RFR [XS]: 8229370: make jdk/jfr/event/runtime/TestNetworkUtilizationEvent.java more stable

[David Holmes]

Hi Matthias,

On 24/09/2019 12:23 am, Baesken, Matthias wrote:
> Hi David /  Mikhailo , I was busy with other tasks  but today  got back to  8229370 .
> 
> I noticed that in the meantime,   the test was excluded  with
> 
> https://bugs.openjdk.java.net/browse/JDK-8230115
> 
> "Problemlist JFR TestNetworkUtilization test"
> 
> 
> Do you think we still should  rely  on the OS counters , and expect to get  2+ network interfaces,  or  keep  the test excluded (or just relax  the check and  check for 1+  network interfaces on Linux)  ?

Exclusion is just a temporary measure to clean up the testing results, 
so this still needs to be fixed. I have nothing further to add from my 
comments in the bug:

 > So it should be as simple as changing 10.0.0.0:12345 into something
 > guaranteed to work?
 >
 > I think this needs to be looked at by the JFR folk and net-dev folk to
 > come up with a valid testing scenario.

It's not the number of interfaces that is the issue, it is generating 
traffic on the real interface.

Thanks,
David

> 
> Best regards, Matthias
> 
> 
> 
>>
>> On 29/08/2019 12:24 am, Baesken, Matthias wrote:
>>> Hi David ,   I could  add some  optional  UL logging  to see   what happens.
>>
>> I just want to see more visibility at the test level to ensure it is
>> finding the interfaces and addresses I would expect it to find.
>>
>> David
>>
>>> Maybe the  OS counters   that are fetched by   os_perf    are not that
>> reliable on some  kernels .
>>>
>>>
>>> Best regards, Matthias
>>>
>