Index: src/backend/postmaster/pgstat.c =================================================================== RCS file: /projects/cvsroot/pgsql/src/backend/postmaster/pgstat.c,v retrieving revision 1.181 diff -c -r1.181 pgstat.c *** src/backend/postmaster/pgstat.c 25 Aug 2008 18:55:43 -0000 1.181 --- src/backend/postmaster/pgstat.c 8 Sep 2008 21:00:17 -0000 *************** *** 85,90 **** --- 85,97 ---- #define PGSTAT_SELECT_TIMEOUT 2 /* How often to check for postmaster * death; in seconds. */ + #define PGSTAT_POLL_RETRY_DELAY 5 /* How long to pause between statistics + * update requests; in milliseconds. */ + + #define PGSTAT_POLL_TIME 5000 /* How long are we allowed to poll for + * the stats file; in milliseconds. */ + + #define PGSTAT_POLL_LOOP_COUNT (PGSTAT_POLL_TIME / PGSTAT_POLL_RETRY_DELAY) /* ---------- * The initial size hints for the hash tables used in the collector. *************** *** 159,164 **** --- 166,177 ---- static HTAB *pgStatFunctions = NULL; /* + * Indicates if backend has some function stats which it hasn't yet + * sent to the collector. + */ + static bool have_function_stats = false; + + /* * Tuple insertion/deletion counts for an open transaction can't be propagated * into PgStat_TableStatus counters until we know if it is going to commit * or abort. Hence, we keep these counts in per-subxact structs that live *************** *** 201,208 **** */ static PgStat_GlobalStats globalStats; static volatile bool need_exit = false; - static volatile bool need_statwrite = false; static volatile bool got_SIGHUP = false; /* --- 214,225 ---- */ static PgStat_GlobalStats globalStats; + /* Last time the collector wrote the stats file */ + static TimestampTz last_statwrite; + /* Latest statistics request from backend */ + static TimestampTz last_statrequest; + static volatile bool need_exit = false; static volatile bool got_SIGHUP = false; /* *************** *** 223,229 **** NON_EXEC_STATIC void PgstatCollectorMain(int argc, char *argv[]); static void pgstat_exit(SIGNAL_ARGS); - static void force_statwrite(SIGNAL_ARGS); static void pgstat_beshutdown_hook(int code, Datum arg); static void pgstat_sighup_handler(SIGNAL_ARGS); --- 240,245 ---- *************** *** 254,259 **** --- 270,276 ---- static void pgstat_recv_bgwriter(PgStat_MsgBgWriter *msg, int len); static void pgstat_recv_funcstat(PgStat_MsgFuncstat *msg, int len); static void pgstat_recv_funcpurge(PgStat_MsgFuncpurge *msg, int len); + static void pgstat_recv_inquiry(PgStat_MsgInquiry *msg, int len); /* ------------------------------------------------------------ *************** *** 655,663 **** int i; /* Don't expend a clock check if nothing to do */ ! /* Note: we ignore pending function stats in this test ... OK? */ ! if (pgStatTabList == NULL || ! pgStatTabList->tsa_used == 0) return; /* --- 672,679 ---- int i; /* Don't expend a clock check if nothing to do */ ! if ((pgStatTabList == NULL || pgStatTabList->tsa_used == 0) ! && !have_function_stats) return; /* *************** *** 823,828 **** --- 839,846 ---- if (msg.m_nentries > 0) pgstat_send(&msg, offsetof(PgStat_MsgFuncstat, m_entry[0]) + msg.m_nentries * sizeof(PgStat_FunctionEntry)); + + have_function_stats = false; } *************** *** 1341,1346 **** --- 1359,1367 ---- fs->f_numcalls++; fs->f_time = f_total; INSTR_TIME_ADD(fs->f_time_self, f_self); + + /* indicate that we have something to upload */ + have_function_stats = true; } *************** *** 2463,2468 **** --- 2484,2505 ---- hdr->m_type = mtype; } + /* ---------- + * pgstat_send_inquiry() - + * + * Notify collector that we need fresh data. + * ts is used to specify the minimum valid timestamp for the file. + * ---------- + */ + static void + pgstat_send_inquiry(TimestampTz ts) + { + PgStat_MsgInquiry msg; + + pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_INQUIRY); + msg.inquiry_time = ts; + pgstat_send(&msg, sizeof(msg)); + } /* ---------- * pgstat_send() - *************** *** 2538,2545 **** NON_EXEC_STATIC void PgstatCollectorMain(int argc, char *argv[]) { - struct itimerval write_timeout; - bool need_timer = false; int len; PgStat_Msg msg; --- 