[ovs-dev] [PATCHv2] revalidator: Fetch stats on revalidation failure.

[Ben Pfaff]

Joe, based on Ethan's feedback I'll drop this for now unless you prefer
otherwise.

On Tue, Feb 25, 2014 at 05:37:05PM -0800, Ethan Jackson wrote:
> I'm not sure this patch makes sense in the current code.  If a
> revalidation failed, that's probably because the rules used to create
> the flow changed, in which case we'd be accounting packets to the
> wrong rules.  This is arguable worse than missing the packets all
> together.
> 
> Once we change the code to push stats by maintaining a list of rules
> we need to push, instead of doing a full xlate_actions, I think this
> makes a lot more sense.  In that case, we know we aren't accounting
> anything to the wrong rules.
> 
> Ethan
> 
> 
> On Tue, Feb 25, 2014 at 5:12 PM, Joe Stringer <joestringer at nicira.com> wrote:
> > A flow's statistics could be partially lost in the following situation:
> > * A flow is dumped from the datapath
> > * Some traffic hits that flow
> > * Revalidation fails for that flow
> >
> > Previously, we would delete such a flow without fetching the latest
> > statistics for it, causing the intermediate statistics to be lost. This
> > patch fixes the bug by queueing the flow up for deletion and cleanup
> > along with the other flows that will be deleted.
> >
> > Signed-off-by: Joe Stringer <joestringer at nicira.com>
> > ---
> >  ofproto/ofproto-dpif-upcall.c |    6 ++++--
> >  1 file changed, 4 insertions(+), 2 deletions(-)
> >
> > diff --git a/ofproto/ofproto-dpif-upcall.c b/ofproto/ofproto-dpif-upcall.c
> > index e4f81a1..31d7b9f 100644
> > --- a/ofproto/ofproto-dpif-upcall.c
> > +++ b/ofproto/ofproto-dpif-upcall.c
> > @@ -1534,8 +1534,10 @@ revalidate_udumps(struct revalidator *revalidator, struct list *udumps)
> >          ukey->mark = true;
> >
> >          if (!revalidate_ukey(udpif, udump, ukey)) {
> > -            dpif_flow_del(udpif->dpif, udump->key, udump->key_len, NULL);
> > -            ukey_delete(revalidator, ukey);
> > +            struct dump_op *dop = &ops[n_ops++];
> > +
> > +            dump_op_init(dop, udump->key, udump->key_len, ukey, udump);
> > +            continue;
> >          }
> >
> >          list_remove(&udump->list_node);
> > --
> > 1.7.9.5
> >
> > _______________________________________________
> > dev mailing list
> > dev at openvswitch.org
> > http://openvswitch.org/mailman/listinfo/dev
> _______________________________________________
> dev mailing list
> dev at openvswitch.org
> http://openvswitch.org/mailman/listinfo/dev