[ovs-discuss] Unexpected behavior of counters when installing new flow

[Ben Pfaff]

That helps narrow down the possible problems.

Do you have to use 1.7?  It would be helpful to know if you see the
same problem with 1.9, which is a series that we're maintaining
long-term.

On Wed, May 01, 2013 at 11:05:06AM +0200, Tmusic wrote:
> Hi,
> 
> First to make sure there are no misunderstandings: the entries in the
> switch are installed by the POX controller (as you have probably already
> noticed).
> 
> For the test below (what you proposed) I added the /31 entry by hand to
> make sure the issue is not due to some controller logic issue. And just a
> remark: traffic is same as in the previous mail but at 1000 packet/s to
> make it easier to interpret the values.
> 
> So starting traffic, let controller install entries and dump after a some
> time:
> 
> NXST_FLOW reply (xid=0x4):
>  cookie=0x3e8, duration=23.611s, table=0, n_packets=28, n_bytes=16520,
> idle_age=0, icmp,nw_src=10.1.6.0/30,nw_dst=10.1.4.0/30 actions=output:1
>  cookie=0x0, duration=52.033s, table=0, n_packets=31, n_bytes=1860,
> idle_age=0, priority=65000,dl_dst=01:23:20:00:00:01,dl_type=0x88cc
> actions=CONTROLLER:65535
>  cookie=0x3eb, duration=18.558s, table=0, n_packets=0, n_bytes=0,
> idle_age=18, arp,dl_src=00:25:90:64:f9:3e,dl_dst=90:e2:ba:00:9f:86
> actions=output:2
>  cookie=0x3ea, duration=18.598s, table=0, n_packets=1, n_bytes=60,
> idle_age=18, arp,dl_src=90:e2:ba:00:9f:86,dl_dst=00:25:90:64:f9:3e
> actions=output:1
>  cookie=0x3e9, duration=23.606s, table=0, n_packets=23544,
> n_bytes=25097904, idle_age=0, udp,nw_src=
> 10.1.4.0/30,nw_dst=10.1.6.0/30,tp_src=20,tp_dst=1000 actions=output:2
> 
> 
> Kill traffic generation and dump:
> 
> NXST_FLOW reply (xid=0x4):
>  cookie=0x3e8, duration=40.183s, table=0, n_packets=30, n_bytes=17700,
> idle_age=15, icmp,nw_src=10.1.6.0/30,nw_dst=10.1.4.0/30 actions=output:1
>  cookie=0x0, duration=68.605s, table=0, n_packets=41, n_bytes=2460,
> idle_age=0, priority=65000,dl_dst=01:23:20:00:00:01,dl_type=0x88cc
> actions=CONTROLLER:65535
>  cookie=0x3eb, duration=35.13s, table=0, n_packets=1, n_bytes=60,
> idle_age=10, arp,dl_src=00:25:90:64:f9:3e,dl_dst=90:e2:ba:00:9f:86
> actions=output:2
>  cookie=0x3ea, duration=35.17s, table=0, n_packets=2, n_bytes=120,
> idle_age=10, arp,dl_src=90:e2:ba:00:9f:86,dl_dst=00:25:90:64:f9:3e
> actions=output:1
>  cookie=0x3e9, duration=40.178s, table=0, n_packets=*25049, n_bytes=26702234
> *, idle_age=15, udp,nw_src=
> 10.1.4.0/30,nw_dst=10.1.6.0/30,tp_src=20,tp_dst=1000 actions=output:2
> 
> Starting traffic again and dump:
> 
>  cookie=0x3e8, duration=64.755s, table=0, n_packets=55, n_bytes=32450,
> idle_age=0, icmp,nw_src=10.1.6.0/30,nw_dst=10.1.4.0/30 actions=output:1
>  cookie=0x0, duration=93.177s, table=0, n_packets=54, n_bytes=3240,
> idle_age=3, priority=65000,dl_dst=01:23:20:00:00:01,dl_type=0x88cc
> actions=CONTROLLER:65535
>  cookie=0x3eb, duration=59.702s, table=0, n_packets=3, n_bytes=180,
