On Fri, Dec 27, 2013 at 11:09:02AM +0100, Salvatore Orlando <sorla...@nicira.com> wrote:
> Hi, > > We now have several patches under review which improve a lot how neutron > handles parallel testing. > In a nutshell, these patches try to ensure the ovs agent processes new, > removed, and updated interfaces as soon as possible, > > These patches are: > https://review.openstack.org/#/c/61105/ > https://review.openstack.org/#/c/61964/ > https://review.openstack.org/#/c/63100/ > https://review.openstack.org/#/c/63558/ > > There is still room for improvement. For instance the calls from the agent > into the plugins might be consistently reduced. > However, even if the above patches shrink a lot the time required for > processing a device, we are still hitting a hard limit with the execution > ovs commands for setting local vlan tags and clearing flows (or adding the > flow rule for dropping all the traffic). > In some instances this commands slow down a lot, requiring almost 10 > seconds to complete. This adds a delay in interface processing which in > some cases leads to the hideous SSH timeout error (the same we see with bug > 1253896 in normal testing). > It is also worth noting that when this happens sysstat reveal CPU usage is > very close to 100% > > From the neutron side there is little we can do. Introducing parallel > processing for interface, as we do for the l3 agent, is not actually a > solution, since ovs-vswitchd v1.4.x, the one executed on gate tests, is not > multithreaded. If you think the situation might be improved by changing the > logic for handling local vlan tags and putting ports on the dead vlan, I > would be happy to talk about that. How about batching those ovsdb operations? Instead of issueing many ovs-vsctl command, ovs-vsctl -- command0 [args] -- command1 [args] -- ... Then, the number of ovs-vsctl will be reduced and ovs-vsctl issues only single ovsdb transaction. -- Isaku Yamahata <isaku.yamah...@gmail.com> _______________________________________________ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev