title: AWS RDS PostgreSQL error "remaining connection slots are reserved for non-replication superuser connections"
body: <p>In the dashboard I see there are currently 22 open connections to the DB instance, blocking new connections with the error: </p>
  
  <blockquote>
    <p>remaining connection slots are reserved for non-replication superuser connections.</p>
  </blockquote>
  
  <p>I'm accessing the DB from web service API running on EC2 instance and always keep the best practise of:</p>
  
  <pre><code>Connection connection = DriverManager.getConnection(URL, USER_NAME, PASSWORD);
  Class.forName(DB_CLASS);
  Statement statement = connection.createStatement();
  ResultSet resultSet = statement.executeQuery(SQL_Query_String);
  ...
  resultSet.close();
  statement.close();
  connection.close();
  </code></pre>
  
  <ol>
  <li><p>Can I do something else in the code?</p></li>
  <li><p>Should I do something else in the DB management?</p></li>
  <li><p>Is there a way to periodically close connections?</p></li>
  </ol>