diff --git a/src/backend/postmaster/autovacuum.c b/src/backend/postmaster/autovacuum.c
index d98f47f9b7..e9e7ae3691 100644
--- a/src/backend/postmaster/autovacuum.c
+++ b/src/backend/postmaster/autovacuum.c
@@ -10,7 +10,7 @@
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/postmaster/autovacuum.c,v 1.15 2006/03/07 17:32:22 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/postmaster/autovacuum.c,v 1.16 2006/04/06 20:38:00 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -384,19 +384,7 @@ AutoVacMain(int argc, char *argv[])
continue;
/*
- * Don't try to access a database that was dropped. This could only
- * happen if we read the pg_database flat file right before it was
- * modified, after the database was dropped from the pg_database
- * table. (This is of course a not-very-bulletproof test, but it's
- * cheap to make. If we do mistakenly choose a recently dropped
- * database, InitPostgres will fail and we'll drop out until the next
- * autovac run.)
- */
- if (tmp->entry->destroy != 0)
- continue;
-
- /*
- * Else remember the db with oldest autovac time.
+ * Remember the db with oldest autovac time.
*/
if (db == NULL ||
tmp->entry->last_autovac_time < db->entry->last_autovac_time)
@@ -417,6 +405,9 @@ AutoVacMain(int argc, char *argv[])
/*
* Connect to the selected database
+ *
+ * Note: if we have selected a just-deleted database (due to using
+ * stale stats info), we'll fail and exit here.
*/
InitPostgres(db->name, NULL);
SetProcessingMode(NormalProcessing);
diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
index d8c0e5e20f..cfd3997409 100644
--- a/src/backend/postmaster/pgstat.c
+++ b/src/backend/postmaster/pgstat.c
@@ -13,7 +13,7 @@
*
* Copyright (c) 2001-2006, PostgreSQL Global Development Group
*
- * $PostgreSQL: pgsql/src/backend/postmaster/pgstat.c,v 1.121 2006/03/05 15:58:36 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/postmaster/pgstat.c,v 1.122 2006/04/06 20:38:00 tgl Exp $
* ----------
*/
#include "postgres.h"
@@ -69,12 +69,6 @@
#define PGSTAT_STAT_INTERVAL 500 /* How often to write the status file;
* in milliseconds. */
-#define PGSTAT_DESTROY_DELAY 10000 /* How long to keep destroyed objects
- * known, to give delayed UDP packets
- * time to arrive; in milliseconds. */
-
-#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. */
@@ -141,7 +135,6 @@ static int pgStatXactRollback = 0;
static TransactionId pgStatDBHashXact = InvalidTransactionId;
static HTAB *pgStatDBHash = NULL;
-static HTAB *pgStatBeDead = NULL;
static PgStat_StatBeEntry *pgStatBeTable = NULL;
static int pgStatNumBackends = 0;
@@ -1552,7 +1545,6 @@ PgstatCollectorMain(int argc, char *argv[])
int readPipe;
int len = 0;
struct itimerval timeout;
- HASHCTL hash_ctl;
bool need_timer = false;
MyProcPid = getpid(); /* reset MyProcPid */
@@ -1614,16 +1606,6 @@ PgstatCollectorMain(int argc, char *argv[])
pgStatRunningInCollector = true;
pgstat_read_statsfile(&pgStatDBHash, InvalidOid, NULL, NULL);
- /*
- * Create the dead backend hashtable
- */
- memset(&hash_ctl, 0, sizeof(hash_ctl));
- hash_ctl.keysize = sizeof(int);
- hash_ctl.entrysize = sizeof(PgStat_StatBeDead);
- hash_ctl.hash = tag_hash;
- pgStatBeDead = hash_create("Dead Backends", PGSTAT_BE_HASH_SIZE,
- &hash_ctl, HASH_ELEM | HASH_FUNCTION);
-
/*
* Create the known backends table
*/
@@ -2085,7 +2067,6 @@ static int
pgstat_add_backend(PgStat_MsgHdr *msg)
{
PgStat_StatBeEntry *beentry;
- PgStat_StatBeDead *deadbe;
/*
* Check that the backend ID is valid
@@ -2111,32 +2092,13 @@ pgstat_add_backend(PgStat_MsgHdr *msg)
if (beentry->procpid > 0 && beentry->procpid == msg->m_procpid)
return 0;
- /*
- * Lookup if this backend is known to be dead. This can be caused due to
- * messages arriving in the wrong order - e.g. postmaster's BETERM message
- * might have arrived before we received all the backends stats messages,
- * or even a new backend with the same backendid was faster in sending his
- * BESTART.
