title: Wait Timeout setting of mysql and JDBC error
body: <p>I see the following error in the log:</p>
  
  <blockquote>
    <p>Caused by:
    com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException:
    No operations allowed after connection
    closed.Connection was implicitly
    closed by the driver.</p>
  </blockquote>
  
  <p>I have reduced the wait_timeout in my.cnf to 60
  Should I set the default value for this parameter?
  I am told my Java Programmers that this may be one of the reasons.</p>