diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml index f3bf527d5b4..cbfc29c0642 100644 --- a/doc/src/sgml/monitoring.sgml +++ b/doc/src/sgml/monitoring.sgml @@ -320,6 +320,20 @@ postgres 27093 0.0 0.0 30096 2752 ? Ss 11:34 0:00 postgres: ser + + + pg_stat_backend_transaction + pg_stat_backend_transaction + + + One row per server process, showing statistics related to + the current activity of that process, such as number of commits and + rollbacks. + See + pg_stat_backend_transaction for details. + + + pg_stat_replicationpg_stat_replication One row per WAL sender process, showing statistics about @@ -1172,6 +1186,91 @@ description | Waiting for a newly initialized WAL file to reach durable storage + + <structname>pg_stat_backend_transaction</structname> + + + pg_stat_backend_transaction + + + + The pg_stat_backend_transaction view will have one row + per server process, showing statistics related to + the current activity of that process. + + + + <structname>pg_stat_backend_transaction</structname> View + + + + + Column Type + + + Description + + + + + + + + pid integer + + + Process ID of this backend + + + + + + xid_count bigint + + + The number of XID that have been generated by the backend. It does not take + into account virtual transaction ID on purpose. + + + + + + xact_commit bigint + + + The number of transactions that have been committed. + + + + + + xact_rollback bigint + + + The number of transactions that have been rolled back. + + + + + + stats_reset timestamp with time zone + + + Time at which these statistics were last reset + + + + +
+ + + + The view does not return statistics for the checkpointer, + the background writer, the startup process and the autovacuum launcher. + + + + <structname>pg_stat_replication</structname> @@ -4990,6 +5089,22 @@ description | Waiting for a newly initialized WAL file to reach durable storage + + + + pg_stat_get_backend_transactions + + pg_stat_get_backend_transactions ( integer ) + setof record + + + Returns a record of transaction statistics about the backend with the + specified process ID, or one record for each active backend in the system + if NULL is specified. The fields returned are a + subset of those in the pg_stat_backend_transaction view. + + + diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql index dec8df4f8ee..4d74d9719b2 100644 --- a/src/backend/catalog/system_views.sql +++ b/src/backend/catalog/system_views.sql @@ -925,6 +925,15 @@ CREATE VIEW pg_stat_activity AS LEFT JOIN pg_database AS D ON (S.datid = D.oid) LEFT JOIN pg_authid AS U ON (S.usesysid = U.oid); +CREATE VIEW pg_stat_backend_transaction AS + SELECT + S.pid, + S.xid_count, + S.xact_commit, + S.xact_rollback, + S.stats_reset + FROM pg_stat_get_backend_transactions(NULL) AS S; + CREATE VIEW pg_stat_replication AS SELECT S.pid, diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 199ba2cc17a..dec7e5b6234 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -37,7 +37,7 @@ * reported within critical sections so we use static memory in order to avoid * memory allocation. */ -static PgStat_BackendPending PendingBackendStats; +PgStat_BackendPending PendingBackendStats; static bool backend_has_iostats = false; /* @@ -48,6 +48,11 @@ static bool backend_has_iostats = false; */ static WalUsage prevBackendWalUsage; +/* + * For backend commit and rollback statistics. + */ +bool backend_has_xactstats = false; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -261,6 +266,36 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref) prevBackendWalUsage = pgWalUsage; } +/* + * Flush out locally pending backend transaction statistics. Locking is managed + * by the caller. + */ +static void +pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) +{ + PgStatShared_Backend *shbackendent; + + /* + * This function can be called even if nothing at all has happened for + * transaction statistics. In this case, avoid unnecessarily modifying + * the stats entry. + */ + if (!backend_has_xactstats) + return; + + shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats; + + shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; + shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; + + PendingBackendStats.pending_xact_commit = 0; + PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; + + backend_has_xactstats = false; +} + /* * Flush out locally pending backend statistics * @@ -285,6 +320,10 @@ pgstat_flush_backend(bool nowait, bits32 flags) pgstat_backend_wal_have_pending()) has_pending_data = true; + /* Some transaction data pending? */ + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + has_pending_data = true; + if (!has_pending_data) return false; @@ -300,6 +339,9 @@ pgstat_flush_backend(bool nowait, bits32 flags) if (flags & PGSTAT_BACKEND_FLUSH_WAL) pgstat_flush_backend_entry_wal(entry_ref); + if (flags & PGSTAT_BACKEND_FLUSH_XACT) + pgstat_flush_backend_entry_xact(entry_ref); + pgstat_unlock_entry(entry_ref); return false; diff --git a/src/backend/utils/activity/pgstat_database.c b/src/backend/utils/activity/pgstat_database.c index b31f20d41bc..400a8c5d734 100644 --- a/src/backend/utils/activity/pgstat_database.c +++ b/src/backend/utils/activity/pgstat_database.c @@ -342,6 +342,13 @@ pgstat_update_dbstats(TimestampTz ts) dbentry->blk_read_time += pgStatBlockReadTime; dbentry->blk_write_time += pgStatBlockWriteTime; + /* Do the same for backend stats */ + PendingBackendStats.pending_xact_commit += pgStatXactCommit; + PendingBackendStats.pending_xact_rollback += pgStatXactRollback; + + backend_has_xactstats = true; + pgstat_report_fixed = true; + if (pgstat_should_report_connstat()) { long secs; diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c index a710508979e..ccc996e8b8c 100644 --- a/src/backend/utils/adt/pgstatfuncs.c +++ b/src/backend/utils/adt/pgstatfuncs.c @@ -706,6 +706,63 @@ pg_stat_get_activity(PG_FUNCTION_ARGS) return (Datum) 0; } +/* + * Returns statistics of PG backends. + */ +Datum +pg_stat_get_backend_transactions(PG_FUNCTION_ARGS) +{ +#define PG_STAT_GET_BACKEND_STATS_COLS 5 + int num_backends = pgstat_fetch_stat_numbackends(); + int curr_backend; + int pid = PG_ARGISNULL(0) ? -1 : PG_GETARG_INT32(0); + ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo; + + InitMaterializedSRF(fcinfo, 0); + + /* 1-based index */ + for (curr_backend = 1; curr_backend <= num_backends; curr_backend++) + { + /* for each row */ + Datum values[PG_STAT_GET_BACKEND_STATS_COLS] = {0}; + bool nulls[PG_STAT_GET_BACKEND_STATS_COLS] = {0}; + LocalPgBackendStatus *local_beentry; + PgBackendStatus *beentry; + PgStat_Backend *backend_stats; + + /* Get the next one in the list */ + local_beentry = pgstat_get_local_beentry_by_index(curr_backend); + beentry = &local_beentry->backendStatus; + + /* If looking for specific PID, ignore all the others */ + if (pid != -1 && beentry->st_procpid != pid) + continue; + + backend_stats = pgstat_fetch_stat_backend_by_pid(beentry->st_procpid, NULL); + + values[0] = Int32GetDatum(beentry->st_procpid); + + if (!backend_stats) + continue; + + values[1] = Int64GetDatum(backend_stats->xid_count); + values[2] = Int64GetDatum(backend_stats->xact_commit); + values[3] = Int64GetDatum(backend_stats->xact_rollback); + + if (backend_stats->stat_reset_timestamp != 0) + values[4] = TimestampTzGetDatum(backend_stats->stat_reset_timestamp); + else + nulls[4] = true; + + tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls); + + /* If only a single backend was requested, and we found it, break. */ + if (pid != -1) + break; + } + + return (Datum) 0; +} Datum pg_backend_pid(PG_FUNCTION_ARGS) diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index 9121a382f76..2fdfa321a3c 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -5657,6 +5657,15 @@ proargmodes => '{i,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o}', proargnames => '{pid,datid,pid,usesysid,application_name,state,query,wait_event_type,wait_event,xact_start,query_start,backend_start,state_change,client_addr,client_hostname,client_port,backend_xid,backend_xmin,backend_type,ssl,sslversion,sslcipher,sslbits,ssl_client_dn,ssl_client_serial,ssl_issuer_dn,gss_auth,gss_princ,gss_enc,gss_delegation,leader_pid,query_id}', prosrc => 'pg_stat_get_activity' }, +{ oid => '9555', + descr => 'statistics: statistics about currently active backends', + proname => 'pg_stat_get_backend_transactions', prorows => '100', proisstrict => 'f', + proretset => 't', provolatile => 's', proparallel => 'r', + prorettype => 'record', proargtypes => 'int4', + proallargtypes => '{int4,int4,int8,int8,int8,timestamptz}', + proargmodes => '{i,o,o,o,o,o}', + proargnames => '{pid,pid,xid_count,xact_commit,xact_rollback,stats_reset}', + prosrc => 'pg_stat_get_backend_transactions' }, { oid => '6318', descr => 'describe wait events', proname => 'pg_get_wait_events', procost => '10', prorows => '250', proretset => 't', provolatile => 'v', prorettype => 'record', diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 