ClientUpdateMessageImpl constructClientMessage(InternalCacheEvent event) {
    ClientUpdateMessageImpl clientMessage = null;
    EnumListenerEvent operation = event.getEventType();

    try {
      clientMessage = initializeMessage(operation, event);
    } catch (Exception e) {
      logger.fatal(String.format(
          "CacheClientNotifier: Cannot notify clients to perform operation %s on event %s",
          operation, event),
          e);
    }
    return clientMessage;
  }
The client represented by the proxyId is ready to receive updates.
geode-core/src/main/java/org/apache/geode/internal/cache/tier/sockets/CacheClientNotifier.java