Step 1: Setting up HAProxy

I hope you gone through [Part1] (https://viggy28.dev/article/postgres-active-active-replication/) of this series. Perhaps, one thing you might have noticed is that I’ve to connect to the specific master database. In our case, since both the databases are running on docker, only the localhost port is different. (In a production environment, most likely you going to run the databases on a different host). The main reason for active-active replication is high availability. If one of the nodes goes down, you still want your application to behave normally. You don’t want to hard-code your DSN on the application or keep checking the health of the database every time before you make a connection. Fair enough. [HAProxy] (<www.haproxy.org>), an open source project solves this particular change.