On Mon, Oct 14, 2019, 11:42 PM Han Zhou <zhou...@gmail.com> wrote: > > > On Mon, Oct 14, 2019 at 8:20 AM <nusid...@redhat.com> wrote: > >> From: Numan Siddique <nusid...@redhat.com> >> >> The commit [1] force drops all connections when the db read/write status >> changes. >> Prior to the commit [1], when there was read/write status change, the >> existing >> jsonrpc sessions with 'db_change_aware' set to true, were not updated >> with the >> changed 'read_only' value. If the db status was changed to 'standby', the >> existing >> clients could still write to the db. >> >> In the case of pacemaker OVN HA, OVN OCF script 'start' action starts the >> ovsdb-servers in read-only state and later, it sets to read-write in the >> 'promote' action. We have observed that if some ovn-controllers connect to >> the SB ovsdb-server (in read-only state) just before the 'promote' action, >> the connection is not reset all the times and these ovn-controllers >> remain connected >> to the SB ovsdb-server in read-only state all the time. Even though >> the commit [1] calls 'ovsdb_jsonrpc_server_reconnect()' with 'forced' flag >> set to true when the db read/write status changes, somehow the FSM misses >> resetting >> the connections of these ovn-controllers. >> >> I think this needs to be addressed in the FSM. This patch doesn't address >> this FSM issue. Instead it changes the behavior of >> 'ovsdb_jsonrpc_server_set_read_only()' >> by setting the 'read_only' flag of all the jsonrpc sessions instead of >> forcefully >> resetting the connection. >> >> I think there is no need to reset the connection. In large scale >> production >> deployements with OVN, this results in unnecessary waste of CPU cycles as >> ovn-controllers >> will have to connect twice - once during 'start' action and again during >> 'promote'. >> >> [1] - 2a9679e3b2c6("ovsdb-server: drop all connections on read/write >> status change") >> >> Acked-by: Dumitru Ceara <dce...@redhat.com> >> Signed-off-by: Numan Siddique <nusid...@redhat.com> >> --- >> >> > Thanks Numan. Is this the root cause of the ovn-controller transaction > failure you mentioned at last OVN meeting? >
Hi Han, Yes. This is the root cause. Earlier I was suspecting ovn-controller though. Thanks Numan _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev