On Fri, Jul 12, 2019 at 11:46 AM Lorenzo Bianconi < [email protected]> wrote: > > > On Thu, Jul 11, 2019 at 05:48:42PM +0200, Lorenzo Bianconi wrote: > > > There are situations where arrival of certain types of traffic into OVS > > > does not warrant a "typical" action, such as output to a specific port > > > or dropping. Rather, the decision about what to do needs to be left to a > > > CMS. > > > > > > The series here introduces a new table, Controller_Event, for this > > > purpose. Traffic into OVS can raise a 'controller' event that results in > > > a Controller_Event being written to the southbound database. The > > > intention is for a CMS to see the events and take some sort of action. > > > When the CMS has seen the event and taken appropriate action, then it > > > can remove the correponding row in Controller_Event table. > > > > The series seems OK to me. However: do we need to do something to > > rate-limit sending messages to ovn-controller? It seems like a flood of > > packets could trigger a flood of OpenFlow messages to ovn-controller, > > which could result in poor service. > > > > I suspect the answer is "yes", but maybe it is "yes, but it's OK for > > 2.12 and we can add rate-limiting in the next release". > > > > What do you think? > > Hi Ben, > > in pinctrl_handle_empty_lb_backends_opts() I added a limit to event_table > size. If we overcame this limit, ovn-controller discards the received event > and it does not notify main thread. Do you think we need some more sophisticated? > If so, and if you agree, I think we can work on it after 2.12 release. > > Regards, > Lorenzo > > > > > Thanks, > > > > Ben. > _______________________________________________ > dev mailing list > [email protected] > https://mail.openvswitch.org/mailman/listinfo/ovs-dev
Hi Lorenzo, I am worried about the flooding, too. Thanks for adding the limit for event_table. It is good that it won't notify the main thread and update SB DB continuously. However, pinctrl thread would still get overloaded if controller messages keep flooding to ovn-controller. Would it be better to use meter action in the flow to ratelimit the messages to ovn-controller, something like what ACL log ratelimit does? I think it is ok for the ratelimit improvement to be in next release, since the feature is not enabled by default (i.e. controller_event opt in NB global is not set). Thanks, Han _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
