mongodump.error

2018-05-09T14:11:48.960+0800    local.oplog.rs  97447
2018-05-09T14:11:48.960+0800    done dumping local.oplog.rs (97447 documents)
2018-05-09T14:11:54.481+0800    Failed: error connecting to db server: no reachable servers
Traceback (most recent call last):
  File "mongodump_scroll.py", line 77, in <module>
    dump_queue()
  File "mongodump_scroll.py", line 61, in dump_queue
    mongodump(dump_item)
  File "mongodump_scroll.py", line 53, in mongodump
    subprocess.check_output(['sh', file_name])
  File "/home/master/.pyenv/versions/3.6.0/lib/python3.6/subprocess.py", line 336, in check_output
    **kwargs).stdout
  File "/home/master/.pyenv/versions/3.6.0/lib/python3.6/subprocess.py", line 418, in run
    output=stdout, stderr=stderr)
subprocess.CalledProcessError: Command '['sh', 'dump_with_range1525844707_19.sh']' returned non-zero exit status 1.