> idle_age=9, arp,dl_src=00:25:90:64:f9:3e,dl_dst=90:e2:ba:00:9f:86
> actions=output:2
>  cookie=0x3ea, duration=59.742s, table=0, n_packets=4, n_bytes=240,
> idle_age=9, arp,dl_src=90:e2:ba:00:9f:86,dl_dst=00:25:90:64:f9:3e
> actions=output:1
>  cookie=0x3e9, duration=64.75s, table=0, n_packets=44305, n_bytes=47229130,
> idle_age=0, udp,nw_src=10.1.4.0/30,nw_dst=10.1.6.0/30,tp_src=20,tp_dst=1000actions=output:2
> 
> 
> Adding entry by hand (sudo ovs-ofctl add-flow br0
> cookie=0x3e8,table=0,udp,nw_src=
> 10.1.4.0/31,nw_dst=10.1.6.2/31,tp_src=20,tp_dst=1000,priority=65100,actions=output:2)
> and dump:
> 
> NXST_FLOW reply (xid=0x4):
>  cookie=0x3e8, duration=1.584s, table=0, n_packets=38256, n_bytes=40780896,
> idle_age=0, priority=65100,udp,nw_src=
> 10.1.4.0/31,nw_dst=10.1.6.2/31,tp_src=20,tp_dst=1000 actions=output:2
>  cookie=0x3e8, duration=83.559s, table=0, n_packets=74, n_bytes=43660,
> idle_age=0, icmp,nw_src=10.1.6.0/30,nw_dst=10.1.4.0/30 actions=output:1
>  cookie=0x0, duration=111.981s, table=0, n_packets=67, n_bytes=4020,
> idle_age=0, priority=65000,dl_dst=01:23:20:00:00:01,dl_type=0x88cc
> actions=CONTROLLER:65535
>  cookie=0x3eb, duration=78.506s, table=0, n_packets=4, n_bytes=240,
> idle_age=3, arp,dl_src=00:25:90:64:f9:3e,dl_dst=90:e2:ba:00:9f:86
> actions=output:2
>  cookie=0x3ea, duration=78.546s, table=0, n_packets=5, n_bytes=300,
> idle_age=3, arp,dl_src=90:e2:ba:00:9f:86,dl_dst=00:25:90:64:f9:3e
> actions=output:1
>  cookie=0x3e9, duration=83.554s, table=0,* n_packets=25049, n_bytes=26702234
> *, idle_age=2, udp,nw_src=
> 10.1.4.0/30,nw_dst=10.1.6.0/30,tp_src=20,tp_dst=1000 actions=output:2
> 
> So indeed, it seems to return to the values when the flow was idle.
> 
> Does this help?
> 
> Kind regards,
> 
> Tim
> 
> 
> 
> 
> 
> 2013/5/1 Ben Pfaff <blp at nicira.com>
> 
> > On Tue, Apr 30, 2013 at 12:49:26PM +0200, Tmusic wrote:
> > > Let me post some more debug information then:
> >
> > [...]
> >
> > > Does this provides more useful information?
> >
> > It gets me past the "I don't really believe this, it must be some
> > misunderstanding" hurdle ;-)
> >
> > Are you willing to do a few experiments?  Here is one idea:
> >
> > 1. Start your stream and add the initial flow to the flow table (in
> >    whatever order you like).  Let it run for a while, a few seconds at
> >    least.
> >
> > 2. Dump stats with "ovs-ofctl dump-flows".
> >
> > 3. Stop your stream and "sleep 5" (or just wait 5 or more seconds
> >    patiently).
> >
> > 4. Dump stats with "ovs-ofctl dump-flows".
> >
> > 5. Restart your stream.  Let it run for a while, a few seconds at least.
> >
> > 6. Add your higher-priority flow to the flow table.  Let the stream run
> >    for a while, a few seconds at least.
> >
> > 7. Dump stats with "ovs-ofctl dump-flows".
> >
> > The question I'm trying to answer is whether the low-priority flow's
> > stats drop to zero in step 7, or to the values seen in step 2, or
> > something else entirely.
> >
> > Thanks,
> >
> > Ben.
> >