G1gc compaction algorithm

[Martin Makundi]

>
>
> >
> >         Comments to your questions inlined.
> >         Thanks,
> >         Jenny
> >         On 7/23/2014 8:01 AM, Martin Makundi wrote:
> >
> >         > 1. Log says "recent GC overhead higher than threshold after
> >         > GC, recent GC overhead: 13.94 %, threshold: 10.00 %" what is
> >         > that 10% threshold how can it be changed and what will it
> >         > affect?
> >         G1 uses this to decide when to expand the heap.  It means when
> >         the gc pause time is over 10% of the application time, then we
> >         need to expand the heap.
> >
> > Is this adjustable, I did not notice any parameters affecting this 10%
> > threshold?
>
> GC overhead = 100.0 * (1.0 / (1.0 + GCTimeRatio))
>
> This somewhat complicated formula is due to backwards compatibility.
>

Is this something that I can tune also for g1gc, e.g., example, with -XX:
*GCTimeRatio*=9 default?

What will it affect and how does it relate to MaxGCPauseMillis, or are they
related at all to each other?

**
Martin


>
> Thomas
>
>
>
>
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