[TESTBUG] runtime/containers/docker/TestCPUAwareness.java failed in docker not supporting --cpus

[Bob Vandette]

Since —cpus is just a shortcut for of setting both --cpu-period and --cpu-quota”, I’d
be ok with removing this test.  The tests are intended to test the container/cgroup
configuration detection logic and not to verify that docker works correctly.

An alternate solution would be to add version detection to the Docker test check in
DockerTestUtils.java .   We already exec “docker ps” to see if docker is available
and enabled.

% docker --version
Docker version 17.03.1-ce, build 276fd32


Bob.



> On Jan 22, 2019, at 10:19 PM, Ao Qi <aoqi at loongson.cn> wrote:
> 
> On Wed, Jan 23, 2019 at 10:55 AM David Holmes <david.holmes at oracle.com> wrote:
>> 
>> On 23/01/2019 11:58 am, Ao Qi wrote:
>>> Hi David,
>>> 
>>> On Wed, Jan 23, 2019 at 5:24 AM David Holmes <david.holmes at oracle.com> wrote:
>>>> 
>>>> cc'ing Bob as our containers expert ...
>>>> 
>>>> On 23/01/2019 1:10 am, Ao Qi wrote:
>>>>> Hi,
>>>>> 
>>>>> --cpus is available in Docker 1.13 and higher [1], so
>>>>> runtime/containers/docker/TestCPUAwareness.java failed in docker which
>>>>> does not support --cpus.
>>>>> 
>>>>> Webrev: http://cr.openjdk.java.net/~aoqi/docker/webrev.00/
>>>>> 
>>>>> This patch skips the test if --cpus is not supported. I tested
>>>>> runtime/containers/docker/TestCPUAwareness.java on a Fedora 25 (Docker
>>>>> version 1.12.6, build ae7d637/1.12.6, not supporting --cpus) and
>>>>> Ubuntu 16.04 (Docker version 17.03.2-ce, build f5ec1e2, supporting
>>>>> --cpus)
>>>> 
>>>> The patch causes the test to pass if launching Docker fails for any
>>>> reason so that is not good.
>>>> 
>>> 
>>> I tested two versions of docker which does not support --cpus. Their
>>> exit values when using --cpus are 2 and 125, and outputs are:
>>> 
>>> flag provided but not defined: --cpus
>>> See 'docker run --help'.
>>> 
>>> and
>>> 
>>> unknown flag: --cpus
>>> See 'docker run --help'.
>>> 
>>> My initial thought was that the else condition of
>>> "output.getExitValue() == 0" should match the condition of "--cpus not
>>> supported". Firstly I used output.shouldMatch("docker run --help"),
>>> but I am not sure if all the docker version behaves this way when
>>> --cpus is not supported and "docker run --help" does not certainly
>>> indicate "--cpus not supported", so I removed the else condition.
>> 
>> I think we need to try and find a way to clearly identifyt eh failing
>> condition. Is there are "docker --version" we coudl check?
>> 
> 
> I will do more research. Checking docker version may be one option,
> and checking whether one option is support by docker may be also one
> option. I will try them later, while waiting if there are some other
> opinions :)
> 
>>>>> I am not sure if this is a testbug, so I did not file it on JBS. In
>>>>> fact, I am not quite sure what kind of issue can be filed on JBS. Is
>>>>> there any guidance document?
>>>> 
>>>> Any/all issues can be filed on JBS. You don't need to pre-classify as a
>>>> testbug, simple create an issue that a test is failing under specific
>>>> conditions. Whomever works on the bug will then determine whether it is
>>>> a testbug or product issue or something else. (We don't seem to have any
>>>> docs on using JBS ...)
>>>> 
>>> 
>>> What if the issue is not a bug or no body cares the issue? The issue
>>> will be open on JBS forever?
>> 
>> Possibly :) But each component team performs regular triage of the bugs
>> that get filed and eventually things will be examined enough to see if
>> they are indeed a bug, and if not they will be closed as not an issue.
>> If a bug but low priority it may eventually get closed as "will not fix"
>> just to keep the open bug count down.
>> 
> 
> I was a little afraid that filing issues that are not bugs or nobody
> cares would increase the workload of others and frustrate myself, so I
> was not sure what kind of issue should be filed. Now I basically
> clear, thanks David.
> 
>> Cheers,
>> David
>> 
>>> Thanks for your explanation, and I filed this issue on JBS:
>>> https://bugs.openjdk.java.net/browse/JDK-8217597
>>> 
>>>> In this case I'm not sure whether we require a docker version that
>>>> supports --cpus, and the test should be skipped otherwise. Though
>>>> ideally this would involve an explicit version check so we don't just
>>>> pass if the docker process fails.
>>>> 
>>>> Thanks,
>>>> David
>>>> 
>>>> 
>>>>> 
>>>>> Cheers,
>>>>> Ao Qi
>>>>> 
>>>>> [1] https://docs.docker.com/config/containers/resource_constraints/#cpu
>>>>>