Can't establish a DB connection. (Maybe threads related)

Question

Hello,

I am getting this exception on the Rufus::Scheduler

ActiveRecord::ConnectionTimeoutError: could not obtain a database connection within 5 seconds. The max pool size is currently 30; consider increasing it.

I've increased the pool from 10 to 30. And I also monkey patched the method which raises the exception to also call ActiveRecord::Base.verify_active_connections! before doing its job.

And I also restarted the service which executes the script so that the new code is run.

Any ideas would be greatly appreciated.

Let me know if you need any other info about environment or whatnot.

Thank you.