MongoDB Administrator's Guide

How it works...

As mentioned earlier, this recipe assumes that you are already running the first (primary) node in your replica set, as show in the previous recipe. In step 1, we start another instance of mongod listening on a different port (27018). I just want to reiterate that as this is a test setup we will be running all instances of mongod on the same server, but in a production setup all replica set members should be running on separate servers.

In step 2, we look at the output of the rs.status() command, more importantly the members array. As of now, although we have started a new instance, the primary replica set node is not aware of its existence. Therefore, the list of members would only show one member. Let's fix this.

In step ...