logger.info("START: GenericClusterController.onMessage()");
if (changeContext == null || changeContext.getType() != Type.CALLBACK) {
_cache.requireFullRefresh();
}
ClusterEvent event = new ClusterEvent("messageChange");
event.addAttribute("helixmanager", changeContext.getManager());
event.addAttribute("instanceName", instanceName);
event.addAttribute("changeContext", changeContext);
event.addAttribute("eventData", messages);
_eventQueue.put(event);
if (_clusterStatusMonitor != null && messages != null) {
_clusterStatusMonitor.addMessageQueueSize(instanceName, messages.size());
}