2575,2580 ---- *************** *** 2571,2583 **** /* * Ignore all signals usually bound to some action in the postmaster, ! * except SIGQUIT and SIGALRM. */ pqsignal(SIGHUP, pgstat_sighup_handler); pqsignal(SIGINT, SIG_IGN); pqsignal(SIGTERM, SIG_IGN); pqsignal(SIGQUIT, pgstat_exit); - pqsignal(SIGALRM, force_statwrite); pqsignal(SIGPIPE, SIG_IGN); pqsignal(SIGUSR1, SIG_IGN); pqsignal(SIGUSR2, SIG_IGN); --- 2606,2617 ---- /* * Ignore all signals usually bound to some action in the postmaster, ! * except SIGQUIT */ pqsignal(SIGHUP, pgstat_sighup_handler); pqsignal(SIGINT, SIG_IGN); pqsignal(SIGTERM, SIG_IGN); pqsignal(SIGQUIT, pgstat_exit); pqsignal(SIGPIPE, SIG_IGN); pqsignal(SIGUSR1, SIG_IGN); pqsignal(SIGUSR2, SIG_IGN); *************** *** 2594,2609 **** init_ps_display("stats collector process", "", "", ""); /* - * Arrange to write the initial status file right away - */ - need_statwrite = true; - - /* Preset the delay between status file writes */ - MemSet(&write_timeout, 0, sizeof(struct itimerval)); - write_timeout.it_value.tv_sec = PGSTAT_STAT_INTERVAL / 1000; - write_timeout.it_value.tv_usec = (PGSTAT_STAT_INTERVAL % 1000) * 1000; - - /* * Read in an existing statistics stats file or initialize the stats to * zero. */ --- 2628,2633 ---- *************** *** 2645,2668 **** { ProcessConfigFile(PGC_SIGHUP); got_SIGHUP = false; ! need_statwrite = true; } /* ! * If time to write the stats file, do so. Note that the alarm ! * interrupt isn't re-enabled immediately, but only after we next ! * receive a stats message; so no cycles are wasted when there is ! * nothing going on. */ ! if (need_statwrite) { /* Check for postmaster death; if so we'll write file below */ if (!PostmasterIsAlive(true)) break; - pgstat_write_statsfile(false); - need_statwrite = false; - need_timer = true; } /* --- 2669,2687 ---- { ProcessConfigFile(PGC_SIGHUP); got_SIGHUP = false; ! last_statrequest = last_statwrite; } /* ! * Write the stats file if so requested and not satisfied by ! * existing file. */ ! if (TimestampDifferenceExceeds(last_statwrite, last_statrequest, 0)) { /* Check for postmaster death; if so we'll write file below */ if (!PostmasterIsAlive(true)) break; pgstat_write_statsfile(false); } /* *************** *** 2797,2817 **** pgstat_recv_funcpurge((PgStat_MsgFuncpurge *) &msg, len); break; ! default: break; - } ! /* ! * If this is the first message after we wrote the stats file the ! * last time, enable the alarm interrupt to make it be written ! * again later. ! */ ! if (need_timer) ! { ! if (setitimer(ITIMER_REAL, &write_timeout, NULL)) ! ereport(ERROR, ! (errmsg("could not set statistics collector timer: %m"))); ! need_timer = false; } } else --- 2816,2827 ---- pgstat_recv_funcpurge((PgStat_MsgFuncpurge *) &msg, len); break; ! case PGSTAT_MTYPE_INQUIRY: ! pgstat_recv_inquiry((PgStat_MsgInquiry *)&msg, len); break; ! default: ! break; } } else *************** *** 2841,2853 **** need_exit = true; } - /* SIGALRM signal handler for collector process */ - static void - force_statwrite(SIGNAL_ARGS) - { - need_statwrite = true; - } - /* SIGHUP handler for collector process */ static void pgstat_sighup_handler(SIGNAL_ARGS) --- 2851,2856 ---- *************** *** 2943,2949 **** /* * Open the statistics temp file to write out the current values. */ ! fpout = fopen(tmpfile, PG_BINARY_W); if (fpout == NULL) { ereport(LOG, --- 2946,2952 ---- /* * Open the statistics temp file to write out the current values. */ ! fpout = AllocateFile(tmpfile, PG_BINARY_W); if (fpout == NULL) { ereport(LOG, *************** *** 2954,2963 **** } /* ! * Write the file header --- currently just a format ID. */ format_id = PGSTAT_FILE_FORMAT_ID; fwrite(&format_id, sizeof(format_id), 1, fpout); /* * Write global stats struct --- 2957,2968 ---- } /* ! * Write the file header --- currently just a format ID and a timestamp. */ format_id = PGSTAT_FILE_FORMAT_ID; fwrite(&format_id, sizeof(format_id), 1, fpout); + last_statwrite = GetCurrentTimestamp(); + fwrite(&last_statwrite, sizeof(last_statwrite), 1, fpout); /* * Write global stats struct *************** *** 3017,3026 **** (errcode_for_file_access(), errmsg("could not write temporary statistics file \"%s\": %m", tmpfile))); ! fclose(fpout); unlink(tmpfile); } ! else if (fclose(fpout) < 0) { ereport(LOG, (errcode_for_file_access(), --- 3022,3031 ---- (errcode_for_file_access(), errmsg("could not write temporary statistics file \"%s\": %m", tmpfile))); ! FreeFile(fpout); unlink(tmpfile); } ! else if (FreeFile(fpout) < 0) { ereport(LOG, (errcode_for_file_access(), *************** *** 3108,3113 **** --- 3113,3126 ---- goto done; } + /* Skip over the timestamp */ + if (fseek(fpin, sizeof(TimestampTz), SEEK_CUR) != 0) + { + ereport(pgStatRunningInCollector ? LOG : WARNING, + (errmsg("corrupted pgstat.stat file"))); + goto done; + } + /* * Read global stats struct */ *************** *** 3297,3307 **** --- 3310,3363 ---- static void backend_read_statsfile(void) { + TimestampTz file_min_ts; + bool stats_ready = false; + int count; + /* already read it? */ if (pgStatDBHash) return; Assert(!pgStatRunningInCollector); + /* + * This is the earliest timestamp we can use. Usually we can tolerate + * up to PGSTAT_STAT_INTERVAL ms stale files. + */ + file_min_ts = TimestampTzPlusMilliseconds(GetCurrentTimestamp(), + -PGSTAT_STAT_INTERVAL); + + /* + * Loop until fresh enough stats file is available or we ran out of time. + * The stats inquiry message is resent in case collector drops our first + * message. + */ + for (count = 0; !stats_ready && count < PGSTAT_POLL_LOOP_COUNT; count++) + { + TimestampTz ts; + FILE *fp; + + CHECK_FOR_INTERRUPTS(); + + /* Read the timestamp from beginning of the stats file */ + if ((fp = AllocateFile(pgstat_stat_filename, PG_BINARY_R)) != NULL) + { + fseek(fp, sizeof(int32), SEEK_SET); + fread(&ts, sizeof(ts), 1, fp); + if (!ferror(fp) && TimestampDifferenceExceeds(file_min_ts, ts, 0)) + stats_ready = true; + FreeFile(fp); + } + + if (!stats_ready) + { + pgstat_send_inquiry(file_min_ts); + pg_usleep(PGSTAT_POLL_RETRY_DELAY * 1000); + } + } + + if (!stats_ready) + elog(WARNING, "pgstat wait timeout"); + /* Autovacuum launcher wants stats about all databases */ if (IsAutoVacuumLauncherProcess()) pgStatDBHash = pgstat_read_statsfile(InvalidOid, false); *************** *** 3779,3781 **** --- 3835,3851 ---- HASH_REMOVE, NULL); } } + + /* ---------- + * pgstat_recv_inquiry() - + * + * Process stat inquiry requests. + * ---------- + */ + static void + pgstat_recv_inquiry(PgStat_MsgInquiry *msg, int len) + { + if (msg->inquiry_time > last_statrequest) + last_statrequest = msg->inquiry_time; + } + Index: src/include/pgstat.h =================================================================== RCS file: /projects/cvsroot/pgsql/src/include/pgstat.h,v retrieving revision 1.78 diff -c -r1.78 pgstat.h *** src/include/pgstat.h 15 Aug 2008 08:37:40 -0000 1.78 --- src/include/pgstat.h 8 Sep 2008 21:00:20 -0000 *************** *** 42,48 **** PGSTAT_MTYPE_ANALYZE, PGSTAT_MTYPE_BGWRITER, PGSTAT_MTYPE_FUNCSTAT, ! PGSTAT_MTYPE_FUNCPURGE } StatMsgType; /* ---------- --- 42,49 ---- PGSTAT_MTYPE_ANALYZE, PGSTAT_MTYPE_BGWRITER, PGSTAT_MTYPE_FUNCSTAT, ! PGSTAT_MTYPE_FUNCPURGE, ! PGSTAT_MTYPE_INQUIRY } StatMsgType; /* ---------- *************** *** 385,390 **** --- 386,404 ---- /* ---------- + * PgStat_MsgInquiry Sent by the backend to tell the collector + * to write the stats file. + * ---------- + */ + + typedef struct PgStat_MsgInquiry + { + PgStat_MsgHdr m_hdr; + TimestampTz inquiry_time; + } PgStat_MsgInquiry; + + + /* ---------- * PgStat_Msg Union over all possible messages. * ---------- */ *************** *** 402,407 **** --- 416,422 ---- PgStat_MsgBgWriter msg_bgwriter; PgStat_MsgFuncstat msg_funcstat; PgStat_MsgFuncpurge msg_funcpurge; + PgStat_MsgInquiry msg_inquiry; } PgStat_Msg; *************** *** 413,419 **** * ------------------------------------------------------------ */ ! #define PGSTAT_FILE_FORMAT_ID 0x01A5BC97 /* ---------- * PgStat_StatDBEntry The collector's data per database --- 428,434 ---- * ------------------------------------------------------------ */ ! #define PGSTAT_FILE_FORMAT_ID 0x01A5BC98 /* ---------- * PgStat_StatDBEntry The collector's data per database