@Override
public boolean process(String type, String message, Object object) {
Applications applications = (Applications) object;
if (GroupInstanceTerminatingEvent.class.getName().equals(type)) {
// Return if applications has not been initialized
if (!applications.isInitialized()) return false;
// Parse complete message and build event
GroupInstanceTerminatingEvent event =
(GroupInstanceTerminatingEvent)
MessagingUtil.jsonToObject(message, GroupInstanceTerminatingEvent.class);
ApplicationsUpdater.acquireWriteLockForApplication(event.getAppId());
try {
return doProcess(event, applications);
} finally {
ApplicationsUpdater.releaseWriteLockForApplication(event.getAppId());
}
} else {
if (nextProcessor != null) {
// ask the next processor to take care of the message.
return nextProcessor.process(type, message, applications);
} else {
throw new RuntimeException(
String.format(
"Failed to process message using available message processors: [type] %s [body] %s",
type, message));
}
}
}
private boolean doProcess(GroupInstanceTerminatingEvent event, Applications applications) {
// Validate event against the existing applications
Application application = applications.getApplication(event.getAppId());
if (application == null) {
if (log.isWarnEnabled()) {
log.warn(String.format("Application does not exist: [service] %s", event.getAppId()));
}
return false;
}
Group group = application.getGroupRecursively(event.getGroupId());
if (group == null) {
if (log.isWarnEnabled()) {
log.warn(
String.format(
"Group not exists in service: [AppId] %s [groupId] %s",
event.getAppId(), event.getGroupId()));
return false;
}
} else {
// Apply changes to the applications
GroupInstance context = group.getInstanceContexts(event.getInstanceId());
if (context == null) {
if (log.isWarnEnabled()) {
log.warn(
String.format(
"Group Instance not exists in Group: [AppId] %s [groupId] %s "
+ "[instanceId] %s",
event.getAppId(), event.getGroupId(), event.getInstanceId()));
return false;
}
}
// Apply changes to the topology
GroupStatus status = GroupStatus.Terminating;
if (!context.isStateTransitionValid(status)) {
log.error("Invalid State Transition from " + context.getStatus() + " to " + status);
return false;
}
context.setStatus(status);
}
// Notify event listeners
notifyEventListeners(event);
return true;
}