pgsentinel
pgsentinel
pgsentinel : active session history
Overview
| ID | Extension | Package | Version | Category | License | Language |
|---|---|---|---|---|---|---|
| 6410 | pgsentinel | pgsentinel | 1.4.1 | STAT | PostgreSQL | C |
| Attribute | Has Binary | Has Library | Need Load | Has DDL | Relocatable | Trusted |
|---|---|---|---|---|---|---|
--sLd-r | No | Yes | Yes | Yes | yes | no |
| Relationships | |
|---|---|
| See Also | system_stats pgnodemx pg_stat_monitor pg_wait_sampling bgw_replstatus pg_profile pg_proctab powa |
Packages
| Type | Repo | Version | PG Major Compatibility | Package Pattern | Dependencies |
|---|---|---|---|---|---|
| EXT | MIXED | 1.4.1 | 18 17 16 15 14 | pgsentinel | - |
| RPM | PIGSTY | 1.4.1 | 18 17 16 15 14 | pgsentinel_$v | - |
| DEB | PGDG | 1.4.1 | 18 17 16 15 14 | postgresql-$v-pgsentinel | - |
| Linux / PG | PG18 | PG17 | PG16 | PG15 | PG14 |
|---|---|---|---|---|---|
el8.x86_64 | PIGSTY 1.4.1 | PIGSTY 1.4.1 | PIGSTY 1.4.1 | PIGSTY 1.4.1 | PIGSTY 1.4.1 |
el8.aarch64 | PIGSTY 1.4.1 | PIGSTY 1.4.1 | PIGSTY 1.4.1 | PIGSTY 1.4.1 | PIGSTY 1.4.1 |
el9.x86_64 | PIGSTY 1.4.1 | PIGSTY 1.4.1 | PIGSTY 1.4.1 | PIGSTY 1.4.1 | PIGSTY 1.4.1 |
el9.aarch64 | PIGSTY 1.4.1 | PIGSTY 1.4.1 | PIGSTY 1.4.1 | PIGSTY 1.4.1 | PIGSTY 1.4.1 |
el10.x86_64 | PIGSTY 1.4.1 | PIGSTY 1.4.1 | PIGSTY 1.4.1 | PIGSTY 1.4.1 | PIGSTY 1.4.1 |
el10.aarch64 | PIGSTY 1.4.1 | PIGSTY 1.4.1 | PIGSTY 1.4.1 | PIGSTY 1.4.1 | PIGSTY 1.4.1 |
d12.x86_64 | PGDG 1.4.1 | PGDG 1.4.1 | PGDG 1.4.1 | PGDG 1.4.1 | PGDG 1.4.1 |
d12.aarch64 | PGDG 1.4.1 | PGDG 1.4.1 | PGDG 1.4.1 | PGDG 1.4.1 | PGDG 1.4.1 |
d13.x86_64 | PGDG 1.4.1 | PGDG 1.4.1 | PGDG 1.4.1 | PGDG 1.4.1 | PGDG 1.4.1 |
d13.aarch64 | PGDG 1.4.1 | PGDG 1.4.1 | PGDG 1.4.1 | PGDG 1.4.1 | PGDG 1.4.1 |
u22.x86_64 | PGDG 1.4.1 | PGDG 1.4.1 | PGDG 1.4.1 | PGDG 1.4.1 | PGDG 1.4.1 |
u22.aarch64 | PGDG 1.4.1 | PGDG 1.4.1 | PGDG 1.4.1 | PGDG 1.4.1 | PGDG 1.4.1 |
u24.x86_64 | PGDG 1.4.1 | PGDG 1.4.1 | PGDG 1.4.1 | PGDG 1.4.1 | PGDG 1.4.1 |
u24.aarch64 | PGDG 1.4.1 | PGDG 1.4.1 | PGDG 1.4.1 | PGDG 1.4.1 | PGDG 1.4.1 |
Source
pig build pkg pgsentinel; # build rpm/debInstall
Make sure PGDG and PIGSTY repo available:
pig repo add pgsql -u # add both repo and update cacheInstall this extension with pig:
pig install pgsentinel; # install via package name, for the active PG version
pig install pgsentinel -v 18; # install for PG 18
pig install pgsentinel -v 17; # install for PG 17
pig install pgsentinel -v 16; # install for PG 16
pig install pgsentinel -v 15; # install for PG 15
pig install pgsentinel -v 14; # install for PG 14Config this extension to shared_preload_libraries:
shared_preload_libraries = 'pgsentinel';Create this extension with:
CREATE EXTENSION pgsentinel;Usage
pgsentinel records active session history by sampling pg_stat_activity at regular intervals and linking activity with pg_stat_statements query statistics.
Active Session History
SELECT ash_time, datname, usename, pid, state,
wait_event_type, wait_event, query, queryid
FROM pg_active_session_history
ORDER BY ash_time DESC;Key columns beyond pg_stat_activity:
| Column | Description |
|---|---|
ash_time | Sampling timestamp |
top_level_query | Top-level statement (for PL/pgSQL) |
query | Statement with actual parameter values |
cmdtype | Statement type: SELECT, UPDATE, INSERT, DELETE, UTILITY, UNKNOWN, NOTHING |
queryid | Links to pg_stat_statements |
blockers | Number of blocking processes |
blockerpid | PID of a blocking process |
blocker_state | State of the blocker |
Query Statistics History
When enabled, pgsentinel also samples pg_stat_statements concurrently:
SELECT ash_time, queryid, calls, total_exec_time, rows,
shared_blks_hit, shared_blks_read
FROM pg_stat_statements_history
ORDER BY ash_time DESC;Example: Wait Analysis
-- Top wait events in the last hour
SELECT wait_event_type, wait_event, count(*)
FROM pg_active_session_history
WHERE ash_time > now() - interval '1 hour'
AND wait_event IS NOT NULL
GROUP BY 1, 2
ORDER BY 3 DESC;
-- Blocking analysis
SELECT blockerpid, blocker_state, count(*)
FROM pg_active_session_history
WHERE blockers > 0
GROUP BY 1, 2
ORDER BY 3 DESC;Configuration
| Parameter | Default | Description |
|---|---|---|
pgsentinel_ash.sampling_period | 1 | Sampling period in seconds |
pgsentinel_ash.max_entries | 1000 | Ring buffer size for ASH |
pgsentinel.db_name | postgres | Database for worker connection |
pgsentinel_ash.track_idle_trans | false | Track idle-in-transaction sessions |
pgsentinel_pgssh.max_entries | 1000 | Ring buffer for pg_stat_statements history |
pgsentinel_pgssh.enable | false | Enable pg_stat_statements history |
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