From e81427ad6da4bac608d188180569abe02914013e Mon Sep 17 00:00:00 2001 From: Nitin Jadhav Date: Sun, 22 Sep 2024 17:04:23 +0530 Subject: [PATCH] Fix inconsistency in reporting checkpointer stats. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The information about buffers written, which is revealed through the pg_stat_checkpointer view, has been found to be inconsistent with the data in the checkpoint complete log message. To address this, a new column named ‘slru_written’ has been added to the pg_stat_checkpointer view. This column displays the SLRU buffers written during checkpoints. The existing ‘buffers_written’ column continues to represent the main buffers written during checkpoints. Furthermore, the information about buffers written, which is logged in the checkpoint complete log message, includes both the main buffer count and the SLRU buffer count. This patch distinguishes between these two types of information. --- doc/src/sgml/monitoring.sgml | 9 +++++++ src/backend/access/transam/slru.c | 7 +++-- src/backend/access/transam/xlog.c | 26 ++++++++++--------- src/backend/catalog/system_views.sql | 1 + .../utils/activity/pgstat_checkpointer.c | 2 ++ src/backend/utils/adt/pgstatfuncs.c | 6 +++++ src/include/access/xlog.h | 1 + src/include/catalog/pg_proc.dat | 5 ++++ src/include/pgstat.h | 1 + src/test/regress/expected/rules.out | 1 + 10 files changed, 45 insertions(+), 14 deletions(-) diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml index a2fda4677d..6cbbb1ca5c 100644 --- a/doc/src/sgml/monitoring.sgml +++ b/doc/src/sgml/monitoring.sgml @@ -3125,6 +3125,15 @@ description | Waiting for a newly initialized WAL file to reach durable storage + + + slru_written bigint + + + Number of SLRU buffers written during checkpoints and restartpoints + + + stats_reset timestamp with time zone diff --git a/src/backend/access/transam/slru.c b/src/backend/access/transam/slru.c index e7f73bf427..bf8deccdc0 100644 --- a/src/backend/access/transam/slru.c +++ b/src/backend/access/transam/slru.c @@ -716,9 +716,12 @@ SlruInternalWritePage(SlruCtl ctl, int slotno, SlruWriteAll fdata) if (!ok) SlruReportIOError(ctl, pageno, InvalidTransactionId); - /* If part of a checkpoint, count this as a buffer written. */ + /* If part of a checkpoint, count this as a slru written. */ if (fdata) - CheckpointStats.ckpt_bufs_written++; + { + CheckpointStats.ckpt_slru_written++; + PendingCheckpointerStats.slru_written++; + } } /* diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 853ab06812..d9f25a9046 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -6727,14 +6727,15 @@ LogCheckpointEnd(bool restartpoint) */ if (restartpoint) ereport(LOG, - (errmsg("restartpoint complete: wrote %d buffers (%.1f%%); " - "%d WAL file(s) added, %d removed, %d recycled; " - "write=%ld.%03d s, sync=%ld.%03d s, total=%ld.%03d s; " - "sync files=%d, longest=%ld.%03d s, average=%ld.%03d s; " - "distance=%d kB, estimate=%d kB; " - "lsn=%X/%X, redo lsn=%X/%X", + (errmsg("restartpoint complete: wrote %d buffers (%.1f%%), " + "wrote %d slru buffers; %d WAL file(s) added, " + "%d removed, %d recycled; write=%ld.%03d s, " + "sync=%ld.%03d s, total=%ld.%03d s; sync files=%d, " + "longest=%ld.%03d s, average=%ld.%03d s; distance=%d kB, " + "estimate=%d kB; lsn=%X/%X, redo lsn=%X/%X", CheckpointStats.ckpt_bufs_written, (double) CheckpointStats.ckpt_bufs_written * 100 / NBuffers, + CheckpointStats.ckpt_slru_written, CheckpointStats.ckpt_segs_added, CheckpointStats.ckpt_segs_removed, CheckpointStats.ckpt_segs_recycled, @@ -6750,14 +6751,15 @@ LogCheckpointEnd(bool restartpoint) LSN_FORMAT_ARGS(ControlFile->checkPointCopy.redo)))); else ereport(LOG, - (errmsg("checkpoint complete: wrote %d buffers (%.1f%%); " - "%d WAL file(s) added, %d removed, %d recycled; " - "write=%ld.%03d s, sync=%ld.%03d s, total=%ld.%03d s; " - "sync files=%d, longest=%ld.%03d s, average=%ld.%03d s; " - "distance=%d kB, estimate=%d kB; " - "lsn=%X/%X, redo lsn=%X/%X", + (errmsg("checkpoint complete: wrote %d buffers (%.1f%%), " + "wrote %d slru buffers; %d WAL file(s) added, " + "%d removed, %d recycled; write=%ld.%03d s, " + "sync=%ld.%03d s, total=%ld.%03d s; sync files=%d, " + "longest=%ld.%03d s, average=%ld.