From 37009b778e83a1f4d6d5365d0ab90db2daa62176 Mon Sep 17 00:00:00 2001 From: Bertrand Drouvot Date: Wed, 20 Nov 2024 08:35:13 +0000 Subject: [PATCH v4] Add a write_to_file member to PgStat_KindInfo This new member allows the statistics to configure whether or not they want to be written to the file on disk. That gives more flexiblity to the custom statistics. --- src/backend/utils/activity/pgstat.c | 21 +++++++++++++++++-- src/include/utils/pgstat_internal.h | 3 +++ .../injection_points/injection_stats.c | 1 + .../injection_points/injection_stats_fixed.c | 1 + 4 files changed, 24 insertions(+), 2 deletions(-) 87.2% src/backend/utils/activity/ 6.9% src/include/utils/ 5.8% src/test/modules/injection_points/ diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c index ea8c5691e8..01f82279bf 100644 --- a/src/backend/utils/activity/pgstat.c +++ b/src/backend/utils/activity/pgstat.c @@ -12,7 +12,8 @@ * Statistics are loaded from the filesystem during startup (by the startup * process), unless preceded by a crash, in which case all stats are * discarded. They are written out by the checkpointer process just before - * shutting down, except when shutting down in immediate mode. + * shutting down (if the statistics kind allow it), except when shutting down in + * immediate mode. * * Fixed-numbered stats are stored in plain (non-dynamic) shared memory. * @@ -281,6 +282,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE] .name = "database", .fixed_amount = false, + .write_to_file = true, /* so pg_stat_database entries can be seen in all databases */ .accessed_across_databases = true, @@ -297,6 +299,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE] .name = "relation", .fixed_amount = false, + .write_to_file = true, .shared_size = sizeof(PgStatShared_Relation), .shared_data_off = offsetof(PgStatShared_Relation, stats), @@ -311,6 +314,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE] .name = "function", .fixed_amount = false, + .write_to_file = true, .shared_size = sizeof(PgStatShared_Function), .shared_data_off = offsetof(PgStatShared_Function, stats), @@ -324,6 +328,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE] .name = "replslot", .fixed_amount = false, + .write_to_file = true, .accessed_across_databases = true, @@ -340,6 +345,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE] .name = "subscription", .fixed_amount = false, + .write_to_file = true, /* so pg_stat_subscription_stats entries can be seen in all databases */ .accessed_across_databases = true, @@ -359,6 +365,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE] .name = "archiver", .fixed_amount = true, + .write_to_file = true, .snapshot_ctl_off = offsetof(PgStat_Snapshot, archiver), .shared_ctl_off = offsetof(PgStat_ShmemControl, archiver), @@ -374,6 +381,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE] .name = "bgwriter", .fixed_amount = true, + .write_to_file = true, .snapshot_ctl_off = offsetof(PgStat_Snapshot, bgwriter), .shared_ctl_off = offsetof(PgStat_ShmemControl, bgwriter), @@ -389,6 +397,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE] .name = "checkpointer", .fixed_amount = true, + .write_to_file = true, .snapshot_ctl_off = offsetof(PgStat_Snapshot, checkpointer), .shared_ctl_off = offsetof(PgStat_ShmemControl, checkpointer), @@ -404,6 +413,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE] .name = "io", .fixed_amount = true, + .write_to_file = true, .snapshot_ctl_off = offsetof(PgStat_Snapshot, io), .shared_ctl_off = offsetof(PgStat_ShmemControl, io), @@ -421,6 +431,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE] .name = "slru", .fixed_amount = true, + .write_to_file = true, .snapshot_ctl_off = offsetof(PgStat_Snapshot, slru), .shared_ctl_off = offsetof(PgStat_ShmemControl, slru), @@ -438,6 +449,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE] .name = "wal", .fixed_amount = true, + .write_to_file = true, .snapshot_ctl_off = offsetof(PgStat_Snapshot, wal), .shared_ctl_off = offsetof(PgStat_ShmemControl, wal), @@ -1611,7 +1623,8 @@ pgstat_write_statsfile(XLogRecPtr redo) char *ptr; const PgStat_KindInfo *info = pgstat_get_kind_info(kind); - if (!info || !info->fixed_amount) + /* skip if not fixed or this kind does not want to write to the file */ + if (!info || !info->fixed_amount || !info->write_to_file) continue; if (pgstat_is_kind_builtin(kind)) @@ -1663,6 +1676,10 @@ pgstat_write_statsfile(XLogRecPtr redo) /* if not dropped the valid-entry refcount should exist */ Assert(pg_atomic_read_u32(&ps->refcount) > 0); + /* skip if this kind does not want to write to the file */ + if (!kind_info->write_to_file) + continue; + if (!kind_info->to_serialized_name) { /* normal stats entry, identified by PgStat_HashKey */ diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h index 437db06910..57ac6e87b6 100644 --- a/src/include/utils/pgstat_internal.h +++ b/src/include/utils/pgstat_internal.h @@ -213,6 +213,9 @@ typedef struct PgStat_KindInfo */ bool accessed_across_databases:1; + /* Write or not to the file */ + bool write_to_file:1; + /* * The size of an entry in the shared stats hash table (pointed to by * PgStatShared_HashEntry->body). For fixed-numbered statistics, this is diff --git a/src/test/modules/injection_points/injection_stats.c b/src/test/modules/injection_points/injection_stats.c index d89d055913..e16b9db284 100644 --- a/src/test/modules/injection_points/injection_stats.c +++ b/src/test/modules/injection_points/injection_stats.c @@ -39,6 +39,7 @@ static bool injection_stats_flush_cb(PgStat_EntryRef *entry_ref, bool nowait); static const PgStat_KindInfo injection_stats = { .name = "injection_points", .fixed_amount = false, /* Bounded by the number of points */ + .write_to_file = true, /* Injection points are system-wide */ .accessed_across_databases = true, diff --git a/src/test/modules/injection_points/injection_stats_fixed.c b/src/test/modules/injection_points/injection_stats_fixed.c index 2fed178b7a..c5b0bb8cf0 100644 --- a/src/test/modules/injection_points/injection_stats_fixed.c +++ b/src/test/modules/injection_points/injection_stats_fixed.c @@ -50,6 +50,7 @@ static void injection_stats_fixed_snapshot_cb(void); static const PgStat_KindInfo injection_stats_fixed = { .name = "injection_points_fixed", .fixed_amount = true, + .write_to_file = true, .shared_size = sizeof(PgStat_StatInjFixedEntry), .shared_data_off = offsetof(PgStatShared_InjectionPointFixed, stats), -- 2.34.1