Comment 1 for bug 1365373

This should be a defect from cinder.openstack.common.service.py, it should use eventlet's event instead of threading in service.py, here is the method to fix this in incubator(which is parent for nova and cinder component): https://github.com/openstack/oslo-incubator/commit/1e7007824374842bc8108dff5e5e2694e12932b2 . Note that the nova has merged the latest source while cinder doesn't, that's reason why causes the cinder-volume hang there all the time.
I will create a bug to cinder to track this issue, will update number later. This may take a long time to merged into community and ICM, so I'd like to provide a temp fix for this issue, which is using nova's service intead of cinders. Tested that periodically syc does work.