Comment 3 for bug 1627220

The logs from the linked test run show it's a Xenial host using Ceph 10.2.2. There was a bug fix [1] that could result in heavily overloaded systems dropping update notifications which is fixed in v10.2.3. I'll submit a workaround patch for devstack-plugin-ceph that should avoid that issue regardless of the version used.

[1] http://tracker.ceph.com/issues/16404