On 04/24/2018 08:05 AM, Han Zhou wrote: > On Mon, Apr 23, 2018 at 12:21 AM, Wei Li <[email protected]> wrote: >> Hi Han, >> >> >> On 04/19/2018 06:07 AM, Han Zhou wrote: >>> On Wed, Apr 18, 2018 at 1:41 PM, Mike Spreitzer <[email protected]> > wrote: >>>> How big a system can OVN manage? I am told some local experimenters > did >>>> some tests about two years ago, and ran into CPU saturation at the > south >>>> DB at around a hundred hypervisors. >>>> >>>> Thanks, >>>> Mike >>>> >>> In our testing env (setup with > https://github.com/openvswitch/ovn-scale-test), >>> with 1k hypervisors the central node CPU (including NB DB, SB DB and >>> ovn-northd) is still low. >> We observed a high cpu utilization in our environment(about 15 HVs) when > doing >> a high rate of port insertion/deletion. It seems ovn-northd recompute > everything on >> NB change, do you have any optimization suggestion on this scenario? >> > What's the rate of port insertion/deletion in your testing? Since northd > processed NB DB data only, the number of HVs actually doesn't matter. In > our testing the rate was around 1 port/sec, so it was not that hot. > It might trigger hot CPU on northd if NB DB changes very frequently, but it > doesn't mean there is real problem. northd doesn't react to each change, > but instead it computes against the latest data in NB DB. So what matters > is the size of total data in NB DB, and how long it takes for northd to > finish a round of computing for this size of data. We do a 10 to 100 ports insertion per second(in a batch style) when doing stress test, but as you explained, I think it's not a big problem now :)
> >>> CPU is rather busy on HVs, but there is an ongoing optimization with > very >>> promising test result: >>> https://mail.openvswitch.org/pipermail/ovs-dev/2018-April/346136.html >> Is there will be a similar incremental processing for ovn-northd in your > roadmap? > Incremental processing for northd has been discussed in this community and > I think it is in the roadmap :) According to previous discussions, the > approach for northd incremental processing will be different from what I am > doing in ovn-controller though. Unlike ovn-controller, the input of northd > is purely NB DB, so the proposal was to rewrite northd with some domain > specific language (a datalog approach) so that the incremental processing > happens in a more clean way. But I am not sure about the progress of this > work. Ben may have more information. Sounds great, looking forward to this :D Thanks, Wei > >> Thanks, >> Wei >> >>> Thanks, >>> Han >>> >>> >>> >>> _______________________________________________ >>> discuss mailing list >>> [email protected] >>> https://mail.openvswitch.org/mailman/listinfo/ovs-discuss _______________________________________________ discuss mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-discuss
