What is repmgr?
repmgr is an open-source tool suite for managing replication and failover in a cluster of PostgreSQL servers. It enhances PostgreSQL's built-in hot-standby capabilities with tools to set up standby servers, monitor replication, and perform administrative tasks such as failover or manual switchover operations.
repmgr has provided advanced support for PostgreSQL's built-in replication mechanisms since they were introduced in 9.0. The current repmgr series, repmgr 4, supports the latest developments in replication functionality introduced from PostgreSQL 9.3 such as cascading replication, timeline switching and base backups via the replication protocol.
Open Source from 2ndQuadrant
repmgr is developed by 2ndQuadrant, the global experts in PostgreSQL support, training, development, migration and consultancy.
repmgr is free and open-source software licensed under the GNU Public License (GPL) v3. This means you are free to use and modify repmgr as you see fit, however any modifications you make may only be distributed under the same terms. See here for details.
Contributions to repmgr are welcome. See the CONTRIBUTING.md file for information about how to contribute.
Comprehensive online documentation is available in DocBook format at https://repmgr.org/docs/4.0/index.html.
From version 4.0, repmgr is implemented as a full PostgreSQL extension; upgrading to future releases will be performed by the standard extension upgrade mechanism. For more details see the documentation and check the release notes for each version.
Upgrading from repmgr 3 to repmgr 4
Full instructions for upgrading repmgr 3.x installations to repmgr 4 are provided here: Upgrading from repmgr 3.x
Upgrading repmgr 3.x
Upgrading between minor releases (e.g. 3.0.2 to 3.0.3) is straightforward and requires only an upgrade of the installed repmgr version.
For some releases, an update of repmgr's internal database is required; this is straightforward and requires an SQL script to be applied to the database. If your version upgrade skips one or more releases, you'll need to apply the script for each skipped release sequentially beginning with the oldest.
Currently, database upgrades are required between the following versions:
- repmgr 3.1.1 to repmgr 3.1.2: release notes.
- repmgr 3.0 to repmgr 3.1: release notes.
- repmgr 2.0 to repmgr 3.0: release notes.
See the release notes for each version for details.
Instructions for uninstalling repmgr can be found here.