- *
- * If the backend is known to be dead, we ignore this add.
- */
- deadbe = (PgStat_StatBeDead *) hash_search(pgStatBeDead,
- (void *) &(msg->m_procpid),
- HASH_FIND, NULL);
- if (deadbe)
- return 1;
-
- /*
- * Backend isn't known to be dead. If it's slot is currently used, we have
- * to kick out the old backend.
- */
- if (beentry->procpid > 0)
- pgstat_sub_backend(beentry->procpid);
-
/* Must be able to distinguish between empty and non-empty slots */
Assert(msg->m_procpid > 0);
- /* Put this new backend into the slot */
+ /*
+ * Put this new backend into the slot (possibly overwriting an old entry,
+ * if we missed its BETERM or the BETERM hasn't arrived yet).
+ */
beentry->procpid = msg->m_procpid;
beentry->start_timestamp = GetCurrentTimestamp();
beentry->activity_start_timestamp = 0;
@@ -2185,7 +2147,6 @@ pgstat_get_db_entry(Oid databaseid, bool create)
result->n_xact_rollback = 0;
result->n_blocks_fetched = 0;
result->n_blocks_hit = 0;
- result->destroy = 0;
result->last_autovac_time = 0;
memset(&hash_ctl, 0, sizeof(hash_ctl));
@@ -2211,8 +2172,6 @@ static void
pgstat_sub_backend(int procpid)
{
int i;
- PgStat_StatBeDead *deadbe;
- bool found;
/*
* Search in the known-backends table for the slot containing this PID.
@@ -2222,28 +2181,7 @@ pgstat_sub_backend(int procpid)
if (pgStatBeTable[i].procpid == procpid)
{
/*
- * That's him. Add an entry to the known to be dead backends. Due
- * to possible misorder in the arrival of UDP packets it's
- * possible that even if we know the backend is dead, there could
- * still be messages queued that arrive later. Those messages must
- * not cause our number of backends statistics to get screwed up,
- * so we remember for a couple of seconds that this PID is dead
- * and ignore them (only the counting of backends, not the table
- * access stats they sent).
- */
- deadbe = (PgStat_StatBeDead *) hash_search(pgStatBeDead,
- (void *) &procpid,
- HASH_ENTER,
- &found);
-
- if (!found)
- {
- deadbe->backendid = i + 1;
- deadbe->destroy = PGSTAT_DESTROY_COUNT;
- }
-
- /*
- * Declare the backend slot empty.
+ * That's him. Mark the backend slot empty.
*/
pgStatBeTable[i].procpid = 0;
return;
@@ -2270,7 +2208,6 @@ pgstat_write_statsfile(void)
HASH_SEQ_STATUS tstat;
PgStat_StatDBEntry *dbentry;
PgStat_StatTabEntry *tabentry;
- PgStat_StatBeDead *deadbe;
FILE *fpout;
int i;
int32 format_id;
@@ -2300,31 +2237,6 @@ pgstat_write_statsfile(void)
hash_seq_init(&hstat, pgStatDBHash);
while ((dbentry = (PgStat_StatDBEntry *) hash_seq_search(&hstat)) != NULL)
{
- /*
- * If this database is marked destroyed, count down and do so if it
- * reaches 0.
