Histograms in jVisualVM-VisualGC plugin "not supported"

[Michael Finocchiaro]

Thanks Krystal,
You are totally right - I needed to explicitly switch using
-XX:+UseParNewGC to see the Histograms again.
Thanks :)
BTW, does G1 use a similar technique or is there a new parallel algorithm
for scavange on new for G1?
Cheers,
Fino

Michael Finocchiaro
michael.finocchiaro at gmail.com
Mobile Telephone: +33 6 46 59 36 62
MSN: le_fino at hotmail.com
Twitter: le_fino
Skype: michael.finocchiaro
Blog: http://mfinocchiaro.wordpress.com
LinkedIn: http://fr.linkedin.com/in/mfinocchiaro


On Thu, Oct 4, 2012 at 6:56 PM, Krystal Mok <rednaxelafx at gmail.com> wrote:

> Hi Fino,
>
> It's possible that you're using a different GC strategy in your Java7
> environment from your Java6 one.
> The VisualGC plugin for VisualVM doesn't support displaying histogram
> information for ParallelGC; it works with other GCs in HotSpot, e.g.
> DefNew/ParNew/G1. This hasn't changed from JDK6 to JDK7.
>
> Please take a look at what GC you're using in the two environments you're
> comparing.
>
> - Kris
>
> On Thu, Oct 4, 2012 at 3:50 AM, Michael Finocchiaro <
> michael.finocchiaro at gmail.com> wrote:
>
>> Perhaps the wrong forum for this question - if so please redirect me.
>> I upgraded my Java to Java7 but with the same parameters for starting my
>> Tomcat, I am no longer able to see the histograms in the VisualGC plugin to
>> jVisualVM that were so useful for checking the tuning of SurvivorRatio back
>> when I ran on Java6. Is this a known limitation on Java7 or did I miss a
>> command-line parameter somewhere?
>> Cheers,
>> Fino
>>
>> Michael Finocchiaro
>> michael.finocchiaro at gmail.com
>> Mobile Telephone: +33 6 46 59 36 62
>> MSN: le_fino at hotmail.com
>> Twitter: le_fino
>> Skype: michael.finocchiaro
>> Blog: http://mfinocchiaro.wordpress.com
>> LinkedIn: http://fr.linkedin.com/in/mfinocchiaro
>>
>> _______________________________________________
>> hotspot-gc-use mailing list
>> hotspot-gc-use at openjdk.java.net
>> http://mail.openjdk.java.net/mailman/listinfo/hotspot-gc-use
>>
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mail.openjdk.java.net/pipermail/hotspot-gc-use/attachments/20121005/690f8a73/attachment.html