The sixth chapter of PostgreSQL Replication Monitoring your settings (3)

6.3 Checking the operating system process

Once we have checked the archive and our system view, we are ready to check the system process. Checking the system process may look a bit rough, but it proves to be very effective.

On master, we can simply check a process called Wal_sender. On slave we want to check for a process called wal_receiver.

Let's first examine what we should see on master:

9314?? Ss 0:00.00 Postgres:wal Sender Process

HS:: 1 (61498) idle

On Linux we can see that the process not only has its own role (in this case, Wal_sender), but also comes with the name of the end user and the associated network connection information. In our example we can see that someone has already connected to master from a local port via 61498.

The situation on the slave is fairly simple:

9313?? Ss 0:00.00 Postgres:wal Receiver Process

All we see is a process that tells us that we are consuming xlog.

If there are two processes here, you've got a good indicator and your copy setup works well.

The sixth chapter of PostgreSQL Replication Monitoring your settings (3)