code: void setErrorStatus(String msg, Exception e) {
      this.e = new IOException(msg + " " + (e == null ? "" : e.toString()));
      
      // no more writes will be accepted
      this.isDisabled = true;
      
      // close the executor
      sendExecutor.shutdown();
      LOG.error(msg, e);
    }
docs: If any operation for this channel fail, the error status is set. Parent
  output stream, based on this information, decides whether the upload can be
  still continued with remaining channels.