Some built-in tools deserve a special mention. The pg_receivexlog command was introduced with PostgreSQL 9.2. With this utility, PostgreSQL can transmit transaction logs to a remote system without the need for a dedicated PostgreSQL server. This also means that we can avoid ad hoc tools such as rsync when maintaining an archive server to save old WAL files.
This allows us to set up any server to pull transaction logs directly from the primary PostgreSQL server. For highly available servers, PostgreSQL no longer needs to fork an external command to safeguard transaction logs into an archive location. Also, we can monitor the state of the transmission through the pg_stat_replication system view.
In effect, we remove quite a bit of overhead from our PostgreSQL server and offload it to a less sensitive system. This recipe will provide a quick...