[ovs-dev] [PATCH] ovs-xapi-sync: Rerun processing when a db update arrives during a commit.

[Ben Pfaff]

Thanks, I pushed it to master and backported all the way to 1.3.

On Thu, Mar 08, 2012 at 11:40:38AM -0800, Justin Pettit wrote:
> It looks good to me.
> 
> --Justin
> 
> 
> On Mar 8, 2012, at 11:12 AM, Ben Pfaff wrote:
> 
> > The logic in ovs-xapi-sync didn't handle the case where ovsdb-server sends
> > a database update before it replies to a transaction that ovs-xapi-sync
> > sent, like this:
> > 
> > ovs-xapi-sync              ovsdb-server
> > -------------              ------------
> > 
> >                      .
> >                      .
> >                      .
> > transaction request  --->
> >                     <---  database contents update
> >                     <---  transaction reply
> >                      .
> >                      .
> >                      .
> > 
> > The update was not lost but ovs-xapi-sync would not process it until the
> > database changed again.
> > 
> > Bug #10082.
> > Reported-by: Krishna Miriyala <krishna at nicira.com>
> > Signed-off-by: Ben Pfaff <blp at nicira.com>
> > ---
> > It's too easy to get this wrong, so I'm working on some patches
> > that make it harder.  In the meantime, I believe that this fixes
> > the observed problem.
> > 
> > Thanks,
> > 
> > Ben.
> > 
> > .../usr_share_openvswitch_scripts_ovs-xapi-sync    |    5 ++++-
> > 1 files changed, 4 insertions(+), 1 deletions(-)
> > 
> > diff --git a/xenserver/usr_share_openvswitch_scripts_ovs-xapi-sync b/xenserver/usr_share_openvswitch_scripts_ovs-xapi-sync
> > index 7132726..0ffccc2 100755
> > --- a/xenserver/usr_share_openvswitch_scripts_ovs-xapi-sync
> > +++ b/xenserver/usr_share_openvswitch_scripts_ovs-xapi-sync
> > @@ -272,8 +272,10 @@ def main():
> >     bridges = {}                # Map from bridge name to xs_network_uuids
> >     iface_ids = {}              # Map from xs-vif-uuid to iface-id
> >     vm_ids = {}                 # Map from xs-vm-uuid to vm-id
> > +    seqno = idl.change_seqno    # Sequence number when we last processed the db
> >     while True:
> > -        if not force_run and not idl.run():
> > +        idl.run()
> > +        if not force_run and seqno == idl.change_seqno:
> >             poller = ovs.poller.Poller()
> >             idl.wait(poller)
> >             poller.block()
> > @@ -285,6 +287,7 @@ def main():
> >             iface_ids = {}
> >             vm_ids = {}
> >             force_run = False
> > +        seqno = idl.change_seqno
> > 
> >         txn = ovs.db.idl.Transaction(idl)
> > 
> > -- 
> > 1.7.2.5
> > 
> > _______________________________________________
> > dev mailing list
> > dev at openvswitch.org
> > http://openvswitch.org/mailman/listinfo/dev
>