Re: [libvirt] [PATCH 0/9] Resolve libvirtd hang on termination with connected long running client

On 19.01.2018 20:23, John Ferlan wrote: > RFC: > https://www.redhat.com/archives/libvir-list/2018-January/msg00318.html > > Adjustments since RFC... > > Patches 1&2: No change, were already R-B'd > Patch 3: Removed code as noted in code review, update commit message > Patch 4: From old series removed, see below for more details > Patch 9: no change > NB: Patches 5-8 and 10 from Nikolay Shirokovskiy <nshirokovskiy(a)virtuozzo.com&gt; > are removed as they seemed to not be necessary > > Replaced the former patch 4 with series of patches to (slowly) provide > support to disable new connections, handle removing waiting jobs, causing > the waiting workers to quit, and allow any running jobs to complete. > > As it turns out, waiting for running jobs to complete cannot be done > from the virNetServerClose callbacks because that means the event loop > processing done during virNetServerRun will not allow any currently > long running worker job thread a means to complete. Hi, John. So you suggest a different appoarch. Instead of introducing means to help rpc threads to finish after event loop is finished (stateShutdown hook in my series) you suggest to block futher new rpc processing and then waiting running rpc calls to finish keeping event loop running for that purpose. This could lead to libvirtd never finish its termination if one of qemu processes do not respond for example. In case of long running operation such as migration finishing can take much time. On the over hand if we finish rpc threads abruptly as in case of stateShutdown hook we will deal with all possible error paths on daemon finishing. May be good approach is to abort long running operation, then give rpc threads some time to finish as you suggest and only after that finish them abruptly to handle hanging qemu etc.