Testing a write query on pgpool

The load-balancing mode in pgpool presumably distributes connections according to server weight. Then, master/slave mode defines which servers are read-only as opposed to writable.

But can we depend on this behavior? We should at least verify these claims before using such a configuration in a production environment. Our uptime depends upon it.

Getting ready

Make sure pgpool is installed and configured according to the Installing pgpool and Configuring pgpool for master/slave mode recipes. We will follow these two recipes by testing a pool setup with write activity, so we need a fully functional pgpool environment.

To simplify this recipe, perform all the tests as the postgres system user. To facilitate this, we may need to set all the pg_hba.conf authentication types to trust, though we strongly suggest user and password combinations instead.

If our primary PostgreSQL server is on 192.168.56.10, we can connect to pgpool by using port 9999. With psql, we can connect...