protected Collection<ServerName> fetchPeerAddresses() {
    try {
      return FutureUtils.get(connect().getAdmin().getRegionServers(true));
    } catch (IOException e) {
      LOG.debug("Fetch peer addresses failed", e);
      return Collections.emptyList();
    }
  }
Get the list of all the region servers from the specified peer
@return list of region server addresses or an empty list if the slave is unavailable
hbase-server/src/main/java/org/apache/hadoop/hbase/replication/HBaseReplicationEndpoint.java