It would be a good idea to get some more robust logging into Rails 4.1. Rails has grown up, and so have many of the applications using it. Rails logging starts to brake down when you need to track down the specific server and PID that is associated with an error. If you use a log aggregator, without information on PID and server, log messages interleave, and become hard to visually associate when you have 100 rails processes distributed across 10 servers.