From PostgreSQL wiki
repmgr is an open source package which greatly simplifies the process of setting up and managing replication using streaming replication within a cluster of PostgreSQL servers.
repmgr 2, released in 2014, is available for PostgreSQL 9.0 ~ 9.4.
repmgr 3, released in 2015, is available PostgreSQL 9.3 and later and supports newer replication features such as timeline switching, cascading standbys and replication slots.
- standby cloning with pg_basebackup or optionally rsync
- Timeline following
- a standby can be promoted to a master without requiring a restart
- other standbys can connect to the new master without being resynced
- Cascading standby support
- Standbys not directly connected to the master node are not affected during failover of the master to another standby mode
- Replication slot support (PostgreSQL 9.4 and later), simplifying WAL retention management
See: www.repmgr.org for details and downloads.