protected final void internalStart(ZKWatcher zkWatcher) {
    if (AccessChecker.isAuthorizationSupported(getConfiguration())) {
      accessChecker = new AccessChecker(getConfiguration());
    } else {
      accessChecker = new NoopAccessChecker(getConfiguration());
    }
    zkPermissionWatcher =
      new ZKPermissionWatcher(zkWatcher, accessChecker.getAuthManager(), getConfiguration());
    try {
      zkPermissionWatcher.start();
    } catch (KeeperException e) {
      LOG.error("ZooKeeper permission watcher initialization failed", e);
    }
    rpcServer.start();
  }
Base class for Master and RegionServer RpcServices.
hbase-server/src/main/java/org/apache/hadoop/hbase/HBaseRpcServicesBase.java