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| From: | Wainer dos Santos Moschetta |
| Subject: | Re: [Qemu-devel] [PATCH 1/2] Acceptance tests: exclude "flaky" tests |
| Date: | Fri, 5 Jul 2019 16:01:37 -0300 |
| User-agent: | Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.5.2 |
On 06/30/2019 02:51 PM, Cleber Rosa wrote:
On Fri, Jun 28, 2019 at 05:43:09PM -0300, Wainer dos Santos Moschetta wrote:On 06/21/2019 11:38 AM, Cleber Rosa wrote:On Fri, Jun 21, 2019 at 09:03:33AM +0200, Philippe Mathieu-Daudé wrote:On 6/21/19 8:09 AM, Cleber Rosa wrote:It's a fact that some tests may not be 100% reliable in all environments. While it's a tough call to remove a useful test that from the tree because it may fail every 1/100th time (or so), having human attention drawn to known issues is very bad for humans and for the projects they manage. As a compromise solution, this marks tests that are known to have issues, or that exercises known issues in QEMU or other components, and excludes them from the entry point. As a consequence, tests marked as "flaky" will not be executed as part of "make check-acceptance". Because such tests should be forgiven but never be forgotten, it's possible to list them with (assuming "make check-venv" or "make check-acceptance" has already initiatilized the venv): $ ./tests/venv/bin/avocado list -t flaky tests/acceptanceIt needs a Make target to run those flaky tests (If we ever agree on this idea of flaky tests). Other Avocado flags are passed (e.g. -t for tags) that can happen to fail tests on their absent. One clear example is the spice test on patch 02 of this series...I was trying to avoid having so make "check-acceptance-*" rules that just choosing one would be harder than writing an Avocado command line from scratch... but I think you have a point here. For once, this can be used in a Travis job with an special "allow_failures" option set.
Checking if I understood: you are proposing to keep running the flaky on Travis which might get failing most of time (but Travis won't flag error). Until someone fix them and remove the "flaky" tag so putting them on the (virtual) "stable" tests group? If so, I am ok with this approach while we don't have a better solution in place.
Side note: check-acceptance seems to get growing in complexity that I worry will end up in pitfalls. is a Make target the proper way to implement complex test runs (I don't think so). Perhaps Avocado runner concept could help somehow?I guess you mean the Avocado Job concept, and writing your own runner based on those APIs. If so, then absolutely yes. I've shared with Eduardo some of the use cases that we can solve much easily. But, we need to finish the last bits on the Avocado side, properly document and support the API before attempting to use it here on QEMU.
I just realized that test runner is another thing in Avocado's jargon: https://avocado-framework.readthedocs.io/en/70.0/GetStartedGuide.html#running-tests-with-an-external-runner Ok, I'm looking forward those improvements on Avocado API. :) - Wainer
The current list of tests marked as flaky are a result of running the entire set of acceptance tests around 20 times. The results were then processed with a helper script[1]. That either confirmed known issues (in the case of aarch64 and arm)[2] or revealed new ones (mips). This also bumps the Avocado version to one that includes a fix to the parsing of multiple and mix "key:val" and simple tag values. [1] https://raw.githubusercontent.com/avocado-framework/avocado/master/contrib/scripts/summarize-job-failures.py [2] https://bugs.launchpad.net/qemu/+bug/1829779 Signed-off-by: Cleber Rosa <address@hidden> --- docs/devel/testing.rst | 17 +++++++++++++++++ tests/Makefile.include | 6 +++++- tests/acceptance/boot_linux_console.py | 2 ++ tests/acceptance/linux_ssh_mips_malta.py | 2 ++ tests/requirements.txt | 2 +- 5 files changed, 27 insertions(+), 2 deletions(-) diff --git a/docs/devel/testing.rst b/docs/devel/testing.rst index da2d0fc964..ff4d8e2e1c 100644 --- a/docs/devel/testing.rst +++ b/docs/devel/testing.rst @@ -574,6 +574,23 @@ may be invoked by running: tests/venv/bin/avocado run $OPTION1 $OPTION2 tests/acceptance/ +Tagging tests +------------- + +flaky +~~~~~ + +If a test is known to fail intermittently, even if only every one +hundredth time, it's highly advisable to mark it as a flaky test. +This will prevent these individual tests from failing much larger +jobs, will avoid human interaction and time wasted to verify a known +issue, and worse of all, can lead to the discredit of automated +testing. + +To mark a test as flaky, add to its docstring.:: + + :avocado: tags=flakyI certainly disagree with this patch, failing tests have to be fixed. Why not tag all the codebase flaky and sing "happy coding"?That's a great