- */
- if (dbentry->destroy > 0)
- {
- if (--(dbentry->destroy) == 0)
- {
- if (dbentry->tables != NULL)
- hash_destroy(dbentry->tables);
-
- if (hash_search(pgStatDBHash,
- (void *) &(dbentry->databaseid),
- HASH_REMOVE, NULL) == NULL)
- ereport(ERROR,
- (errmsg("database hash table corrupted "
- "during cleanup --- abort")));
- }
-
- /*
- * Don't include statistics for it.
- */
- continue;
- }
-
/*
* Write out the DB entry including the number of live backends.
* We don't write the tables pointer since it's of no use to any
@@ -2339,30 +2251,6 @@ pgstat_write_statsfile(void)
hash_seq_init(&tstat, dbentry->tables);
while ((tabentry = (PgStat_StatTabEntry *) hash_seq_search(&tstat)) != NULL)
{
- /*
- * If table entry marked for destruction, same as above for the
- * database entry.
- */
- if (tabentry->destroy > 0)
- {
- if (--(tabentry->destroy) == 0)
- {
- if (hash_search(dbentry->tables,
- (void *) &(tabentry->tableid),
- HASH_REMOVE, NULL) == NULL)
- ereport(ERROR,
- (errmsg("tables hash table for "
- "database %u corrupted during "
- "cleanup --- abort",
- dbentry->databaseid)));
- }
- continue;
- }
-
- /*
- * At least we think this is still a live table. Emit its access
- * stats.
- */
fputc('T', fpout);
fwrite(tabentry, sizeof(PgStat_StatTabEntry), 1, fpout);
}
@@ -2428,26 +2316,6 @@ pgstat_write_statsfile(void)
PGSTAT_STAT_TMPFILE, PGSTAT_STAT_FILENAME)));
unlink(PGSTAT_STAT_TMPFILE);
}
-
- /*
- * Clear out the dead backends table
- */
- hash_seq_init(&hstat, pgStatBeDead);
- while ((deadbe = (PgStat_StatBeDead *) hash_seq_search(&hstat)) != NULL)
- {
- /*
- * Count down the destroy delay and remove entries where it reaches 0.
- */
- if (--(deadbe->destroy) <= 0)
- {
- if (hash_search(pgStatBeDead,
- (void *) &(deadbe->procpid),
- HASH_REMOVE, NULL) == NULL)
- ereport(ERROR,
- (errmsg("dead-server-process hash table corrupted "
- "during cleanup --- abort")));
- }
- }
}
/*
@@ -2595,7 +2463,6 @@ pgstat_read_statsfile(HTAB **dbhash, Oid onlydb,
memcpy(dbentry, &dbbuf, sizeof(PgStat_StatDBEntry));
dbentry->tables = NULL;
- dbentry->destroy = 0;
dbentry->n_backends = 0;
/*
@@ -3005,12 +2872,8 @@ pgstat_recv_tabstat(PgStat_MsgTabstat *msg, int len)
dbentry = pgstat_get_db_entry(msg->m_databaseid, true);
/*
- * If the database is marked for destroy, this is a delayed UDP packet and
- * not worth being counted.
+ * Update database-wide stats.
*/
- if (dbentry->destroy > 0)
- return;
-
dbentry->n_xact_commit += (PgStat_Counter) (msg->m_xact_commit);
dbentry->n_xact_rollback += (PgStat_Counter) (msg->m_xact_rollback);
@@ -3043,8 +2906,6 @@ pgstat_recv_tabstat(PgStat_MsgTabstat *msg, int len)
tabentry->blocks_fetched = tabmsg[i].t_blocks_fetched;
tabentry->blocks_hit = tabmsg[i].t_blocks_hit;
-
- tabentry->destroy = 0;
}
else
{
@@ -3085,7 +2946,6 @@ static void
pgstat_recv_tabpurge(PgStat_MsgTabpurge *msg, int len)
{
PgStat_StatDBEntry *dbentry;
- PgStat_StatTabEntry *tabentry;
int i;
/*
@@ -3102,23 +2962,15 @@ pgstat_recv_tabpurge(PgStat_MsgTabpurge *msg, int len)
if (!dbentry || !dbentry->tables)
return;
- /*
- * If the database is marked for destroy, this is a delayed UDP packet and
- * the tables will go away at DB destruction.
