[barryhennessy]

Any chance I could convince you to share some of those 'rare exceptions'? I love a good exception ;)

Also they're where the real insights are.

[jmstfv]

Lately, Rails has been complaining about connection timeouts, stating that all connections in the pool were in use (this usually happens when Sidekiq, a background jobs framework, processes multiple long-running jobs).

By default, the connection pool in Rails contains 5 connections, and they time out within 5 seconds.