Is there any difference to restore DB on existing cluster vs. fresh cluster, in terms of performance?
If I don't have to restore on fresh cluster, which is recommended? For now, since ovn-northd always recomputes the whole DB, I guess not much difference? With incremental-process, would restoring to a fresh cluster be better? Is it necessary to stop or restart ovn-northd during DB restore? Thanks! Tony > -----Original Message----- > From: Han Zhou <hz...@ovn.org> > Sent: Tuesday, August 4, 2020 11:13 AM > To: Tony Liu <tonyliu0...@hotmail.com> > Cc: ovs-discuss <ovs-discuss@openvswitch.org>; ovs-dev <ovs- > d...@openvswitch.org> > Subject: Re: [ovs-dev] [OVN] stale data complained by ovn-controller > after db restore > > > > On Tue, Aug 4, 2020 at 10:30 AM Tony Liu <tonyliu0...@hotmail.com > <mailto:tonyliu0...@hotmail.com> > wrote: > > > Hi, > > Here is how I restore OVN DB. > * Stop all ovn-nb-db, ovn-sb-db and ovn-northd services. > * Clean up all DB files. > * Start all DB services. Fresh ovn-nb-db and ovn-sb-db clusters are > up and > running. > * Set DB election timer to 10s. > * Restore DB to ovn-nb-db by ovsdb-client. > * Start all ovn-northd services. > > A few minutes after, ovn-sb-db is fully synced with ovn-nb-db. > > Now, the client of ovn-sb-db, ovn-controller and nova-compute > complaint about > "stale data". The chassis node is not getting updated. > ======== > 2020-08-04 09:07:45.892 26 INFO ovsdbapp.backend.ovs_idl.vlog [-] > tcp:10.6.20.84:6642 <http://10.6.20.84:6642> : connected > 2020-08-04 09:07:45.895 26 WARNING ovsdbapp.backend.ovs_idl.vlog [-] > tcp:10.6.20.84:6642 <http://10.6.20.84:6642> : clustered database server > has stale data; trying another server > ======== > > Restarting ovn-controller and nova-compute resolve the issue. > > Is this expected? As part of the DB restore process, should I > restart > ovn-controller and nova-compute on all chassis node? > > > > > Yes, this is expected if you freshly start a new cluster. (It wouldn't > happen if you simply restore the old data on the existing cluster. > However, I understand that the scenario of restoring data on a freshly > created cluster is a valid use case). > For this case, you could either restart ovn-controller, or trigger a > client side raft index reset by: > ovn-appctl -t ovn-controller sb-cluster-state-reset > > Similarly for ovn-northd: > ovn-appctl -t ovn-northd nb-cluster-state-reset > ovn-appctl -t ovn-northd sb-cluster-state-reset > > To use this command, you will need at least 20.06 of OVN and OVS master. > > > Thanks, > Han > > > > > Thanks! > > Tony > > _______________________________________________ > dev mailing list > d...@openvswitch.org <mailto:d...@openvswitch.org> > https://mail.openvswitch.org/mailman/listinfo/ovs-dev > _______________________________________________ discuss mailing list disc...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-discuss
