On Tue, Nov 8, 2016 at 8:51 PM, Martin Perina <mperina(a)redhat.com&gt; wrote: > > Adding Piotr > > On Tue, Nov 8, 2016 at 5:52 PM, Martin Sivak <msivak(a)redhat.com&gt; wrote: >> >> 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? >> It depends on recovery logic in vdsm and it can take quite some time.

On 9 Nov 2016, at 08:55, Francesco Romani <fromani(a)redhat.com&gt; wrote: ----- Original Message ----- > From: "Piotr Kliczewski" <pkliczew(a)redhat.com&gt; > To: "Martin Perina" <mperina(a)redhat.com&gt; > Cc: "Francesco Romani" <fromani(a)redhat.com&gt;, "Shira Maximov" <mshira(a)redhat.com&gt;, "devel" <devel(a)ovirt.org&gt; > Sent: Tuesday, November 8, 2016 9:31:43 PM > Subject: Re: [vdsm] Connection refused when talking to jsonrpc >>> 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/v >>> dsmjsonrpcbulkInterface.py", >>> line 47, in instance >>> return JsonRpcVdsmBulkInterface() >>> File "/usr/lib/python2.7/site-packages/mom/HypervisorInterfaces/v >>> dsmjsonrpcbulkInterface.py", >>> line 29, in __init__ >>> super(JsonRpcVdsmBulkInterface, self).__init__() >>> File "/usr/lib/python2.7/site-packages/mom/HypervisorInterfaces/v >>> dsmjsonrpcInterface.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? >>> >>> > It depends on recovery logic in vdsm and it can take quite some time. > > Please share vdsm logs so I could take a look? +1 the most likely cause is the recovery still in progress, however I was expecting a different error, so worth looking at the logs.

Bests, -- Francesco Romani Red Hat Engineering Virtualization R & D Phone: 8261328 IRC: fromani _______________________________________________ Devel mailing list Devel(a)ovirt.org http://lists.ovirt.org/mailman/listinfo/devel

> Isn’t the most likely cause by far a simple startup delay? We do open the listener “soon” and responds with code 99, but it’s still not instant of course That is possible of course and we handle those "errors" just fine. But connection refused never happened with xmlrpc. It might have been luck, but it always worked there :)

Martin On Wed, Nov 9, 2016 at 9:11 AM, Michal Skrivanek <michal.skrivanek(a)redhat.com&gt; wrote: > >> On 9 Nov 2016, at 08:55, Francesco Romani <fromani(a)redhat.com&gt; wrote: >> >> ----- Original Message ----- >>> From: "Piotr Kliczewski" <pkliczew(a)redhat.com&gt; >>> To: "Martin Perina" <mperina(a)redhat.com&gt; >>> Cc: "Francesco Romani" <fromani(a)redhat.com&gt;, "Shira Maximov" < mshira(a)redhat.com&gt;, "devel" <devel(a)ovirt.org&gt; >>> Sent: Tuesday, November 8, 2016 9:31:43 PM >>> Subject: Re: [vdsm] Connection refused when talking to jsonrpc >> >> >>>>> 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/v >>>>> dsmjsonrpcbulkInterface.py", >>>>> line 47, in instance >>>>> return JsonRpcVdsmBulkInterface() >>>>> File "/usr/lib/python2.7/site-packages/mom/HypervisorInterfaces/v >>>>> dsmjsonrpcbulkInterface.py", >>>>> line 29, in __init__ >>>>> super(JsonRpcVdsmBulkInterface, self).__init__() >>>>> File "/usr/lib/python2.7/site-packages/mom/HypervisorInterfaces/v >>>>> dsmjsonrpcInterface.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? >>>>> >>>>> >>> It depends on recovery logic in vdsm and it can take quite some time. >>> >>> Please share vdsm logs so I could take a look? >> >> +1 >> >> the most likely cause is the recovery still in progress, however I was expecting >> a different error, so worth looking at the logs. > > Isn’t the most likely cause by far a simple startup delay? We do open the listener “soon” and responds with code 99, but it’s still not instant of course > >> >> Bests, >> >> -- >> Francesco Romani >> Red Hat Engineering Virtualization R & D >> Phone: 8261328 >> IRC: fromani >> _______________________________________________ >> Devel mailing list >> Devel(a)ovirt.org >> http://lists.ovirt.org/mailman/listinfo/devel >> >> >

On 9 Nov 2016, at 09:57, Francesco Romani <fromani(a)redhat.com&gt; wrote: ----- Original Message ----- > From: "Piotr Kliczewski" <pkliczew(a)redhat.com&gt; > To: "Martin Sivak" <msivak(a)redhat.com&gt; > Cc: "Michal Skrivanek" <michal.skrivanek(a)redhat.com&gt;, "Francesco Romani" <fromani(a)redhat.com&gt;, "Shira Maximov" > <mshira(a)redhat.com&gt;, "devel" <devel(a)ovirt.org&gt; > Sent: Wednesday, November 9, 2016 9:54:02 AM > Subject: Re: [ovirt-devel] [vdsm] Connection refused when talking to jsonrpc > > On Wed, Nov 9, 2016 at 9:48 AM, Martin Sivak <msivak(a)redhat.com&gt; wrote: > >>> Isn’t the most likely cause by far a simple startup delay? We do open >> the listener “soon” and responds with code 99, but it’s still not instant >> of course >> >> That is possible of course and we handle those "errors" just fine. But >> connection refused never happened with xmlrpc. It might have been >> luck, but it always worked there :) >> >> > There is no difference how we open listening socket (it is used by both > protocols) and I have seen the engine attempting to connect using both > protocols > before the socket was open. What is the time difference that you see? Not sure I reproduced correctly, but it seems a race on startup. I got the same error on my box, and here it happens if mom tries to connect to the unix socket /var/run/vdsm/mom-vdsm.sock *before* that Vdsm creates it. Once vdsmd succesfully starts, a restart of mom-vdsm seems to fix all the issues. I'm not sure yet if that's all of it and how to handle with systemd dependencies. Perhaps Nir's suggestion past in the thread to notify systemd is a good first step in the right direction.

HTH, -- Francesco Romani Red Hat Engineering Virtualization R & D Phone: 8261328 IRC: fromani