RFR: 8264524: jdk/internal/platform/docker/TestDockerMemoryMetrics.java fails due to OOM killed

[Jie Fu]

On Wed, 31 Mar 2021 17:14:32 GMT, Severin Gehwolf <sgehwolf at openjdk.org> wrote:

>> Hi all,
>> 
>> jdk/internal/platform/docker/TestDockerMemoryMetrics.java fails on some of our testing platforms.
>> This is because testMemoryFailCount [1] fails due to OOM killed.
>> This test fails to avoid OOM killed [2] if memory.failcnt is always 0.
>> 
>> The fix will print "Not OOM killed" if OOM killed doesn't happen.
>> And also fix another bug if the test get returned here [3].
>> 
>> Testing: 
>>   - jdk/internal/platform/docker/ hotspot/jtreg/containers on Linux/x64
>> 
>> Thanks.
>> Best regards,
>> Jie
>> 
>> [1] https://github.com/openjdk/jdk/blob/master/test/jdk/jdk/internal/platform/docker/TestDockerMemoryMetrics.java#L80
>> [2] https://github.com/openjdk/jdk/blob/master/test/jdk/jdk/internal/platform/docker/MetricsMemoryTester.java#L87
>> [3] https://github.com/openjdk/jdk/blob/master/test/jdk/jdk/internal/platform/docker/MetricsMemoryTester.java#L96
>
> test/jdk/jdk/internal/platform/docker/TestDockerMemoryMetrics.java line 120:
> 
>> 118:                 oa.shouldHaveExitValue(0).shouldContain("TEST PASSED!!!");
>> 119:             }
>> 120:         }
> 
> Consider a broken implementation of `Metrics.systemMetrics().getMemoryFailCount()`. Wouldn't the test now (falsely) pass?
> 
> What is the actual test output on those systems where the test fails? There should be a docker log file. Does it enter line 91?

Hi @jerboaa ,

After more thinking, I think the reason why memory.failcnt is always 0 is that there is no swap space on the host machine.
So the testMemoryFailCount should be skipped in that case.

But is there any API which can be used to get the swap space size of the host machine?

Thanks.

-------------

PR: https://git.openjdk.java.net/jdk/pull/3286