Generic connection pooling for Ruby. MongoDB has its own connection pool. ActiveRecord has its own connection pool. This is a generic connection pool that can be used with anything, e.g. Redis, Dalli and other Ruby network clients. **WARNING**: Don't ever use `Timeout.timeout` in your Ruby code or you will see occasional silent corruption and mysterious errors. The Timeout API is unsafe and cannot be used correctly, ever. Use proper socket timeout options as exposed by Net::HTTP, Redis, Dalli, etc.