title: Session 0x0 for server null, unexpected error, closing socket connection and attempting reconnect
body: <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-html lang-html prettyprint-override"><code>WARN  [org.apache.zookeeper.ClientCnxn] - Session 0x0 for server null, unexpected error, closing socket connection and attempting reconnect
  java.net.ConnectException: Connection timed out: no further information
   at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
   at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:744)
   at org.apache.zookeeper.ClientCnxnSocketNIO.doTransport(ClientCnxnSocketNIO.java:361)
   at org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:1081)</code></pre>
  </div>
  </div>
  </p>
  
  <p>The mistake was repeated all the time.</p>