@BeforeClass
  public static void setUpBeforeClass() throws Exception {
    Configuration conf = UTIL.getConfiguration();
    conf.setLong(BootstrapNodeManager.REQUEST_MASTER_INTERVAL_SECS, 5);
    conf.setLong(BootstrapNodeManager.REQUEST_MASTER_MIN_INTERVAL_SECS, 1);
    conf.setLong(BootstrapNodeManager.REQUEST_REGIONSERVER_INTERVAL_SECS, 1);
    conf.setInt(HBaseRpcServicesBase.CLIENT_BOOTSTRAP_NODE_LIMIT, 2);
    conf.setLong(RpcConnectionRegistry.INITIAL_REFRESH_DELAY_SECS, 5);
    conf.setLong(RpcConnectionRegistry.PERIODIC_REFRESH_INTERVAL_SECS, 1);
    conf.setLong(RpcConnectionRegistry.MIN_SECS_BETWEEN_REFRESHES, 1);
    UTIL.startMiniCluster(3);
    REGISTRY = new RpcConnectionRegistry(conf, UserProvider.instantiate(conf).getCurrent());
  }
Make sure that we can update the bootstrap server from master to region server, and region server
could also contact each other to update the bootstrap nodes.
hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestBootstrapNodeUpdate.java