JBoss EAP unavailable after Apache restarts when using mod_cluster

Solution Verified - Updated -


  • User needs to restart Apache (but JBoss is untouched)
  • Once Apache is started, JBoss is still not accessible for a short time (even though it's up)
  • After Apache is restarted, JBoss logs an error about a STATUS MCMP:

    ERROR [org.jboss.modcluster.mcmp.impl.DefaultMCMPHandler] (ContainerBackgroundProcessor[StandardEngine[jboss.web]]) Error [MEM: MEM: Can't read node: {4}] sending command STATUS to proxy, configuration will be reset

    And Apache logs a message like:

    [warn] manager_handler STATUS error: MEM: Can't read node
  • mod_cluster drops JBoss nodes when apache is reloaded

  • I am using apache with mod_cluster as a load balancer in front of a JBoss Cluster.When I issue apache a reload command, the JBoss nodes are unregistered and it takes approximately 10 seconds for the JBoss nodes to register again.This behaviour would be ok for an apache restart, but for a reload I was expecting no downtime. Is there any solution ?
  • httpd restart causes 503 for ~10s with mod_cluster.
  • mod_cluster not discovering nodes after restart of httpd.What could be the cause of this?


  • Red Hat JBoss Enterprise Application Platform (EAP) all versions
  • Apache or JBoss Enterprise Web Server (EWS) all versions (using mod_cluster)

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