I can also run this command "sudo docker exec -it gnocchi_metricd gnocchi-upgrade" to do database migration to solve this issue. Here is my execution log.

2018-07-18 20:34:12,882 [23054] ERROR    cotyledon._utils: Unhandled exception
Traceback (most recent call last):
  File "/var/lib/kolla/venv/local/lib/python2.7/site-packages/cotyledon/_utils.py", line 95, in exit_on_exception
    yield
  File "/var/lib/kolla/venv/local/lib/python2.7/site-packages/cotyledon/_service.py", line 139, in _run
    self.run()
  File "/var/lib/kolla/venv/local/lib/python2.7/site-packages/gnocchi/cli/metricd.py", line 76, in run
    self._configure()
  File "/var/lib/kolla/venv/local/lib/python2.7/site-packages/tenacity/__init__.py", line 214, in wrapped_f
    return self.call(f, *args, **kw)
  File "/var/lib/kolla/venv/local/lib/python2.7/site-packages/tenacity/__init__.py", line 295, in call
    start_time=start_time)
  File "/var/lib/kolla/venv/local/lib/python2.7/site-packages/tenacity/__init__.py", line 252, in iter
    return fut.result()
  File "/var/lib/kolla/venv/local/lib/python2.7/site-packages/concurrent/futures/_base.py", line 455, in result
    return self.__get_result()
  File "/var/lib/kolla/venv/local/lib/python2.7/site-packages/tenacity/__init__.py", line 298, in call
    result = fn(*args, **kwargs)
  File "/var/lib/kolla/venv/local/lib/python2.7/site-packages/gnocchi/cli/metricd.py", line 161, in _configure
    six.moves.range(self.incoming.NUM_SACKS))
  File "/var/lib/kolla/venv/local/lib/python2.7/site-packages/gnocchi/incoming/__init__.py", line 56, in NUM_SACKS
    raise SackDetectionError(e)
SackDetectionError: int() argument must be a string or a number, not 'NoneType'
2018-07-18 20:34:12,996 [23074] INFO     gnocchi.common.ceph: Ceph storage backend use 'cradox' python library
2018-07-18 20:34:13,823 [23074] INFO     gnocchi.cli.metricd: Joined coordination group: gnocchi-processing
2018-07-18 20:34:18,019 [23107] INFO     gnocchi.common.ceph: Ceph storage backend use 'cradox' python library
2018-07-18 20:34:18,020 [23106] INFO     gnocchi.common.ceph: Ceph storage backend use 'cradox' python library
2018-07-18 20:34:18,025 [23108] INFO     gnocchi.common.ceph: Ceph storage backend use 'cradox' python library
2018-07-18 20:34:18,031 [23110] INFO     gnocchi.common.ceph: Ceph storage backend use 'cradox' python library
2018-07-18 20:34:18,845 [23074] DEBUG    gnocchi.cli.metricd: 0 metrics processed from 128 sacks
2018-07-18 20:34:18,846 [23074] DEBUG    gnocchi.cli.metricd: Full scan of sacks has been done
2018-07-18 20:34:19,320 [23108] INFO     gnocchi.cli.metricd: Joined coordination group: gnocchi-processing
2018-07-18 20:34:19,323 [23110] INFO     gnocchi.cli.metricd: Joined coordination group: gnocchi-processing
2018-07-18 20:34:19,355 [23106] INFO     gnocchi.cli.metricd: Joined coordination group: gnocchi-processing
2018-07-18 20:34:19,361 [23107] INFO     gnocchi.cli.metricd: Joined coordination group: gnocchi-processing
2018-07-18 20:34:19,731 [23108] DEBUG    gnocchi.cli.metricd: 0 metrics processed from 39 sacks
2018-07-18 20:34:19,732 [23108] DEBUG    gnocchi.cli.metricd: Full scan of sacks has been done
2018-07-18 20:34:20,629 [23110] DEBUG    gnocchi.cli.metricd: 0 metrics processed from 37 sacks
2018-07-18 20:34:20,629 [23110] DEBUG    gnocchi.cli.metricd: Full scan of sacks has been done
2018-07-18 20:34:21,787 [23107] DEBUG    gnocchi.cli.metricd: 0 metrics processed from 48 sacks
2018-07-18 20:34:21,787 [23107] DEBUG    gnocchi.cli.metricd: Full scan of sacks has been done
2018-07-18 20:34:22,763 [23106] DEBUG    gnocchi.cli.metricd: 0 metrics processed from 42 sacks
2018-07-18 20:34:22,763 [23106] DEBUG    gnocchi.cli.metricd: Full scan of sacks has been done