On Fri, Aug 08, 2014 at 05:39:26PM +0530, Shashwat Srivastava wrote: > I want to incorporate "Eviction mechanism" as per the openflow > specification 1.4 > > As per the openflow specification 1.4 (Section 7.3.4.1), there are three > eviction flags: importance,lifetime and other. If importance flag is the > only flag set (lifetime and others not set), eviction is performed > strictly in order of importance field specified in flow entry, that is > flow entry with lower importance will be evicted before flow entry with > higher importance. > > But if all flow entries are of same importance, it has been specified that > "the eviction mechanism is switch defined ", therefore it is not possible > to predict in which order flow entries of same importance will get > evicted. > At present (without implementation of eviction), when a flow table is > full, new flow entries are not inserted in the flow table and an error is > returned to the controller, controller needs time to work on flow table > and thus may cause a disruption of service. Does this means that, users > should therefore take care to use importance field wisely to ensure the > behaviour they expect and avoid disruption of service. It would be great > help if someone could explain how eviction will be done in this case. > > Also kindly suggest action when both the flags for importance and lifetime > are simultaneously set, as this is missing in the openflow specification > 1.4
Open vSwitch already implements eviction that can be configured to meet the requirements of "other" and "lifetime" based eviction. I believe that all that we would have to do to comply with OpenFlow 1.4 in this area is to make the feature configurable via the OpenFlow 1.4 table_mod message. OpenFlow 1.4 does not appear to define how "importance" interacts with the "lifetime" and "other" eviction policies. If we implement importance-based eviction, we will have to decide what would be most useful for our users. _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