- */
- if (dbentry->destroy > 0)
- return;
-
/*
* Process all table entries in the message.
*/
for (i = 0; i < msg->m_nentries; i++)
{
- tabentry = (PgStat_StatTabEntry *) hash_search(dbentry->tables,
- (void *) &(msg->m_tableid[i]),
- HASH_FIND, NULL);
- if (tabentry)
- tabentry->destroy = PGSTAT_DESTROY_COUNT;
+ /* Remove from hashtable if present; we don't care if it's not. */
+ (void) hash_search(dbentry->tables,
+ (void *) &(msg->m_tableid[i]),
+ HASH_REMOVE, NULL);
}
}
@@ -3146,10 +2998,20 @@ pgstat_recv_dropdb(PgStat_MsgDropdb *msg, int len)
dbentry = pgstat_get_db_entry(msg->m_databaseid, false);
/*
- * Mark the database for destruction.
+ * If found, remove it.
*/
if (dbentry)
- dbentry->destroy = PGSTAT_DESTROY_COUNT;
+ {
+ if (dbentry->tables != NULL)
+ hash_destroy(dbentry->tables);
+
+ if (hash_search(pgStatDBHash,
+ (void *) &(dbentry->databaseid),
+ HASH_REMOVE, NULL) == NULL)
+ ereport(ERROR,
+ (errmsg("database hash table corrupted "
+ "during cleanup --- abort")));
+ }
}
@@ -3191,7 +3053,6 @@ pgstat_recv_resetcounter(PgStat_MsgResetcounter *msg, int len)
dbentry->n_xact_rollback = 0;
dbentry->n_blocks_fetched = 0;
dbentry->n_blocks_hit = 0;
- dbentry->destroy = 0;
memset(&hash_ctl, 0, sizeof(hash_ctl));
hash_ctl.keysize = sizeof(Oid);
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 2442559b21..00631b3e12 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -5,7 +5,7 @@
*
* Copyright (c) 2001-2006, PostgreSQL Global Development Group
*
- * $PostgreSQL: pgsql/src/include/pgstat.h,v 1.42 2006/03/05 15:58:53 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/pgstat.h,v 1.43 2006/04/06 20:38:00 tgl Exp $
* ----------
*/
#ifndef PGSTAT_H
@@ -271,16 +271,18 @@ typedef union PgStat_Msg
* ------------------------------------------------------------
*/
-#define PGSTAT_FILE_FORMAT_ID 0x01A5BC94
+#define PGSTAT_FILE_FORMAT_ID 0x01A5BC95
/* ----------
* PgStat_StatDBEntry The collector's data per database
+ *
+ * Note: n_backends is not maintained within the collector. It's computed
+ * when a backend reads the stats file for use.
* ----------
*/
typedef struct PgStat_StatDBEntry
{
Oid databaseid;
- int destroy;
int n_backends;
PgStat_Counter n_xact_commit;
PgStat_Counter n_xact_rollback;
@@ -325,24 +327,6 @@ typedef struct PgStat_StatBeEntry
} PgStat_StatBeEntry;
-/* ----------
- * PgStat_StatBeDead Because UDP packets can arrive out of
- * order, we need to keep some information
- * about backends that are known to be
- * dead for some seconds. This info is held
- * in a hash table of these structs.
- *
- * (This struct is not used in the stats file.)
- * ----------
- */
-typedef struct PgStat_StatBeDead
-{
- int procpid;
- int backendid;
- int destroy;
-} PgStat_StatBeDead;
-
-
/* ----------
* PgStat_StatTabEntry The collector's data per table (or index)
* ----------
@@ -350,7 +334,6 @@ typedef struct PgStat_StatBeDead
typedef struct PgStat_StatTabEntry
{
Oid tableid;
- int destroy;
PgStat_Counter numscans;