static boolean isFatalConnectionException(ExceptionResponse e) {
    if (e.getExceptionClassName().equals(FatalConnectionException.class.getName())) {
      return true;
    }
    // try our best to check for sub classes of FatalConnectionException
    try {
      return e.getExceptionClassName() != null && FatalConnectionException.class.isAssignableFrom(
        Class.forName(e.getExceptionClassName(), false, IPCUtil.class.getClassLoader()));
      // Class.forName may throw ExceptionInInitializerError so we have to catch Throwable here
    } catch (Throwable t) {
      LOG.debug("Can not get class object for {}", e.getExceptionClassName(), t);
      return false;
    }
  }
Returns True if the exception is a fatal connection exception.
hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/IPCUtil.java