title: Connection Pool for rails 5
body: <p>I am having this issue with rails 5 rc1. Does anyone have any idea how to configure it in the environment files and what is the default connection pool size for rails 5 active record.</p>
  
  <pre><code>   Puma caught this error: could not obtain a connection from the pool within 5.000 seconds (waited 5.000 seconds); all pooled connections were in use (ActiveRecord::ConnectionTimeoutError)
      /home/bsethi/.rvm/gems/ruby-2.2.2/gems/activerecord-5.0.0.rc1/lib/active_record/connection_adapters/abstract/connection_pool.rb:202:in `block in wait_poll'
      /home/bsethi/.rvm/gems/ruby-2.2.2/gems/activerecord-5.0.0.rc1/lib/active_record/connection_adapters/abstract/connection_pool.rb:193:in `loop'
      /home/bsethi/.rvm/gems/ruby-2.2.2/gems/activerecord-5.0.0.rc1/lib/active_record/connection_adapters/abstract/connection_pool.rb:193:in `wait_poll'
      /home/bsethi/.rvm/gems/ruby-2.2.2/gems/activerecord-5.0.0.rc1/lib/active_record/connection_adapters/abstract/connection_pool.rb:154:in `internal_poll'
      /home/bsethi/.rvm/gems/ruby-2.2.2/gems/activerecord-5.0.0.rc1/lib/active_record/connection_adapters/abstract/connection_pool.rb:278:in `internal_poll'
      /home/bsethi/.rvm/gems/ruby-2.2.2/gems/activerecord-5.0.0.rc1/lib/active_record/connection_adapters/abstract/connection_pool.rb:148:in `block in poll'
  </code></pre>