> -----Original Message----- > From: Ilya Maximets <[email protected]> > Sent: Thursday 24 March 2022 11:20 > To: [email protected] > Cc: Aaron Conole <[email protected]>; Phelan, Michael > <[email protected]>; Ilya Maximets <[email protected]> > Subject: [PATCH] system-traffic.at: Fix flaky DNAT load balancing test. > > 'conntrack - DNAT load balancing' test fails from time to time because not all > the group buckets are getting hit. > > In short, the test creates a group with 3 buckets with the same weight. It > creates 12 TCP sessions and expects that each bucket will be used at least > once. > However, there is a solid chance that this will not happen. The probability > of > having at least one empty bucket is: > > C(3, 1) x (2/3)^N - C(3, 2) x (1/3)^N > > Where N is the number of distinct TCP sessions. For N=12, the probability is > about 0.023, i.e. there is a 2.3% chance for a test to fail, which is not > great for > CI. > > Increasing the number of sessions to 50 to reduce the probability of failure > down to 4.7e-9. In my testing, the configuration with > 50 TCP sessions didn't fail after 6000 runs. Should be good enough for CI > systems. > > Fixes: 2c66ebe47a88 ("ofp-actions: Allow conntrack action in group buckets.") > Signed-off-by: Ilya Maximets <[email protected]> > --- > tests/system-traffic.at | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/tests/system-traffic.at b/tests/system-traffic.at index > 95383275a..4a7fa49fc 100644 > --- a/tests/system-traffic.at > +++ b/tests/system-traffic.at > @@ -6471,7 +6471,7 @@ on_exit 'ovs-appctl revalidator/purge' > on_exit 'ovs-appctl dpif/dump-flows br0' > > dnl Should work with the virtual IP address through NAT -for i in 1 2 3 4 5 > 6 7 8 9 > 10 11 12; do > +for i in $(seq 1 50); do > echo Request $i > NS_CHECK_EXEC([at_ns1], [wget 10.1.1.64 -t 5 -T 1 --retry-connrefused -v > -o > wget$i.log]) done > -- > 2.34.1
Acked-by: Michael Phelan <[email protected]> _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
