Ceph » CephFS

http://qa-proxy.ceph.com/teuthology/teuthology-2017-05-30_05:10:01-fs-kraken---basic-smithi/1243987/teuthology.log

        # Check that we got up to a respectable rate during the purge.  This is totally
        # racy, but should be safeish unless the cluster is pathologically slow, or
        # insanely fast such that the deletions all pass before we have polled the
        # statistics.
        if throttle_type == self.OPS_THROTTLE:
            if ops_high_water < mds_max_purge_ops / 2:
                raise RuntimeError("Ops in flight high water is unexpectedly low ({0} / {1})".format(
                    ops_high_water, mds_max_purge_ops
                ))
        elif throttle_type == self.FILES_THROTTLE:
            if files_high_water < mds_max_purge_files / 2:
                raise RuntimeError("Files in flight high water is unexpectedly low ({0} / {1})".format(
                    ops_high_water, mds_max_purge_files
                ))

the ops_high_water check failed. The check is too racy. the timing of evaluating delayed strays and receiving cap releases affect the check.