On 1 Mar 2024, at 13:42, Ilya Maximets wrote:
> On 3/1/24 12:37, Ilya Maximets wrote:
>> With a new runner update, GitHub Actions had a kernel update.
>> And it seems like something changed between kernels 6.2 and 6.5
>> so this test now fails very frequently.
>>
>> I can reproduce the same issue on RHEL 9, and I can't reproduce
>> it on Ubuntu 23.04 (kernel 6.2).
>>
>> The test is creating a NAT with a single address+port pair in
>> an attempt to simulate an address space exhaustion. It is
>> expected that a first connection with wget leaves a conntrack
>> entry in a TIME_WAIT state and the second wget should fail
>> as long as this entry remains, because the only available
>> address+port pair is already taken.
>>
>> However, for some reason, very frequently (not always!) the
>> second connection replaces the first conntrack entry with a
>> new one and connection succeeds. There is still only one
>> connection in the conntrack at any single moment in time, so
>> there is seemingly no issue with the NAT, but the behavior
>> is unexpected and the test fails.
>>
>> Disable the test in CI until we figure out how to fix the
>> kernel (if it is a kernel bug) or the test.
>
> Marcelo pointed out the following change that went into 6.5 kernel:
> https://lore.kernel.org/netdev/20230626064749.75525-7-pa...@netfilter.org/
>
> It looks like this test is not going to work anymore as new connections
> are now allowed to evict closing ones on collisions.
>
> We need to re-think the test, i.e. we have to keep the first connection
> open while we're trying to make the second one, so it is not evicted.
Paolo, can you take a look at fixing the test case? Do you want an FDP issue
for this?
>>
>> Signed-off-by: Ilya Maximets <i.maxim...@ovn.org>
>> ---
The change looks good for now.
Acked-by: Eelco Chaudron <echau...@redhat.com>
>> tests/system-traffic.at | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> diff --git a/tests/system-traffic.at b/tests/system-traffic.at
>> index 98e494abf..07d09b912 100644
>> --- a/tests/system-traffic.at
>> +++ b/tests/system-traffic.at
>> @@ -6388,6 +6388,7 @@ OVS_TRAFFIC_VSWITCHD_STOP
>> AT_CLEANUP
>>
>> AT_SETUP([conntrack - SNAT with port range with exhaustion])
>> +OVS_CHECK_GITHUB_ACTION()
>> CHECK_CONNTRACK()
>> CHECK_CONNTRACK_NAT()
>> OVS_TRAFFIC_VSWITCHD_START()
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