RFR (S) 8223441: HeapMonitorStatArrayCorrectnessTest fails due to sampling determinism

[Jean Christophe Beyler]

Hi all,

Due to this failing pretty heavily a test it seems; is there any way I
could get a second reviewer so I can hopefully calm the test bug demons?

Thanks!
Jc

On Wed, May 8, 2019 at 7:49 AM Jean Christophe Beyler <jcbeyler at google.com>
wrote:

> Hi Serguei,
>
> Done & Done; I think 10 instead of 5 will be ok. It only continues running
> if the sampling interval average has not converged so it should only
> lengthen degenerate cases.
>
> Thanks for the review,
> Jc
>
> On Wed, May 8, 2019 at 2:00 AM serguei.spitsyn at oracle.com <
> serguei.spitsyn at oracle.com> wrote:
>
>> Hi Jc,
>>
>> A couple of minor comments.
>>
>>   37   private static final int maxCount = 5;
>>
>>   Constant names are better to start from a capital letter.
>>   Also, I'd suggest 10 instead of 5 to make it more reliable.
>>   But it depend on how much it potentially can make the test to run
>> slower.
>>
>>   94       // If we failed maxCount times, through the exception.
>>
>>   A typo: replace "through" with "throw".
>>
>>
>> Otherwise, I'm Okay with this fix.
>> No need for another webrev.
>>
>>
>> Thanks,
>> Serguei
>>
>>
>> On 5/7/19 19:47, Jean Christophe Beyler wrote:
>>
>> Hi all,
>>
>> Could I get a review for this test fix:
>>
>> Webrev: http://cr.openjdk.java.net/~jcbeyler/8223441/webrev.00/
>> Bug: https://bugs.openjdk.java.net/browse/JDK-8223441
>>
>> Backstory is:
>> When I fixed https://bugs.openjdk.java.net/browse/JDK-8215113, I fixed
>> this failing test in the "actually make the error calculation correct". But
>> it turns out the test itself failed 7 out of 10 times and when we tested
>> it, we were apparently "lucky".
>>
>> This fix makes the test pass 5k times so I am hopeful it will not show up
>> again.
>>
>> Extra notes:
>>    - I fixed this by adding a loop that says: if we have not converged
>> yet, try again at max 5 times; generally we don't converge if the sampling
>> intervals chosen at the start just have pushed us far enough from the
>> average we expect that it takes more samples to get us back on track
>>
>> Thanks,
>> Jc
>>
>> Ps: FWIW, I'm going to look at the flakyness of the rest of the suite and
>> see if anything pops up to reduce the test bug noise of this suite
>>
>>
>>
>
> --
>
> Thanks,
> Jc
>


-- 

Thanks,
Jc
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