pgpool_recovery

recovery functions for pgpool-II for V4.3

pgpool : recovery functions for pgpool-II for V4.3

Overview

ID	Extension	Package	Version	Category	License	Language
5910	pgpool_recovery	pgpool	`4.7.2`	ADMIN	PostgreSQL	C

Attribute	Has Binary	Has Library	Need Load	Has DDL	Relocatable	Trusted
----d--	No	No	No	Yes	no	no

Relationships
See Also	pgautofailover repmgr pg_failover_slots bgw_replstatus pglogical pgactive pglogical_ticker
Siblings	pgpool_adm pgpool_regclass

Packages

Type	Repo	Version	PG Major Compatibility	Package Pattern	Dependencies
EXT	PGDG	`4.7.2`	18 17 16 15 14	`pgpool`	-
RPM	PGDG	`4.7.2`	18 17 16 15 14	`pgpool-II-pg$v-extensions`	-
DEB	PGDG	`4.7.2`	18 17 16 15 14	`postgresql-$v-pgpool2`	-

Linux / PG	PG18	PG17	PG16	PG15	PG14
el8.x86_64	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2
el8.aarch64	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2
el9.x86_64	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2
el9.aarch64	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2
el10.x86_64	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2
el10.aarch64	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2
d12.x86_64	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2
d12.aarch64	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2
d13.x86_64	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2
d13.aarch64	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2
u22.x86_64	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2
u22.aarch64	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2
u24.x86_64	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2
u24.aarch64	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2
u26.x86_64	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2
u26.aarch64	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2

Source

Repository

pgpool.net/

Install

Make sure PGDG repo available:

pig repo add pgdg -u    # add pgdg repo and update cache

Install this extension with pig:

pig install pgpool;		# install via package name, for the active PG version
pig install pgpool_recovery;		# install by extension name, for the current active PG version

pig install pgpool_recovery -v 18;   # install for PG 18
pig install pgpool_recovery -v 17;   # install for PG 17
pig install pgpool_recovery -v 16;   # install for PG 16
pig install pgpool_recovery -v 15;   # install for PG 15
pig install pgpool_recovery -v 14;   # install for PG 14

Create this extension with:

CREATE EXTENSION pgpool_recovery;

Usage

pgpool_recovery: recovery functions for pgpool-II

The pgpool_recovery extension provides recovery-related functions used by Pgpool-II for online recovery of backend PostgreSQL nodes.

Functions

-- Trigger online recovery of a backend node
-- Executes the recovery script on the primary node
SELECT pgpool_recovery(
    'recovery_1st_stage_script',   -- script name in $PGDATA
    'target_hostname',             -- hostname of node to recover
    'target_pgdata',               -- data directory on target
    'target_port'                  -- port number on target
);

-- Second stage recovery (optional, for streaming replication)
SELECT pgpool_remote_start(
    'target_hostname',             -- hostname of recovered node
    'target_pgdata'                -- data directory on target
);

-- Check if the target node is ready
SELECT pgpool_pgctl('status', 'target_pgdata');

How It Works

Pgpool-II calls pgpool_recovery() on the primary node, which executes a user-defined shell script to perform base backup and setup
The recovery script copies data to the target node and configures replication
pgpool_remote_start() starts the recovered PostgreSQL instance
Pgpool-II attaches the recovered node back into the pool

Recovery Scripts

The recovery script (e.g., recovery_1st_stage) must be placed in the primary node’s $PGDATA directory. It typically performs:

pg_basebackup to copy data to the target
Configuration of primary_conninfo for streaming replication
Creation of standby.signal on the target

The extension must be installed on all PostgreSQL backend nodes managed by Pgpool-II.