16061629

1630+
/* Values set to zero will cancel the active timer */
1631+
MemSet(&canceltimeout,0,sizeof(structitimerval));
1632+
16071633
/*
16081634
* Read in an existing statistics stats file or initialize the stats to
16091635
* zero.
16101636
*/
16111637
pgStatRunningInCollector= true;
1612-
pgstat_read_statsfile(&pgStatDBHash,InvalidOid,NULL,NULL);
1638+
pgstat_read_statsfile(&pgStatDBHash,InvalidOid,NULL,NULL, false);
16131639

16141640
/*
16151641
* Create the known backends table
@@ -1764,6 +1790,12 @@ PgstatCollectorMain(int argc, char *argv[])
17641790
pgstat_recv_analyze((PgStat_MsgAnalyze*)&msg,nread);
17651791
break;
17661792

1793+
casePGSTAT_MTYPE_REWRITE:
1794+
need_statwrite= true;
1795+
/* Disable the timer - it will be restarted on next data update */
1796+
setitimer(ITIMER_REAL,&canceltimeout,NULL);
1797+
break;
1798+
17671799
default:
17681800
break;
17691801
}
@@ -2344,7 +2376,7 @@ comparePids(const void *v1, const void *v2)
23442376
*/
23452377
staticvoid
23462378
pgstat_read_statsfile(HTAB**dbhash,Oidonlydb,
2347-
PgStat_StatBeEntry**betab,int*numbackends)
2379+
PgStat_StatBeEntry**betab,int*numbackends,boolrewrite)
23482380
{
23492381
PgStat_StatDBEntry*dbentry;
23502382
PgStat_StatDBEntrydbbuf;
@@ -2363,6 +2395,71 @@ pgstat_read_statsfile(HTAB **dbhash, Oid onlydb,
23632395
MemoryContextuse_mcxt;
23642396
intmcxt_flags;
23652397

2398+
2399+
if (rewrite)
2400+
{
2401+
/*
2402+
* To force a rewrite of the stats file from the collector, send
2403+
* a REWRITE message to the stats collector. Then wait for the file
2404+
* to change. On Unix, we wait for the inode to change (as the file
2405+
* is renamed into place from a different file). Win32 has no concept
2406+
* of inodes, so we wait for the date on the file to change instead.
2407+
* We can do this on win32 because we have high-res timing on the
2408+
* file dates, but we can't on unix, because it has 1sec resolution
2409+
* on the fields in struct stat.
2410+
*/
2411+
inti;
2412+
#ifndefWIN32
2413+
structstatst1,st2;
2414+
2415+
if (stat(PGSTAT_STAT_FILENAME,&st1))
2416+
{
2417+
/* Assume no file there yet */
2418+
st1.st_ino=0;
2419+
}
2420+
st2.st_ino=0;
2421+
#else
2422+
WIN32_FILE_ATTRIBUTE_DATAfd1,fd2;
2423+
2424+
if (!GetFileAttributesEx(PGSTAT_STAT_FILENAME,GetFileExInfoStandard,&fd1))
2425+
{
2426+
fd1.ftLastWriteTime.dwLowDateTime=0;
2427+
fd1.ftLastWriteTime.dwHighDateTime=0;
2428+
}
2429+
fd2.ftLastWriteTime.dwLowDateTime=0;
2430+
fd2.ftLastWriteTime.dwHighDateTime=0;
2431+
#endif
2432+
2433+
2434+
/* Send rewrite message */
2435+
pgstat_send_rewrite();
2436+
2437+
/* Now wait for the file to change */
2438+
for (i=0;i<50;i++)
2439+
{
2440+
#ifndefWIN32
2441+
if (!stat(PGSTAT_STAT_FILENAME,&st2))
2442+
{
2443+
if (st2.st_ino!=st1.st_ino)
2444+
break;
2445+
}
2446+
#else
2447+
if (GetFileAttributesEx(PGSTAT_STAT_FILENAME,GetFileExInfoStandard,&fd2))
2448+
{
2449+
if (fd1.ftLastWriteTime.dwLowDateTime!=fd2.ftLastWriteTime.dwLowDateTime||
2450+
fd1.ftLastWriteTime.dwHighDateTime!=fd2.ftLastWriteTime.dwHighDateTime)
2451+
break;
2452+
}
2453+
#endif
2454+
2455+
pg_usleep(50000);
2456+
}
2457+
if (i >=50)
2458+
ereport(WARNING,
2459+
(errmsg("pgstat update timeout")));
2460+
/* Fallthrough and read the old file anyway - old data better than no data */
2461+
}
2462+
23662463
/*
23672464
* If running in the collector or the autovacuum process, we use the
23682465
* DynaHashCxt memory context.If running in a backend, we use the
@@ -2681,7 +2778,7 @@ backend_read_statsfile(void)
26812778
return;
26822779
Assert(!pgStatRunningInCollector);
26832780
pgstat_read_statsfile(&pgStatDBHash,InvalidOid,
2684-
&pgStatBeTable,&pgStatNumBackends);
2781+
&pgStatBeTable,&pgStatNumBackends, true);
26852782
}
26862783
else
26872784
{
@@ -2691,7 +2788,7 @@ backend_read_statsfile(void)
26912788
{
26922789
Assert(!pgStatRunningInCollector);
26932790
pgstat_read_statsfile(&pgStatDBHash,MyDatabaseId,
2694-
&pgStatBeTable,&pgStatNumBackends);
2791+
&pgStatBeTable,&pgStatNumBackends, true);
26952792
pgStatDBHashXact=topXid;
26962793
}
26972794
}

‎src/include/pgstat.h

Lines changed: 12 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -5,7 +5,7 @@
55
*
66
*Copyright (c) 2001-2006, PostgreSQL Global Development Group
77
*
8-
*$PostgreSQL: pgsql/src/include/pgstat.h,v 1.43 2006/04/06 20:38:00 tgl Exp $
8+
*$PostgreSQL: pgsql/src/include/pgstat.h,v 1.44 2006/04/27 00:06:59 momjian Exp $
99
* ----------
1010
*/
1111
#ifndefPGSTAT_H
@@ -32,7 +32,8 @@ typedef enum StatMsgType
3232
PGSTAT_MTYPE_RESETCOUNTER,
3333
PGSTAT_MTYPE_AUTOVAC_START,
3434
PGSTAT_MTYPE_VACUUM,
35-
PGSTAT_MTYPE_ANALYZE
35+
PGSTAT_MTYPE_ANALYZE,
36+
PGSTAT_MTYPE_REWRITE
3637
}StatMsgType;
3738

3839
/* ----------
@@ -107,6 +108,15 @@ typedef struct PgStat_MsgDummy
107108
charm_dummy[512];
108109
}PgStat_MsgDummy;
109110

111+
/* ----------
112+
* PgStat_MsgRewrite Sent by backends to cause a rewrite of the stats file
113+
* ----------
114+
*/
115+
typedefstructPgstat_MsgRewrite
116+
{
117+
PgStat_MsgHdrm_hdr;
118+
}PgStat_MsgRewrite;
119+
110120
/* ----------
111121
* PgStat_MsgBestartSent by the backend on startup
112122
* ----------

0 commit comments

Comments
 (0)
[8]ページ先頭
©2009-2025 Movatter.jp