@Override
  public ServerName getServerHoldingRegion(TableName tn, byte[] regionName) throws IOException {
    byte[] startKey = RegionInfo.getStartKey(regionName);
    HRegionLocation regionLoc = null;
    try (RegionLocator locator = connection.getRegionLocator(tn)) {
      regionLoc = locator.getRegionLocation(startKey, true);
    }
    if (regionLoc == null) {
      LOG.warn("Cannot find region server holding region {}", Bytes.toStringBinary(regionName));
      return null;
    }
    return regionLoc.getServerName();
  }
Returns a ClusterStatus for this HBase cluster
hbase-it/src/test/java/org/apache/hadoop/hbase/DistributedHBaseCluster.java