%03d s; distance=%d kB, " + "estimate=%d kB; lsn=%X/%X, redo lsn=%X/%X", CheckpointStats.ckpt_bufs_written, (double) CheckpointStats.ckpt_bufs_written * 100 / NBuffers, + CheckpointStats.ckpt_slru_written, CheckpointStats.ckpt_segs_added, CheckpointStats.ckpt_segs_removed, CheckpointStats.ckpt_segs_recycled, diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql index 7fd5d256a1..a12db38d45 100644 --- a/src/backend/catalog/system_views.sql +++ b/src/backend/catalog/system_views.sql @@ -1144,6 +1144,7 @@ CREATE VIEW pg_stat_checkpointer AS pg_stat_get_checkpointer_write_time() AS write_time, pg_stat_get_checkpointer_sync_time() AS sync_time, pg_stat_get_checkpointer_buffers_written() AS buffers_written, + pg_stat_get_checkpointer_slru_written() AS slru_written, pg_stat_get_checkpointer_stat_reset_time() AS stats_reset; CREATE VIEW pg_stat_io AS diff --git a/src/backend/utils/activity/pgstat_checkpointer.c b/src/backend/utils/activity/pgstat_checkpointer.c index bbfc9c7e18..21fda77276 100644 --- a/src/backend/utils/activity/pgstat_checkpointer.c +++ b/src/backend/utils/activity/pgstat_checkpointer.c @@ -55,6 +55,7 @@ pgstat_report_checkpointer(void) CHECKPOINTER_ACC(write_time); CHECKPOINTER_ACC(sync_time); CHECKPOINTER_ACC(buffers_written); + CHECKPOINTER_ACC(slru_written); #undef CHECKPOINTER_ACC pgstat_end_changecount_write(&stats_shmem->changecount); @@ -133,5 +134,6 @@ pgstat_checkpointer_snapshot_cb(void) CHECKPOINTER_COMP(write_time); CHECKPOINTER_COMP(sync_time); CHECKPOINTER_COMP(buffers_written); + CHECKPOINTER_COMP(slru_written); #undef CHECKPOINTER_COMP } diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c index 9c23ac7c8c..58d72e4361 100644 --- a/src/backend/utils/adt/pgstatfuncs.c +++ b/src/backend/utils/adt/pgstatfuncs.c @@ -1215,6 +1215,12 @@ pg_stat_get_checkpointer_buffers_written(PG_FUNCTION_ARGS) PG_RETURN_INT64(pgstat_fetch_stat_checkpointer()->buffers_written); } +Datum +pg_stat_get_checkpointer_slru_written(PG_FUNCTION_ARGS) +{ + PG_RETURN_INT64(pgstat_fetch_stat_checkpointer()->slru_written); +} + Datum pg_stat_get_bgwriter_buf_written_clean(PG_FUNCTION_ARGS) { diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index 083810f5b4..5296be3d6c 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -167,6 +167,7 @@ typedef struct CheckpointStatsData TimestampTz ckpt_end_t; /* end of checkpoint */ int ckpt_bufs_written; /* # of buffers written */ + int ckpt_slru_written; /* # of SLRU buffers written */ int ckpt_segs_added; /* # of new xlog segments created */ int ckpt_segs_removed; /* # of xlog segments deleted */ diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index 43f608d7a0..0eb6e5c57b 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -5839,6 +5839,11 @@ proname => 'pg_stat_get_checkpointer_buffers_written', provolatile => 's', proparallel => 'r', prorettype => 'int8', proargtypes => '', prosrc => 'pg_stat_get_checkpointer_buffers_written' }, +{ oid => '3814', + descr => 'statistics: number of SLRU buffers written during checkpoints and restartpoints', + proname => 'pg_stat_get_checkpointer_slru_written', provolatile => 's', + proparallel => 'r', prorettype => 'int8', proargtypes => '', + prosrc => 'pg_stat_get_checkpointer_slru_written' }, { oid => '6314', descr => 'statistics: last reset for the checkpointer', proname => 'pg_stat_get_checkpointer_stat_reset_time', provolatile => 's', proparallel => 'r', prorettype => 'timestamptz', proargtypes => '', diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 4752dfe719..ea437f4273 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -300,6 +300,7 @@ typedef struct PgStat_CheckpointerStats PgStat_Counter write_time; /* times in milliseconds */ PgStat_Counter sync_time; PgStat_Counter buffers_written; + PgStat_Counter slru_written; TimestampTz stat_reset_timestamp; } PgStat_CheckpointerStats; diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out index a1626f3fae..322e24d16a 100644 --- a/src/test/regress/expected/rules.out +++ b/src/test/regress/expected/rules.out @@ -1830,6 +1830,7 @@ pg_stat_checkpointer| SELECT pg_stat_get_checkpointer_num_timed() AS num_timed, pg_stat_get_checkpointer_write_time() AS write_time, pg_stat_get_checkpointer_sync_time() AS sync_time, pg_stat_get_checkpointer_buffers_written() AS buffers_written, + pg_stat_get_checkpointer_slru_written() AS slru_written, pg_stat_get_checkpointer_stat_reset_time() AS stats_reset; pg_stat_database| SELECT oid AS datid, datname, -- 2.25.1