@Override
                public void operationComplete(Future<Channel> future) throws Exception {
                  if (future.isSuccess()) {
                    safeClose(future.getNow());
                  }
                }
Exception other than RemoteException thrown when calling create on namenode
hbase-asyncfs/src/main/java/org/apache/hadoop/hbase/io/asyncfs/FanOutOneBlockAsyncDFSOutputHelper.java