idea! :) Now, seriously, I also resisted this for quite a long time. The reality, though, is that intermittent failures will continue to appear, and letting tests (and jobs, and CI pipelines, and whatnot) fail is a very bad idea. We all agree that real fixes are better than this, but many times they don't come quickly.It seems to me that flaky test is just a case in a broaden scenario: run (or not) grouped tests. You may have tests indeed broken or that takes considerable time (those tagged "slow") which one may fairly want to exclude from `make check-acceptance` as well. Thus some way to group tests plus define run inclusion/exclusion patterns seems the ultimate goal here.Yes, you have a point about "yet another set of tests". I think that, whenever we break the limit of expressiveness with something like the current incarnation of tags (which shouldn't need much explanation) then it's time to rely on something that has all the expressiveness and doesn't impose any other restrictions. I'm refering to the previous idea about using the Job API, and creating customized runner that, with the expressiveness of Python code, can choose tests for different scenarios. What I don't think we should try to do, is to come up with yet another language, or YAML parser, or anything along those lines.Anyway if this get accepted, 'flaky' tags must have the intermittent failure well described, and a Launchpad/Bugzilla tracking ticket referenced.And here you have a key point that I absolutely agree with. The "flaky" approach can either poison a lot of tests, and be seen as quick way out of a difficult issue revealed by a test. Or, it can serve as an effective tool to keep track of these very important issues. If we add: # https://bugs.launchpad.net/qemu/+bug/1829779 :avocado: flaky Topped with some human, I believe this can be very effective. This goes without saying, but comments here are very much welcome.I agree that all flaky test should have a tracking bug. In the end it represents a technical debit that we should address. - WainerYep, that I also agree 100%. - Cleber.- Cleber.+ Manual Installation ------------------- diff --git a/tests/Makefile.include b/tests/Makefile.include index db750dd6d0..4c97da2878 100644 --- a/tests/Makefile.include +++ b/tests/Makefile.include @@ -1125,7 +1125,11 @@ TESTS_RESULTS_DIR=$(BUILD_DIR)/tests/results # Any number of command separated loggers are accepted. For more # information please refer to "avocado --help". AVOCADO_SHOW=app -AVOCADO_TAGS=$(patsubst %-softmmu,-t arch:%, $(filter %-softmmu,$(TARGET_DIRS))) + +# Additional tags that are added to each occurence of "--filter-by-tags" +AVOCADO_EXTRA_TAGS := ,-flaky + +AVOCADO_TAGS=$(patsubst %-softmmu,--filter-by-tags=arch:%$(AVOCADO_EXTRA_TAGS), $(filter %-softmmu,$(TARGET_DIRS))) ifneq ($(findstring v2,"v$(PYTHON_VERSION)"),v2) $(TESTS_VENV_DIR): $(TESTS_VENV_REQ) diff --git a/tests/acceptance/boot_linux_console.py b/tests/acceptance/boot_linux_console.py index 32159503e9..6bd5c1ab53 100644 --- a/tests/acceptance/boot_linux_console.py +++ b/tests/acceptance/boot_linux_console.py @@ -249,6 +249,7 @@ class BootLinuxConsole(Test): """ :avocado: tags=arch:aarch64 :avocado: tags=machine:virt + :avocado: tags=flaky """ kernel_url = ('https://download.fedoraproject.org/pub/fedora/linux/' 'releases/29/Everything/aarch64/os/images/pxeboot/vmlinuz') @@ -270,6 +271,7 @@ class BootLinuxConsole(Test): """ :avocado: tags=arch:arm :avocado: tags=machine:virt + :avocado: tags=flaky """ kernel_url = ('https://download.fedoraproject.org/pub/fedora/linux/' 'releases/29/Everything/armhfp/os/images/pxeboot/vmlinuz') diff --git a/tests/acceptance/linux_ssh_mips_malta.py b/tests/acceptance/linux_ssh_mips_malta.py index aafb0c39f6..ae70b658e0 100644 --- a/tests/acceptance/linux_ssh_mips_malta.py +++ b/tests/acceptance/linux_ssh_mips_malta.py @@ -208,6 +208,7 @@ class LinuxSSH(Test): :avocado: tags=machine:malta :avocado: tags=endian:big :avocado: tags=device:pcnet32 + :avocado: tags=flaky """ kernel_url = ('https://people.debian.org/~aurel32/qemu/mips/' 'vmlinux-3.2.0-4-5kc-malta') @@ -222,6 +223,7 @@ class LinuxSSH(Test): :avocado: tags=machine:malta :avocado: tags=endian:little :avocado: tags=device:pcnet32 + :avocado: tags=flaky """ kernel_url = ('https://people.debian.org/~aurel32/qemu/mipsel/' 'vmlinux-3.2.0-4-5kc-malta') diff --git a/tests/requirements.txt b/tests/requirements.txt index 3ae0e29ad7..58d63d171f 100644 --- a/tests/requirements.txt +++ b/tests/requirements.txt @@ -1,5 +1,5 @@ # Add Python module requirements, one per line, to be installed # in the tests/venv Python virtual environment. For more info, # refer to: https://pip.pypa.io/en/stable/user_guide/#id1 -avocado-framework==68.0 +avocado-framework==69.1 paramiko
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