pgpool_adm

Overview

Pgpool-II/PGDG package 4.7.3; pgpool_adm SQL/control version 1.6. Verified RPM/DEB payload includes pgpool_adm.so; standard native extension, no preload required.

Version

Install

You can install pgpool directly. First, make sure the PGDG repository is added and enabled:

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

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

pig install pgpool;          # Install for current active PG version

pig ext install -y pgpool -v 18  # PG 18
pig ext install -y pgpool -v 17  # PG 17
pig ext install -y pgpool -v 16  # PG 16
pig ext install -y pgpool -v 15  # PG 15
pig ext install -y pgpool -v 14  # PG 14

dnf install -y pgpool-II-pg18-extensions       # PG 18
dnf install -y pgpool-II-pg17-extensions       # PG 17
dnf install -y pgpool-II-pg16-extensions       # PG 16
dnf install -y pgpool-II-pg15-extensions       # PG 15
dnf install -y pgpool-II-pg14-extensions       # PG 14

apt install -y postgresql-18-pgpool2   # PG 18
apt install -y postgresql-17-pgpool2   # PG 17
apt install -y postgresql-16-pgpool2   # PG 16
apt install -y postgresql-15-pgpool2   # PG 15
apt install -y postgresql-14-pgpool2   # PG 14

Create Extension:

CREATE EXTENSION pgpool_adm;

Usage

Sources:

• Pgpool-II 4.7.3 control
• SQL API 1.6
• PCP node reference
• Foreign-server setup

pgpool_adm exposes SQL wrappers for Pgpool-II PCP administration. A reachable Pgpool-II PCP service and appropriate PCP credentials are required; installing the extension does not deploy Pgpool-II.

Install and Inspect a Node

CREATE EXTENSION pgpool_adm;

SELECT * FROM pcp_node_info(
  node_id => 0, host => 'localhost', port => 9898,
  username => 'pcp_admin', password => 'example-password');
SELECT pcp_node_count(
  host => 'localhost', port => 9898,
  username => 'pcp_admin', password => 'example-password');

The actual SQL names are pcp_node_info, pcp_health_check_stats, pcp_pool_status, pcp_node_count, pcp_attach_node, pcp_detach_node, and pcp_proc_info. The documentation page names may carry a package prefix; that prefix is not part of these SQL functions.

Credential and Server References

The direct overload accepts host, port, username and password, with node ID first where required. Other overloads accept a foreign-server reference through the pcp_server argument. Configure that server and user mapping according to the source implementation; do not assume a client-side .pcppass file supplies credentials to the database backend.

SELECT * FROM pcp_node_info(node_id => 0, pcp_server => 'pgpool_server');
SELECT pcp_node_count(pcp_server => 'pgpool_server');

The usual PCP port is 9898. Credential handling and network access occur on the PostgreSQL server. Literal passwords can enter SQL logs and activity views; prefer the configured server-reference path where suitable.

Manage Nodes

SELECT pcp_detach_node(
  node_id => 1, gracefully => true,
  host => 'localhost', port => 9898,
  username => 'pcp_admin', password => 'example-password');
SELECT pcp_attach_node(
  node_id => 1, host => 'localhost', port => 9898,
  username => 'pcp_admin', password => 'example-password');

Detaching or attaching nodes changes Pgpool-II routing and can affect application traffic. Restrict function access and PCP credentials to administrators. A database transaction rollback does not undo an external PCP operation.

Version and Loading

Have a superuser install the extension. It needs no preload or PostgreSQL restart. Pgpool-II package release 4.7.3 ships SQL extension version 1.6; update existing databases using ALTER EXTENSION pgpool_adm UPDATE after installing matching files, rather than specifying 4.7.3 as an SQL version.