pg_datasentinel

Overview

shared_preload_libraries = pg_datasentinel is required because the extension allocates shared memory and hooks into activity logging.

Version

Build

You can build the RPM / DEB packages for pg_datasentinel using pig build:

pig build pkg pg_datasentinel         # build RPM / DEB packages

Install

You can install pg_datasentinel directly. First, make sure the PGDG and PIGSTY repositories are added and enabled:

pig repo add pgsql -u          # Add repo and update cache

Install the extension using pig or apt/yum/dnf:

• Install
• pig
• dnf
• apt

pig install pg_datasentinel;          # Install for current active PG version

pig ext install -y pg_datasentinel -v 18  # PG 18
pig ext install -y pg_datasentinel -v 17  # PG 17
pig ext install -y pg_datasentinel -v 16  # PG 16
pig ext install -y pg_datasentinel -v 15  # PG 15

dnf install -y pg_datasentinel_18       # PG 18
dnf install -y pg_datasentinel_17       # PG 17
dnf install -y pg_datasentinel_16       # PG 16
dnf install -y pg_datasentinel_15       # PG 15

apt install -y postgresql-18-pg-datasentinel   # PG 18
apt install -y postgresql-17-pg-datasentinel   # PG 17
apt install -y postgresql-16-pg-datasentinel   # PG 16
apt install -y postgresql-15-pg-datasentinel   # PG 15

Preload:

shared_preload_libraries = 'pg_datasentinel';

Create Extension:

CREATE EXTENSION pg_datasentinel;

Usage

Source: README, Release 1.0

pg_datasentinel adds observability views on top of PostgreSQL activity, maintenance, temporary-file, checkpoint, wraparound, and container resource data. It must be preloaded because it allocates shared memory and hooks into activity logging.

Required setup

-- postgresql.conf
shared_preload_libraries = 'pg_datasentinel'
log_autovacuum_min_duration = 0
log_temp_files = 0
log_checkpoints = on

CREATE EXTENSION pg_datasentinel;

Main views

• ds_stat_activity: extends pg_stat_activity with backend RSS, optional PSS, temp-file bytes, and plan_id on PostgreSQL 18+.
• ds_container_resources: reports cgroup CPU and memory limits plus current usage.
• ds_wraparound_risk: estimates XID and MXID ETA to aggressive vacuum and wraparound from hourly snapshots.
• ds_xid_snapshots: raw snapshot history used by ds_wraparound_risk.
• ds_vacuum_activity, ds_analyze_activity, ds_tempfile_activity, ds_checkpoint_activity: shared-memory ring buffers for maintenance and checkpoint events.
• ds_activity_summary: one-row summary of ring-buffer occupancy and timestamps.

Useful GUCs

• pg_datasentinel.enabled: enables or disables capture.
• pg_datasentinel.max_entries: ring-buffer capacity per activity stream; restart required.
• pg_datasentinel.maintenance_force_verbose: adds VERBOSE to manual VACUUM and ANALYZE so they are captured.
• pg_datasentinel.ignore_system_schemas: suppresses pg_catalog and information_schema noise.
• pg_datasentinel.enable_pss_memory: reads /proc/*/smaps_rollup for per-backend PSS.

Caveats

• PostgreSQL 15+ is required upstream.
• Memory and temp-file enrichment depends on Linux /proc; container metrics depend on cgroups.
• Vacuum and analyze parsing depends on English log keywords, so translated server message locales are not fully supported.
• plan_id is only populated on PostgreSQL 18+, and is most useful when paired with the official pg_store_plans fork linked from the README.