Add some logging code for unexpected cases in pgstat.c, particularly being

unable to read a stats file for reasons other than ENOENT, and having to reset
last_statrequest because it's later than current time in the collector.
Not clear if this will shed any light on the "pgstat wait timeout" business,
but it seems like a good idea in general.

In passing, do some message-style-police work on recently-added
pgstat_reset_shared_counters code.
This commit is contained in:
Tom Lane 2010-03-12 22:19:19 +00:00
parent d75f7a01bf
commit 52e2b33a55
1 changed files with 50 additions and 18 deletions

View File

@ -13,7 +13,7 @@
*
* Copyright (c) 2001-2010, PostgreSQL Global Development Group
*
* $PostgreSQL: pgsql/src/backend/postmaster/pgstat.c,v 1.201 2010/02/26 02:00:55 momjian Exp $
* $PostgreSQL: pgsql/src/backend/postmaster/pgstat.c,v 1.202 2010/03/12 22:19:19 tgl Exp $
* ----------
*/
#include "postgres.h"
@ -1177,12 +1177,10 @@ pgstat_reset_shared_counters(const char *target)
if (strcmp(target, "bgwriter") == 0)
msg.m_resettarget = RESET_BGWRITER;
else
{
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("unrecognized reset target: '%s'", target),
errhint("allowed targets are 'bgwriter'.")));
}
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("unrecognized reset target: \"%s\"", target),
errhint("Target must be \"bgwriter\".")));
pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_RESETSHAREDCOUNTER);
pgstat_send(&msg, sizeof(msg));
@ -3292,11 +3290,15 @@ pgstat_write_statsfile(bool permanent)
/*
* It's not entirely clear whether there could be clock skew between
* backends and the collector; but just in case someone manages to
* send us a stats request time that's far in the future, reset it.
* send us a stats request time that's in the future, reset it.
* This ensures that no inquiry message can cause more than one stats
* file write to occur.
*/
last_statrequest = last_statwrite;
if (last_statrequest > last_statwrite)
{
elog(LOG, "last_statrequest is in the future, resetting");
last_statrequest = last_statwrite;
}
}
if (permanent)
@ -3355,9 +3357,20 @@ pgstat_read_statsfile(Oid onlydb, bool permanent)
* Try to open the status file. If it doesn't exist, the backends simply
* return zero for anything and the collector simply starts from scratch
* with empty counters.
*
* ENOENT is a possibility if the stats collector is not running or has
* not yet written the stats file the first time. Any other failure
* condition is suspicious.
*/
if ((fpin = AllocateFile(statfile, PG_BINARY_R)) == NULL)
{
if (errno != ENOENT)
ereport(pgStatRunningInCollector ? LOG : WARNING,
(errcode_for_file_access(),
errmsg("could not open statistics file \"%s\": %m",
statfile)));
return dbhash;
}
/*
* Verify it's of the expected format.
@ -3366,7 +3379,7 @@ pgstat_read_statsfile(Oid onlydb, bool permanent)
|| format_id != PGSTAT_FILE_FORMAT_ID)
{
ereport(pgStatRunningInCollector ? LOG : WARNING,
(errmsg("corrupted pgstat.stat file")));
(errmsg("corrupted statistics file \"%s\"", statfile)));
goto done;
}
@ -3376,7 +3389,7 @@ pgstat_read_statsfile(Oid onlydb, bool permanent)
if (fread(&globalStats, 1, sizeof(globalStats), fpin) != sizeof(globalStats))
{
