Connection Pooling in typeorm with postgressql

Question

I've gone through enough articles and typeorm official documentation on setting up connection pooling with typeorm and postgressql but couldn't find a solution.

All the articles, I've seen so far explains about adding the max/Poolsize attribute in orm configuration or connection pooling but this is not setting up a pool of idle connections in the database.

When I verify pg_stat_activity table after the application bootstraps, I could not see any idle connections in the DB but when a request is sent to the application I could see an active connection to the DB

The max/poolSize attribute defined under the extras in the orm configuration merely acts as the max number of connections that can be opened from the application to the db concurrently.

What I'm expecting is that during the bootstrap, the application opens a predefined number of connections with the database and keep it in idle state. When a request comes into the application one of the idle connection is picked up and the request is served.

Can anyone provide your insights on how to have this configuration defined with typeorm and postgresql?

Answer 1

TypeORM uses node-postgres which has built in pg-pool and doesn't have that kind of option, as far as I can tell. It supports a max, and as your app needs more connections it will create them, so if you want to pre-warm it, or maybe load/stress test it, and see those additional connections you'll need to write some code that kicks off a bunch of async queries/inserts.

I think I understand what you're looking for as I used to do enterprise Java, and connection pools in things like glassfish and jboss have more options where you can keep hot unused connections in the pool. There are no such options in TypeORM/node-postgres though.