private synchronized void init() throws IOException {
    refresh(false);
    masterServices.getServerManager().registerListener(new ServerListener() {

      @Override
      public void serverAdded(ServerName serverName) {
        updateDefaultServers();
      }

      @Override
      public void serverRemoved(ServerName serverName) {
        updateDefaultServers();
      }
    });
  }
Table descriptor for <code>hbase:rsgroup</code> catalog table
hbase-server/src/main/java/org/apache/hadoop/hbase/rsgroup/RSGroupInfoManagerImpl.java