[ovs-dev] [PATCH] ofproto: Return error codes for Rule insertions"

Ben Pfaff blp at ovn.org
Tue Jul 10 16:32:49 UTC 2018


OK.

On Tue, Jul 10, 2018 at 02:58:47PM +0530, Aravind Prasad wrote:
> Hi Ben/All,
> 
> If possible, Kindly hold reviewing this patch for now. Expecting an
> approval from my Org. Sorry for the inconvenience caused and thanks for the
> support.
> 
> Will get back and intimate for the review as soon as possible after the
> approval (expecting it to take not more than a week).  And thanks again for
> understanding.
> 
> Thanks,
> Aravind Prasad S
> 
> On Tue, Jul 10, 2018 at 7:06 AM Aravind Prasad <raja.avi at gmail.com> wrote:
> 
> >
> > Currently, rule_insert() API doesnot have return value. There are some
> > possible
> > > scenarios where rule insertions can fail at run-time even though the
> > static
> > > checks during rule_construct() had passed previously.
> > > Some possible scenarios for failure of rule insertions:
> > > **) Rule insertions can fail dynamically in Hybrid mode (both Openflow
> > and
> > > Normal switch functioning coexist) where the CAM space could get suddenly
> > > filled up by Normal switch functioning and Openflow gets devoid of
> > > available space.
> > > **) Some deployments could have separate independent layers for HW rule
> > > insertions and application layer to interact with OVS. HW layer
> > > could face any dynamic issue during rule handling which application could
> > > not have predicted/captured in rule-construction phase.
> > > Rule-insert errors for bundles are not handled in this pull-request.
> > > Will be handled in upcoming pull request.
> >
> > >> I don't think that ofproto-dpif can ever see such a failure.  Are you
> > >> planning to submit an ofproto provider that exercises this behavior?
> >
> > Hi Ben,
> >
> > These type of errors are possible in actual Hardware implementations.
> > It is possible that ofproto and netdev providers could be implemented
> > for a actual HW.
> > Usually, in such cases, in the rule construct phase, all the static
> > checks like verifying the qualifiers and actions could be done and the
> > other related verifications.
> > But during the rule insert phase, it is possible that the rule insertion
> > may get failed in HW (runtime errors, HW errors and so on).
> > Hence, we need a way to rollback for rule-insert phase also.
> > Kindly let me know your views.
> >
> > Thanks,
> > Aravind Prasad S
> >
> >
> > On Tue, Jul 10, 2018 at 3:45 AM Ben Pfaff <blp at ovn.org> wrote:
> >
> >> On Mon, Jul 09, 2018 at 01:02:08PM +0530, Aravind Prasad S wrote:
> >> > Currently, rule_insert() API doesnot have return value. There are some
> >> possible
> >> > scenarios where rule insertions can fail at run-time even though the
> >> static
> >> > checks during rule_construct() had passed previously.
> >> > Some possible scenarios for failure of rule insertions:
> >> > **) Rule insertions can fail dynamically in Hybrid mode (both Openflow
> >> and
> >> > Normal switch functioning coexist) where the CAM space could get
> >> suddenly
> >> > filled up by Normal switch functioning and Openflow gets devoid of
> >> > available space.
> >> > **) Some deployments could have separate independent layers for HW rule
> >> > insertions and application layer to interact with OVS. HW layer
> >> > could face any dynamic issue during rule handling which application
> >> could
> >> > not have predicted/captured in rule-construction phase.
> >> > Rule-insert errors for bundles are not handled in this pull-request.
> >> > Will be handled in upcoming pull request.
> >> >
> >> > Signed-off-by: Aravind Prasad S <raja.avi at gmail.com>
> >>
> >> I don't think that ofproto-dpif can ever see such a failure.  Are you
> >> planning to submit an ofproto provider that exercises this behavior?
> >>
> >> Thanks,
> >>
> >> Ben.
> >>
> >


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