Rails connection pool size optimizations

[jeremylenz]

@Shimon_Shtein

From looking into the Katello code, I have seen candlepin event listener that uses Stomp gem underneath, and that gem spawns a new thread for its listener. In our case the listener will do database queries along the way. Additionally there is a Katello event polling thread that also uses database queries.

I wonder if moving forward with Saying goodbye to the Katello Event Daemon would also help with this?

cc @Jonathon_Turel