Hi, mom-vdsm.service contains: Requires=vdsmd.service After=vdsmd.service

So when Shira restarted vdsm, mom was also restarted. [journalctl --unit vdsmd] Nov 08 18:25:27 RHEL7.2Server systemd[1]: Stopping Virtual Desktop Server Manager... Nov 08 18:25:27 RHEL7.2Server vdsmd_init_common.sh[3053]: vdsm: Running run_final_hooks Nov 08 18:25:27 RHEL7.2Server systemd[1]: Starting Virtual Desktop Server Manager... [journalctl --unit mom-vdsm] Nov 08 18:17:23 RHEL7.2Server systemd[1]: Starting MOM instance configured for VDSM purposes... Nov 08 18:25:16 RHEL7.2Server systemd[1]: Stopping MOM instance configured for VDSM purposes... Nov 08 18:25:29 RHEL7.2Server systemd[1]: Started MOM instance configured for VDSM purposes. But mom then immediately failed with: 2016-11-08 18:25:08,008 - mom.RPCServer - INFO - ping() 2016-11-08 18:25:08,010 - mom.RPCServer - INFO - getStatistics() 2016-11-08 18:25:17,028 - mom.RPCServer - INFO - RPC Server ending 2016-11-08 18:25:24,705 - mom.GuestManager - INFO - Guest Manager ending 2016-11-08 18:25:26,575 - mom.HostMonitor - INFO - Host Monitor ending 2016-11-08 18:25:29,869 - mom - INFO - MOM starting 2016-11-08 18:25:29,905 - mom.HostMonitor - INFO - Host Monitor starting 2016-11-08 18:25:29,905 - mom - INFO - hypervisor interface vdsmjsonrpcbulk 2016-11-08 18:25:30,029 - mom.vdsmInterface - ERROR - Cannot connect to VDSM! [Errno 111] Connection refused 2016-11-08 18:25:30,030 - mom - ERROR - Failed to initialize MOM threads Traceback (most recent call last): File "/usr/lib/python2.7/site-packages/mom/__init__.py", line 29, in run hypervisor_iface = self.get_hypervisor_interface() File "/usr/lib/python2.7/site-packages/mom/__init__.py", line 217, in get_hypervisor_interface return module.instance(self.config) File "/usr/lib/python2.7/site-packages/mom/HypervisorInterfaces/vdsmjsonrpcbulkInterface.py", line 47, in instance return JsonRpcVdsmBulkInterface() File "/usr/lib/python2.7/site-packages/mom/HypervisorInterfaces/vdsmjsonrpcbulkInterface.py", line 29, in __init__ super(JsonRpcVdsmBulkInterface, self).__init__() File "/usr/lib/python2.7/site-packages/mom/HypervisorInterfaces/vdsmjsonrpcInterface.py", line 43, in __init__ .orRaise(RuntimeError, 'No connection to VDSM.') File "/usr/lib/python2.7/site-packages/mom/optional.py", line 28, in orRaise raise exception(*args, **kwargs) RuntimeError: No connection to VDSM. The question here is, how much time does VDSM need to allow jsonrpc to connect and request a ping and list of VMs?