@Inject
  public static void init(Configuration configuration) {
    THREAD_POOL_CORE_SIZE = configuration.getPropertyProvidersThreadPoolCoreSize();
    THREAD_POOL_MAX_SIZE = configuration.getPropertyProvidersThreadPoolMaxSize();
    THREAD_POOL_WORKER_QUEUE_SIZE = configuration.getPropertyProvidersWorkerQueueSize();
    COMPLETION_SERVICE_POLL_TIMEOUT = configuration.getPropertyProvidersCompletionServiceTimeout();
    EXECUTOR_SERVICE = initExecutorService();
  }
Executor service is shared between all instances.
ambari-server/src/main/java/org/apache/ambari/server/controller/metrics/ThreadPoolEnabledPropertyProvider.java