Hi Numan, Yes , the DNS packets are sent by VMs . We have DNS records for these VMs so the controller is catching all DNS requests and failing to respond in a timely manner.
I think this relates to the fact that there is no incremental handler for SB DNS. In short the blocking thread causes us all sorts of problems . Hope that makes sense Gav On Fri, Oct 4, 2024 at 15:34 Numan Siddique <num...@ovn.org> wrote: > On Fri, Oct 4, 2024 at 5:50 PM Gavin McKee via discuss > <ovs-discuss@openvswitch.org> wrote: > > > > Hi, > > > > We currently experience DNS related timeouts when the ovn controller > > is under high load. > > > > Will this commit ensure that DNS packets needing to be forwarded to an > > external resolver will be processed in a timely manner and not lead to > > timeouts? > > > https://github.com/ovn-org/ovn/commit/762ae66cd70efa149d91d35305fcef0040e9addd > > > > This particular patch is useful when the ovn-controller calls > dns_resolve() of ovs/lib/dns_resolve.c [1] > to resolve a dns entry. > > In your case, what are these DNS packets? Are these sent by VMs and > ovn-controller pinctrl thread handles > these requests and its blocking due to pinctrl_mutex ? > > If so, I think we need to find a solution for this problem, but the > above commit will definitely not help you. > Maybe we can maintain a separate mutex to protect the dns_cache [2] so > that even if ovn-controller main thread > is busy (and not updating the internal dns cache), the DNS packets > from the VMs can be handled without any delay > in the pinctrl thread. > > [1] - https://github.com/openvswitch/ovs/blob/main/lib/dns-resolve.c#L148 > [2] - https://github.com/ovn-org/ovn/blob/main/controller/pinctrl.c#L3288 > > > Thanks > Numan > > > We currently run OVN 23.09.04. > > > > Thanks > > > > Gav > > _______________________________________________ > > discuss mailing list > > disc...@openvswitch.org > > https://mail.openvswitch.org/mailman/listinfo/ovs-discuss > > >
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