RFR [XS]: 8229370: make jdk/jfr/event/runtime/TestNetworkUtilizationEvent.java more stable
matthias.baesken at sap.com
Fri Sep 27 10:56:58 UTC 2019
Hi David / Mikhailo , I adjusted the test a bit more , and also added (+enabled) UL-based jfr,event tracing in src/hotspot/share/jfr/periodic/jfrNetworkUtilization.cpp
to better see the recorded event information .
The current revision
sends DatagramPackets to all InetAddresses of all network interfaces of the machine .
I observed that on our "problematic" machine where the test fails we still need a little delay to see the read / write counters (fetched by os_perf and then used in the JFR)
increase on the machine ( that’s why I wait a bit before every send operation).
Could you please check 8229370.3 also in your infrastructure where you noticed sporadic failures in jdk/jfr/event/runtime/TestNetworkUtilizationEvent.java and tell me
about the results ?
Best regards, Matthias
> Subject: Re: RFR [XS]: 8229370: make
> jdk/jfr/event/runtime/TestNetworkUtilizationEvent.java more stable
> 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.
> > 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
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