Add some instrumentation to the bgwriter, through the stats collector.

New view pg_stat_bgwriter, and the functions required to build it.

3 files changed, 56 insertions, 5 deletions

diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h
index 270687b153..aa0e29a216 100644
--- a/src/include/catalog/catversion.h
+++ b/src/include/catalog/catversion.h
@@ -37,7 +37,7 @@
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.396 2007/03/27 23:21:11 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.397 2007/03/30 18:34:56 mha Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	200703271
+#define CATALOG_VERSION_NO	200703301
 
 #endif
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index 44e585e9c4..713d76fbfa 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.451 2007/03/27 23:21:11 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.452 2007/03/30 18:34:56 mha Exp $
  *
  * NOTES
  *	  The script catalog/genbki.sh reads this file and generates .bki
@@ -2987,6 +2987,20 @@ DATA(insert OID = 2761 (  pg_stat_get_db_tuples_updated PGNSP PGUID 12 1 0 f f t
 DESCR("Statistics: Tuples updated in database");
 DATA(insert OID = 2762 (  pg_stat_get_db_tuples_deleted PGNSP PGUID 12 1 0 f f t f s 1 20 "26" _null_ _null_ _null_ pg_stat_get_db_tuples_deleted - _null_ ));
 DESCR("Statistics: Tuples deleted in database");
+DATA(insert OID = 2769 ( pg_stat_get_bgwriter_timed_checkpoints PGNSP PGUID 12 1 0 f f t f s 0 20 "" _null_ _null_ _null_ pg_stat_get_bgwriter_timed_checkpoints - _null_ ));
+DESCR("Statistics: Number of timed checkpoints started by the bgwriter");
+DATA(insert OID = 2770 ( pg_stat_get_bgwriter_requested_checkpoints PGNSP PGUID 12 1 0 f f t f s 0 20 "" _null_ _null_ _null_ pg_stat_get_bgwriter_requested_checkpoints - _null_ ));
+DESCR("Statistics: Number of backend requested checkpoints started by the bgwriter");
+DATA(insert OID = 2771 ( pg_stat_get_bgwriter_buf_written_checkpoints PGNSP PGUID 12 1 0 f f t f s 0 20 "" _null_ _null_ _null_ pg_stat_get_bgwriter_buf_written_checkpoints - _null_ ));
+DESCR("Statistics: Number of buffers written by the bgwriter during checkpoints");
+DATA(insert OID = 2772 ( pg_stat_get_bgwriter_buf_written_lru PGNSP PGUID 12 1 0 f f t f s 0 20 "" _null_ _null_ _null_ pg_stat_get_bgwriter_buf_written_lru - _null_ ));
+DESCR("Statistics: Number of buffers written by the bgwriter during LRU scans");
+DATA(insert OID = 2773 ( pg_stat_get_bgwriter_buf_written_all PGNSP PGUID 12 1 0 f f t f s 0 20 "" _null_ _null_ _null_ pg_stat_get_bgwriter_buf_written_all - _null_ ));
+DESCR("Statistics: Number of buffers written by the bgwriter during all-buffer scans");
+DATA(insert OID = 2774 ( pg_stat_get_bgwriter_maxwritten_lru PGNSP PGUID 12 1 0 f f t f s 0 20 "" _null_ _null_ _null_ pg_stat_get_bgwriter_maxwritten_lru - _null_ ));
+DESCR("Statistics: Number of times the bgwriter stopped processing when it had written too many buffers during LRU scans");
+DATA(insert OID = 2775 ( pg_stat_get_bgwriter_maxwritten_all PGNSP PGUID 12 1 0 f f t f s 0 20 "" _null_ _null_ _null_ pg_stat_get_bgwriter_maxwritten_all - _null_ ));
+DESCR("Statistics: Number of times the bgwriter stopped processing when it had written too many buffers during all-buffer scans");
 DATA(insert OID = 2230 (  pg_stat_clear_snapshot		PGNSP PGUID 12 1 0 f f f f v 0 2278  "" _null_ _null_ _null_	pg_stat_clear_snapshot - _null_ ));
 DESCR("Statistics: Discard current transaction's statistics snapshot");
 DATA(insert OID = 2274 (  pg_stat_reset					PGNSP PGUID 12 1 0 f f f f v 0 2278  "" _null_ _null_ _null_	pg_stat_reset - _null_ ));
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 8e08db4c17..3cfcea7e4b 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -5,7 +5,7 @@
  *
  *	Copyright (c) 2001-2007, PostgreSQL Global Development Group
  *
- *	$PostgreSQL: pgsql/src/include/pgstat.h,v 1.56 2007/03/22 19:53:31 momjian Exp $
+ *	$PostgreSQL: pgsql/src/include/pgstat.h,v 1.57 2007/03/30 18:34:55 mha Exp $
  * ----------
  */
 #ifndef PGSTAT_H
@@ -30,7 +30,8 @@ typedef enum StatMsgType
 	PGSTAT_MTYPE_RESETCOUNTER,
 	PGSTAT_MTYPE_AUTOVAC_START,
 	PGSTAT_MTYPE_VACUUM,
-	PGSTAT_MTYPE_ANALYZE
+	PGSTAT_MTYPE_ANALYZE,
+	PGSTAT_MTYPE_BGWRITER
 } StatMsgType;
 
 /* ----------
@@ -213,6 +214,24 @@ typedef struct PgStat_MsgAnalyze
 
 
 /* ----------
+ * PgStat_MsgBgWriter           Sent by the bgwriter to update statistics.
+ * ----------
+ */
+typedef struct PgStat_MsgBgWriter
+{
+	PgStat_MsgHdr m_hdr;
+
+	PgStat_Counter  m_timed_checkpoints;
+	PgStat_Counter	m_requested_checkpoints;
+	PgStat_Counter	m_buf_written_checkpoints;
+	PgStat_Counter	m_buf_written_lru;
+	PgStat_Counter	m_buf_written_all;
+	PgStat_Counter	m_maxwritten_lru;
+	PgStat_Counter	m_maxwritten_all;
+} PgStat_MsgBgWriter;
+
+
+/* ----------
  * PgStat_Msg					Union over all possible messages.
  * ----------
  */
@@ -227,6 +246,7 @@ typedef union PgStat_Msg
 	PgStat_MsgAutovacStart msg_autovacuum;
 	PgStat_MsgVacuum msg_vacuum;
 	PgStat_MsgAnalyze msg_analyze;
+	PgStat_MsgBgWriter msg_bgwriter;
 } PgStat_Msg;
 
 
@@ -297,6 +317,21 @@ typedef struct PgStat_StatTabEntry
 } PgStat_StatTabEntry;
 
 
+/*
+ * Global statistics kept in the stats collector
+ */
+typedef struct PgStat_GlobalStats
+{
+	PgStat_Counter  timed_checkpoints;
+	PgStat_Counter  requested_checkpoints;
+	PgStat_Counter  buf_written_checkpoints;
+	PgStat_Counter  buf_written_lru;
+	PgStat_Counter  buf_written_all;
+	PgStat_Counter  maxwritten_lru;
+	PgStat_Counter  maxwritten_all;
+} PgStat_GlobalStats;
+
+
 /* ----------
  * Shared-memory data structures
  * ----------
@@ -478,6 +513,7 @@ extern void pgstat_initstats(PgStat_Info *stats, Relation rel);
 
 extern void pgstat_count_xact_commit(void);
 extern void pgstat_count_xact_rollback(void);
+extern void pgstat_send_bgwriter(void);
 
 /* ----------
  * Support functions for the SQL-callable functions to
@@ -488,5 +524,6 @@ extern PgStat_StatDBEntry *pgstat_fetch_stat_dbentry(Oid dbid);
 extern PgStat_StatTabEntry *pgstat_fetch_stat_tabentry(Oid relid);
 extern PgBackendStatus *pgstat_fetch_stat_beentry(int beid);
 extern int	pgstat_fetch_stat_numbackends(void);
+extern PgStat_GlobalStats *pgstat_fetch_global(void);
 
 #endif   /* PGSTAT_H */