Are there any limits on the size of an ActiveRecord connection pool?

We’re hitting some problems with concurrency, resulting in attempted connections to our db timing out. Taking into account our service workers and cron jobs, it looks like we need to increase the size of our Active Record connection pool to 20 - 25 up from the current default of 5.

Some platforms (Heroku), put limits on the size of the thread pool. Does anyone know of any limits, or other gotchas in this area for Aptible? We’re running puma/postgres on the Enclave platform.


Update: We increased the pool size from 5 to 25 on staging and there were no problems.

Hi @pschoeps! Indeed, Enclave doesn’t place limits on the size of the thread pool. If you continue to see issues related to database timeouts, please let us know here or by opening a support ticket at