Currently, we have two Postgres server with master-slave streaming replication. All application servers are directly pointing to master server only. I am planning to setup new server for PgPool, at the time of divert app server to PgPool, I will pool out application server one by one from Load balancer and point it to PgPool which will not affect our application.
That should probably minimize your downtime. Still you need to change the port number (from database port to pgpool port) in the App configuration, will that not require the Application restart ? I am just curious to know.
Could you pls send me steps how to install PgPool without PgPoolAdmin?
Below link has complete instructions to install and configure pgPool