G1gc compaction algorithm

[Yu Zhang]

Martin,

The ScanRS for mixed gc is extremely long, 1000-9000ms.  Because it is 
over pause time goal, minimum old regions can be added to CSet.  So 
mixed gc is not keeping up.

Can do a run keeping 16m region size,  no G1PrintRegionLivenessInfo, no 
PrintHeapAtGC.  But -XX:+G1SummarizeRSetStats 
-XX:G1SummarizeRSetStatsPeriod=10

This should tell us more about RSet information.

While the UpdateRS is not as bad as ScanRS, we can try to push it to the 
concurrent threads.  Can you add -XX:G1RSetUpdatingPauseTimePercent=5.  
I am hoping this brings the UpdateRS down to 50ms.

Thanks,
Jenny

On 7/28/2014 8:27 PM, Martin Makundi wrote:
> Hi!
>
> We suffered a couple of Full GC's using regionsize 5M (it seems to be 
> exact looking at logged actual parameters) and we tried the 16M option 
> and this resulted in more severe Full GC behavior.
>
> Here is the promised log for 16 M setting: 
> http://81.22.250.165/log/gc-16m.log
>
> We switch back to 5M hoping it will behave more nicely.
>
> **
> Martin