Question on Shenandoah GarbageCollectorMXBeans

[zgu at redhat.com]

Hi Michael,

I have no idea how this message went under our radar for so long, I
just found out this morning, sorry! 

I filed https://bugs.openjdk.java.net/browse/JDK-8219976, and am
working on the fix.

Thanks,

-Zhengyu

On Thu, 2018-11-08 at 10:54 +0100, Michael Nitschinger wrote:
> Hi,
> 
> I’ve been trying to get GC information through the
> GarbageCollectorMXBean instances and it is working great so far,
> although I have a couple of questions. I couldn’t find any
> documentation on this topic, so sorry if it is written up somewhere.
> 
> I’m adding my NotificationListener to the MXBeans returned by the
> ManagementFactory with shenandoah enabled and:
> 
> when I’m looking at the “cause” of the
> GarbageCollectionNotificationInfo it always says “No GC” which seems
> weird to me (both for the Pauses and the Cycles bean) - even that the
> action contains messages like “end of major GC” or “end of minor GC".
> In terms of “action”, Shenandoah Pauses always seems to return “end
> of major GC” while Shenandoah Cycles returns “end of minor GC”, but
> is that really accurate? There seems to be only one “shenandoah”
> memory pool and while the Cycles info has memory usage attached to
> it, the Pauses one has no memory information whatsoever (all values
> are zeroed out).
> 
> I’m running on 1.8.0_181-b15 that ships with fedora and the only JVM
> flag that I set was -XX:+UseShenandoahGC.
> 
> Happy to provide more information if required,
> Thanks,
> Michael 
>