Ceph » mgr

From list thread: "[ceph-users] ZeroDivisionError: float division by zero in /usr/lib/ceph/mgr/dashboard/module.py (12.2.4)"

ceph-mgr[1324]: [15/Apr/2018:09:47:12] HTTP Traceback (most recent call last):
ceph-mgr[1324]:   File "/usr/lib/python2.7/dist-packages/cherrypy/_cprequest.py", line 670, in respond
ceph-mgr[1324]:     response.body = self.handler()
ceph-mgr[1324]:   File "/usr/lib/python2.7/dist-packages/cherrypy/lib/encoding.py", line 217, in __call__
ceph-mgr[1324]:     self.body = self.oldhandler(*args, **kwargs)
ceph-mgr[1324]:   File "/usr/lib/python2.7/dist-packages/cherrypy/lib/jsontools.py", line 63, in json_handler
ceph-mgr[1324]:     value = cherrypy.serving.request._json_inner_handler(*args, **kwargs)
ceph-mgr[1324]:   File "/usr/lib/python2.7/dist-packages/cherrypy/_cpdispatch.py", line 61, in __call__
ceph-mgr[1324]:     return self.callable(*self.args, **self.kwargs)
ceph-mgr[1324]:   File "/usr/lib/ceph/mgr/dashboard/module.py", line 991, in list_data
ceph-mgr[1324]:     return self._osds_by_server()
ceph-mgr[1324]:   File "/usr/lib/ceph/mgr/dashboard/module.py", line 1040, in _osds_by_server
ceph-mgr[1324]:     osd_map.osds_by_id[osd_id])
ceph-mgr[1324]:   File "/usr/lib/ceph/mgr/dashboard/module.py", line 1007, in _osd_summary
ceph-mgr[1324]:     result['stats'][s.split(".")[1]] = global_instance().get_rate('osd', osd_spec, s)
ceph-mgr[1324]:   File "/usr/lib/ceph/mgr/dashboard/module.py", line 268, in get_rate
ceph-mgr[1324]:     return (data[-1][1] - data[-2][1]) / float(data[-1][0] - data[-2][0])
ceph-mgr[1324]: ZeroDivisionError: float division by zero

I'm opening this as a ceph-mgr bug rather than in a specific module, because it strikes me as odd that we had two datapoints with the same timestamp (hence zero delta and the exception) to begin with.

I wonder if there is something happening during a failure that's getting a too-quick resend of stats when sessions bounce or similar?