static EventLogger getInstance(HiveConf conf) {
      if (instance == null) {
        synchronized (EventLogger.class) {
          if (instance == null) {
            instance = new EventLogger(conf, SystemClock.getInstance());
            ShutdownHookManager.addShutdownHook(instance::shutdown);
          }
        }
      }
      return instance;
    }
Log events from hive hook using protobuf serialized format, partitioned by date.
ql/src/java/org/apache/hadoop/hive/ql/hooks/HiveProtoLoggingHook.java