ereport(pgStatRunningInCollector ? LOG : WARNING,
(errmsg("corrupted pgstat.stat file")));
(errmsg("corrupted statistics file \"%s\"", statfile)));
goto done;
}
@ -3398,7 +3411,8 @@ pgstat_read_statsfile(Oid onlydb, bool permanent)
fpin) != offsetof(PgStat_StatDBEntry, tables))
{
ereport(pgStatRunningInCollector ? LOG : WARNING,
(errmsg("corrupted pgstat.stat file")));
(errmsg("corrupted statistics file \"%s\"",
statfile)));
goto done;
}
@ -3412,7 +3426,8 @@ pgstat_read_statsfile(Oid onlydb, bool permanent)
if (found)
{
ereport(pgStatRunningInCollector ? LOG : WARNING,
(errmsg("corrupted pgstat.stat file")));
(errmsg("corrupted statistics file \"%s\"",
statfile)));
goto done;
}
@ -3474,7 +3489,8 @@ pgstat_read_statsfile(Oid onlydb, bool permanent)
fpin) != sizeof(PgStat_StatTabEntry))
{
ereport(pgStatRunningInCollector ? LOG : WARNING,
(errmsg("corrupted pgstat.stat file")));
(errmsg("corrupted statistics file \"%s\"",
statfile)));
goto done;
}
@ -3491,7 +3507,8 @@ pgstat_read_statsfile(Oid onlydb, bool permanent)
if (found)
{
ereport(pgStatRunningInCollector ? LOG : WARNING,
(errmsg("corrupted pgstat.stat file")));
(errmsg("corrupted statistics file \"%s\"",
statfile)));
goto done;
}
@ -3506,7 +3523,8 @@ pgstat_read_statsfile(Oid onlydb, bool permanent)
fpin) != sizeof(PgStat_StatFuncEntry))
{
ereport(pgStatRunningInCollector ? LOG : WARNING,
(errmsg("corrupted pgstat.stat file")));
(errmsg("corrupted statistics file \"%s\"",
statfile)));
goto done;
}
@ -3523,7 +3541,8 @@ pgstat_read_statsfile(Oid onlydb, bool permanent)
if (found)
{
ereport(pgStatRunningInCollector ? LOG : WARNING,
(errmsg("corrupted pgstat.stat file")));
(errmsg("corrupted statistics file \"%s\"",
statfile)));
goto done;
}
@ -3538,7 +3557,8 @@ pgstat_read_statsfile(Oid onlydb, bool permanent)
default:
ereport(pgStatRunningInCollector ? LOG : WARNING,
(errmsg("corrupted pgstat.stat file")));
(errmsg("corrupted statistics file \"%s\"",
statfile)));
goto done;
}
}
@ -3568,10 +3588,18 @@ pgstat_read_statsfile_timestamp(bool permanent, TimestampTz *ts)
const char *statfile = permanent ? PGSTAT_STAT_PERMANENT_FILENAME : pgstat_stat_filename;
/*
* Try to open the status file.
* Try to open the status file. As above, anything but ENOENT is worthy
* of complaining about.
*/
if ((fpin = AllocateFile(statfile, PG_BINARY_R)) == NULL)
{
if (errno != ENOENT)
ereport(pgStatRunningInCollector ? LOG : WARNING,
(errcode_for_file_access(),
errmsg("could not open statistics file \"%s\": %m",
statfile)));
return false;
}
/*
* Verify it's of the expected format.
@ -3579,6 +3607,8 @@ pgstat_read_statsfile_timestamp(bool permanent, TimestampTz *ts)
if (fread(&format_id, 1, sizeof(format_id), fpin) != sizeof(format_id)
|| format_id != PGSTAT_FILE_FORMAT_ID)
{
ereport(pgStatRunningInCollector ? LOG : WARNING,
(errmsg("corrupted statistics file \"%s\"", statfile)));
FreeFile(fpin);
return false;
}
@ -3588,6 +3618,8 @@ pgstat_read_statsfile_timestamp(bool permanent, TimestampTz *ts)
*/
if (fread(&myGlobalStats, 1, sizeof(myGlobalStats), fpin) != sizeof(myGlobalStats))
{
ereport(pgStatRunningInCollector ? LOG : WARNING,
(errmsg("corrupted statistics file \"%s\"", statfile)));
FreeFile(fpin);
return false;
}