Comment 0 for bug 1582238

In current flow_classifiers API design , If multiple flow_classifiers are configured in port chain ,the classification rule applied on the basis of order of configuration . If admin need to change the flow classifier order , admin have to delete existing chain and re-config new service chain .

This proposal introduce new "priority” field in flow-classifier to correct/update ordering of flows.

Reference :

OVS already supporting this priority field in flow rules .

http://openvswitch.org/support/dist-docs/ovs-ofctl.8.txt

priority=value
              The priority at which a wildcarded entry will match in compari‐
              son to others. value is a number between 0 and 65535, inclu‐
              sive. A higher value will match before a lower one. An exact-
              match entry will always have priority over an entry containing
              wildcards, so it has an implicit priority value of 65535. When
              adding a flow, if the field is not specified, the flow's prior‐
              ity will default to 32768.

              OpenFlow leaves behavior undefined when two or more flows with
              the same priority can match a single packet. Some users expect
              ``sensible'' behavior, such as more specific flows taking prece‐
              dence over less specific flows, but OpenFlow does not specify
              this and Open vSwitch does not implement it. Users should
              therefore take care to use priorities to ensure the behavior
              that they expect.