repmgr – simplified management of replication, failover, & switchover for PostgreSQL clusters
repmgr is the most popular tool for PostgreSQL replication and failover management. repmgr simplifies administration and daily management, enhances productivity and complements built-in replication capabilities in PostgreSQL.
Introduced by 2ndQuadrant in 2010, repmgr takes advantage of PostgreSQL’s Hot Standby capability and greatly simplifies the process of setting up and managing databases with high availability and scalability requirements.
repmgr is available via 2ndQuadrant’s YUM repository for the Red Hat family (RHEL, CentOS, and Fedora) and PGDG’s APT repository for Debian (please use the test repository for the Beta version – more details at the installation instruction link below). You can use standard yum and apt package managers for installing repmgr with your instance of PostgreSQL.
The images and explanation below represent some of the most common configurations of repmgr in production databases.
1 Primary + 1 Standby
Here, repmgr is configured on Standby for failover in case the Primary node fails.
1 Primary + 2 Standbys
Here, repmgr is configured on 2 Standby nodes for failover in case the Primary node fails. Additional Standby node is configured for High Availability (HA) so at least one Standby is still present after failover.
1 Primary + 3 Standbys + 1 Witness
Here, the Standby in Location B is a last resort in case Location A becomes entirely unavailable. The Witness server here ensures that in case of network interruption between the two locations, the Standby at Location B does not promote itself to Primary, i.e. prevents the Split Brain scenario.
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. Click here for details.
Need more help?
Want to know even more? Need some help to implement repmgr? As the developers we’re the best people in the world to help you get up and running with repmgr. We have consultants available to provide assistance, plus our unique 24/7 Production Support subscription service also covers repmgr.