title: ActiveMQ KahaDB compatibility
body: <p>We want to upgrade ActiveMQ 5.3 to 5.6 and also keep the connections information.
  Here is what we do, </p>
  
  <ol>
  <li>Backup files under <code>data\kahadb\</code> and uninstall AcitveMQ 5.3 </li>
  <li>Install ActiveMQ 5.6</li>
  <li>Overwrite the files under <code>data\kahadb</code> with previous backup files</li>
  </ol>
  
  <p>if the count of my clients is about 20, it works well.
  if the count of my clients is more than 100, i can't connect to my broker again.
  here are the logs in wrapper.log</p>
  
  <pre><code>Failed to load: class path resource [activemq.xml], reason: Error creating bean with name 'org.apache.activemq.xbean.XBeanBrokerService#0' defined in class path resource [activemq.xml]: Invocation of init method failed; nested exception is org.apache.kahadb.page.Transaction$InvalidPageIOException: Page id is not valid
  </code></pre>
  
  <p>we got some exception when we created a consumer:</p>
  
  <pre><code>Apache.NMS.ActiveMQ.BrokerException: java.io.EOFException : 
  Apache.NMS.ActiveMQ.Connection.SyncRequest(Command command, TimeSpan requestTimeout)
  Apache.NMS.ActiveMQ.Session.CreateConsumer(IDestination destination, String selector, Boolean noLocal)
  Apache.NMS.ActiveMQ.Session.CreateConsumer(IDestination destination)
  </code></pre>
  
  <p>Is the db compatible issue? or how to keep the connection data after upgrading MQ?</p>