Yes, the output is OK. In fact, if you change the time/warp in ofproto-dpif.at so that it only advances the monotonic clock by 2 seconds during the test instead of 3 (see below), then it flushes out the same number of counter samples, and the only differences that appear in tests/testsuite.dir/1075/testsuite.log are to the datagram sequence numbers for the counter samples. Very much as expected.
diff --git a/tests/ofproto-dpif.at b/tests/ofproto-dpif.at index 8e5fde6..143c868 100644 --- a/tests/ofproto-dpif.at +++ b/tests/ofproto-dpif.at @@ -5267,7 +5267,7 @@ m4_define([CHECK_SFLOW_SAMPLING_PACKET], dnl sleep long enough to get more than one counter sample dnl from each datasource so we can check sequence numbers - ovs-appctl time/warp 3000 100 + ovs-appctl time/warp 2000 100 OVS_VSWITCHD_STOP OVS_APP_EXIT_AND_WAIT([test-sflow]) ------ Neil McKee InMon Corp. http://www.inmon.com On Fri, Sep 2, 2016 at 12:51 PM, Ben Pfaff <b...@ovn.org> wrote: > I see the failing tests. > > If you can read the new results of the tests and verify for me that > they're still a correct set of results, then I'll push a fix that > updates the expected results. > > On Fri, Sep 02, 2016 at 12:03:21PM -0700, Neil McKee wrote: >> This one perturbs the output ordering just enough to fail two of the >> sflow unit tests. Sorry I didn't notice that before. I'll post >> another patch for that. >> >> Neil >> ------ >> Neil McKee >> InMon Corp. >> http://www.inmon.com >> >> >> On Fri, Sep 2, 2016 at 11:47 AM, Ben Pfaff <b...@ovn.org> wrote: >> > On Mon, Aug 29, 2016 at 03:32:41PM -0700, Neil McKee wrote: >> >> This patch changes the order of the steps that are followed >> >> every second in the sFlow agent. By moving the receiver_tick() >> >> step to the end, we ensure that any counters that were polled >> >> during the poller_tick() step are flushed immediately to the >> >> sFlow collector. This eliminates what was a variable time-delay >> >> between counters being polled and being flushed. >> >> >> >> The variable time-delay that this eliminates could be up to >> >> a second because counters lingering in the output buffer could be >> >> flushed at any time by the arrival of random packet-samples. >> >> >> >> Since the sFlow standard does not require that a poll-timestamp be sent >> >> along with the counters the collector must use his receive-time as the >> >> timestamp, so that extra second of variable delay was "stretching or >> >> shrinking" the time between successive counter readings. This >> >> affected any counter-rate calculation that was based only on the delta >> >> between sucessive samples. The effect was small with a polling >> >> interval of 60 seconds: just +/- 2%. But the effect grew larger >> >> when faster polling was configured. For example, if the counters >> >> were pushed every 5 seconds then the instantaneous rate >> >> calculations could wander by +/- 20%. For a thorough analysis >> >> of this problem, see Rick Jones' paper: >> >> >> >> "High Frequency sFlow v5 Counter Sampling" >> >> ftp://ftp.netperf.org/papers/high_freq_sflow/hf_sflow_counters.pdf >> >> >> >> So this patch makes it possible to obtain usable results even >> >> when high-frequency polling is configured. >> >> >> >> Signed-off-by: Neil McKee <neil.mc...@inmon.com> >> > >> > Thanks, applied to master and branch-2.6. _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
