private String getHostnameAndPort(Throwable error) {
    Matcher matcher = ADDR_MSG_MATCHER.matcher(error.getMessage());
    if (matcher.matches()) {
      return matcher.group(1);
    } else {
      return "";
    }
  }
{@link BufferedMutator} implementation based on {@link AsyncBufferedMutator}.
hbase-client/src/main/java/org/apache/hadoop/hbase/client/BufferedMutatorOverAsyncBufferedMutator.java