Hi Ben, The current hard-coded default select group implementation requires every single L4 flow to be load-balanced in an upcall and creates a dedicated megaflow for every 5-tuple. This is clearly not scalable in deployments where the number of parallel L4 flows and the L4 flow setup rate is unknown and cannot be controlled (e.g. in Telco cloud deployments where the VNFs carry end-user traffic).
We need a scalable select group implementation to implement distributed ECMP L3 forwarding in OVS. The dp_hash based implementation is mostly already in place, thanks to Jarno, but its use is unfortunately tied to an OF 1.5 Group Mod extension that our controllers do not support. Our aim with this proposal is to provide a scalable select group implementation in OVS for any OpenFlow controller. As there is no functional difference between the original selection method and the dp_hash based one, I don't see a reason why the controller should have to be involved for choosing one or the other. This is different in nature from the extension to specify the hash fields for the bucket selection. As Cloud provider we would like to be able to configure OVS to by default use apply the scalable dp_hash selection method, unless the controller specifies something else. A natural place seems to be to add this as a bridge property. Regards, Jan N.B. The pre-OF 1.5 Group Mod message simply has no extension mechanism to carry addition group properties. We would have to add a proprietary new NX Group Mod message, which would not make life much simpler for controllers. > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Ben Pfaff > Sent: Monday, 25 September, 2017 17:31 > To: Nitin Katiyar <[email protected]> > > This proposes adding a default selection method that could be set via > OVSDB. This would probably work (I have not thought through the > implications), but the usual way that we would solve this kind of thing > in OVS is by making the features of the OF1.5 group_mod available in > earlier versions. _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