7ae503e71a2..602ce45afb9 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -496,6 +496,9 @@ typedef struct PgStat_Backend TimestampTz stat_reset_timestamp; PgStat_BktypeIO io_stats; PgStat_WalCounters wal_counters; + PgStat_Counter xact_commit; + PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -508,6 +511,13 @@ typedef struct PgStat_BackendPending * Backend statistics store the same amount of IO data as PGSTAT_KIND_IO. */ PgStat_PendingIO pending_io; + + /* + * Transaction statistics pending flush. + */ + PgStat_Counter pending_xact_commit; + PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* @@ -807,6 +817,13 @@ extern PGDLLIMPORT int pgstat_track_functions; extern PGDLLIMPORT int pgstat_fetch_consistency; +/* + * Variables in pgstat_backend.c + */ + +extern PGDLLIMPORT PgStat_BackendPending PendingBackendStats; +extern PGDLLIMPORT bool backend_has_xactstats; + /* * Variables in pgstat_bgwriter.c */ diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h index 4d2b8aa6081..7ed4cbe4eda 100644 --- a/src/include/utils/pgstat_internal.h +++ b/src/include/utils/pgstat_internal.h @@ -647,7 +647,8 @@ extern void pgstat_archiver_snapshot_cb(void); /* flags for pgstat_flush_backend() */ #define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */ #define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */ -#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL) +#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */ +#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT) extern bool pgstat_flush_backend(bool nowait, bits32 flags); extern bool pgstat_backend_flush_cb(bool nowait); diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out index 77e25ca029e..e2d87415cc7 100644 --- a/src/test/regress/expected/rules.out +++ b/src/test/regress/expected/rules.out @@ -1857,6 +1857,12 @@ pg_stat_archiver| SELECT archived_count, last_failed_time, stats_reset FROM pg_stat_get_archiver() s(archived_count, last_archived_wal, last_archived_time, failed_count, last_failed_wal, last_failed_time, stats_reset); +pg_stat_backend_transaction| SELECT pid, + xid_count, + xact_commit, + xact_rollback, + stats_reset + FROM pg_stat_get_backend_transactions(NULL::integer) s(pid, xid_count, xact_commit, xact_rollback, stats_reset); pg_stat_bgwriter| SELECT pg_stat_get_bgwriter_buf_written_clean() AS buffers_clean, pg_stat_get_bgwriter_maxwritten_clean() AS maxwritten_clean, pg_stat_get_buf_alloc() AS buffers_alloc, diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out index 67e1860e984..ca599f98643 100644 --- a/src/test/regress/expected/stats.out +++ b/src/test/regress/expected/stats.out @@ -135,11 +135,28 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES; INSERT INTO trunc_stats_test1 DEFAULT VALUES; UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2); DELETE FROM trunc_stats_test1 WHERE id = 3; +-- in passing, check that backend's commit is incrementing +SELECT xact_commit AS xact_commit_before + FROM pg_stat_backend_transaction WHERE pid = pg_backend_pid() \gset BEGIN; UPDATE trunc_stats_test1 SET id = id + 100; TRUNCATE trunc_stats_test1; INSERT INTO trunc_stats_test1 DEFAULT VALUES; COMMIT; +SELECT pg_stat_force_next_flush(); + pg_stat_force_next_flush +-------------------------- + +(1 row) + +SELECT xact_commit AS xact_commit_after + FROM pg_stat_backend_transaction WHERE pid = pg_backend_pid() \gset +SELECT :xact_commit_after > :xact_commit_before; + ?column? +---------- + t +(1 row) + -- use a savepoint: 1 insert, 1 live BEGIN; INSERT INTO trunc_stats_test2 DEFAULT VALUES; diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql index 8768e0f27fd..558b7bfb972 100644 --- a/src/test/regress/sql/stats.sql +++ b/src/test/regress/sql/stats.sql @@ -58,12 +58,22 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES; UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2); DELETE FROM trunc_stats_test1 WHERE id = 3; +-- in passing, check that backend's commit is incrementing +SELECT xact_commit AS xact_commit_before + FROM pg_stat_backend_transaction WHERE pid = pg_backend_pid() \gset + BEGIN; UPDATE trunc_stats_test1 SET id = id + 100; TRUNCATE trunc_stats_test1; INSERT INTO trunc_stats_test1 DEFAULT VALUES; COMMIT; +SELECT pg_stat_force_next_flush(); +SELECT xact_commit AS xact_commit_after + FROM pg_stat_backend_transaction WHERE pid = pg_backend_pid() \gset + +SELECT :xact_commit_after > :xact_commit_before; + -- use a savepoint: 1 insert, 1 live BEGIN; INSERT INTO trunc_stats_test2 DEFAULT VALUES;