RFR: 8198668: MemoryPoolMBean/isUsageThresholdExceeded/isexceeded001/TestDescription.java still failing [v2]

Kevin Walls kevinw at openjdk.org
Thu Jun 30 20:21:48 UTC 2022


On Tue, 28 Jun 2022 11:43:42 GMT, Kevin Walls <kevinw at openjdk.org> wrote:

>> Test has been problemlisted for a long time due to intermittent failures.
>> 
>> This is a difficult test as it tries to monitor usage thresholds on Memory Pools which are outside its control.
>> Not just Java heap pools, where the allocation it makes may or may not affect a particuclar pool, but non-heap pools such as CodeHeap and Metadata, where other activity in the VM can affect their usage and surprise the test.
>> 
>> The test iterates JMX memory pools where thresholds are supported, sets a threshold one byte higher than current usage, and makes an allocation.  This only makes sense on Java heap pools.  It is tempting to skip non-heap pools, but this test can still give a sanity test about threshold behaviour.  That is actually its main purpose, as the allocation is unlikely to affect the pool being tested.
>> 
>> With the changes here, I'm seeing the test and all its variations pass reliably, i.e. 50 iterations in each tested platform.
>> 
>> Skip testing a non-heap memory pool, e.g. CodeHeap, if it is hitting the threshold while we test, because that means it is changing outside our control.  Also re-test isExceeded on failure, as fetching the usage and isExceeded is a race.
>> 
>> Logging of more pool stats to better understand failures.
>
> Kevin Walls has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Show log output

Thanks Leonid!

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PR: https://git.openjdk.org/jdk/pull/9309


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