title: Frequent PG::ConnectionBad: connection is closed errors with RDS and rails / activerecord
body: <p>I'm seeing a large number of <code>PG::ConnectionBad: connection is closed</code>errors in a rails 4 application using unicorn. The DB pool is set to 10, the connect_timeout is 2, the reaping_frequency is 10, and reconnect is true.</p>
  
  <p>None of this seems to completely eliminate the problem. It is MUCH more frequent right after a deploy when the unicorn servers are restarted.</p>
  
  <p>There do not seem to be actual connection issues to the database - many many connections are working just fine.</p>
  
  <p>What could be causing this?</p>