This test is inherently racy. It regularly pops up on the CI, and I've
spent one hour chasing a bug that apparently doesn't exist, just because
I'm running it 10 times in a row and it reports from 4 to 8 failures
when built at -O2 and generally even more at -O0. The logs are very
confusing, often reporting that it failed with status 0, with nothing
else wrong. I suspect it might sometimes be the shell command that fails
if it executes faster than haproxy finishes to start up, which would
also explain the relation with the optimization level. E.g:
> Testing with haproxy version: 2.2.0
> # top TEST reg-tests/seamless-reload/abns_socket.vtc FAILED (3.006) exit=2
> # top TEST reg-tests/seamless-reload/abns_socket.vtc FAILED (3.006) exit=2
> # top TEST reg-tests/seamless-reload/abns_socket.vtc FAILED (3.009) exit=2
> # top TEST reg-tests/seamless-reload/abns_socket.vtc FAILED (3.008) exit=2
> # top TEST reg-tests/seamless-reload/abns_socket.vtc FAILED (3.007) exit=2
> # top TEST reg-tests/seamless-reload/abns_socket.vtc FAILED (3.007) exit=2
> 6 tests failed, 0 tests skipped, 4 tests passed
Some of the failures include this, suggesting that some barriers could
help:
---- h1 haproxy h1 PID file check failed:
Could not read PID file '/tmp/haregtests-2020-10-09_11-19-40.kgsDB4/vtc.30539.04dbea7f/h1/pid
Since it has been causing false positives and consumed way more
troubleshooting time than it saved, let's mark it as broken so that it
doesn't waste more time. We can bring it back when someone manages to
figure what the problem is.
The abns_socket in seamless-reload regtest regularly fails in Travis-CI
on smaller machines only (typically the ppc64le and sometimes s390x).
The error always reports an incomplete HTTP header as seen from the
client. And this can occasionally be reproduced on the minicloud ppc64le
image when setting a huge file descriptors limit (1 million).
What happens in fact is the following: depending on the binding order,
some connections from the client might reach the TCP listener on the
old instance and be forwarded to the ABNS listener of the second
instance just being prepared to start up. But due to the huge number
of FDs, setting them up takes slightly more time and the 20ms server
timeout may expire before the new instance finishes its startup. This
can result in an occasional 504, except that since the client timeout
is the same as the server timeout, both sides are closed at the same
time and the client doesn't receive the 504.
In addition a second problem plugs onto this: by default http-reuse is
enabled. Some requests being forwarded to the older instance will be
sent over an already established connection. But the CPU used by the
starting process using many FDs will be taken away from the older
process, whose abns listener will not see a request for more than 20ms,
and will decide to kill the idle client connection. At the same moment
the TCP proxy forwards a request over this closing connection, it
detects the close and silently closes the other side to let the
client retry, which is detected by the vtest client as another case
of empty header. This is easier to reproduce in VMs with few CPUs
(2 or less) and some noisy neighbors such as a few spinning loops in
background.
Let's just increase this tests' timeout to avoid this. While a few
ms are close to the scheduler's granularity, this test is never
supposed to trigger the timeouts so it's safe to go higher without
impacts on the test execution time. At one second the problem seems
impossible to reproduce on the minicloud VMs.
VTest can now enable mworker and mcli with separate flags so lets
update vtc files that need it. This also allows to revert the change
made with 1545a59c ("REGTESTS: make seamless-reload depend on 1.9
and above").
Since latest updates, vtest requires the master CLI when running in
master-worker mode, and this one is only available starting with 1.9.
The seamless reload test is the only one depending on this and now
fails on 1.8, so let's adjust it accordingly.
This patch replaces LEVEL variable by REGTESTS_TYPES variable which is more
mnemonic and human readable. It is uses as a filter to run the reg tests scripts
where a commented #REGTEST_TYPE may be defined to designate their types.
Running the following command:
$ REGTESTS_TYPES=slow,default
will start all the reg tests where REGTEST_TYPE is defines as 'slow' or 'default'.
Note that 'default' is also the default value of REGTEST_TYPE when not specified
dedicated to run all the current h*.vtc files. When REGTESTS_TYPES is not specified
there is no filter at all. All the tests are run.
This patches also defines REGTEST_TYPE with 'slow' value for all the s*.vtc files,
'bug' value for al the b*.vtc files, 'broken' value for all the k*.vtc files.
Add LEVEL #4 regression testing files which is dedicated to
VTC files in relation with bugs they help to reproduce.
At the date of this commit, all VTC files are LEVEL 4 VTC files.
Willy Tarreau
Jerome Magnin
Frédéric Lécaille
Christopher Faulet
PiBa-NL