Erratic(?) CMS behaviour after 5d
Bernd Eckenfels
bernd-2012 at eckenfels.net
Sat Sep 29 14:03:12 PDT 2012
Hello,
> You're seeing concurrent mode failures (see attached graph)
The graph is cool, how do you create it. But I am not sure about the
concurrent Mode failure theory, there is no such message in the log, the
old heap is nearly empty and no FullGC are happening.
> i'd recommend trying these flags:
> -XX:CMSInitiatingOccupancyFraction=60
Yes, currently it is much smaller by auto tuning (I guess I will use 10%
and shrink the heap. AFAIK it needs to be combined with
-XX:+UseCMSInitiatingOccupancyOnly?
> It's also possible you are running out of old gen space,
> try increasing your old gen size as well.
Do you know if it is visible in jstat -gccause if Perm is the reason? According
to jstat -heap it was only 75% filled, but I also treat it as a likely
candidate.
> > concurrent mark-sweep generation:
> > capacity = 25769803776 (24576.0MB)
> > used = 1704634416 (1625.6660614013672MB)
> > free = 24065169360 (22950.333938598633MB)
> > 6.614852137863636% used
> > Perm Generation:
> > capacity = 314572800 (300.0MB)
> > used = 238131048 (227.0994644165039MB)
> > free = 76441752 (72.9005355834961MB)
> > 75.69982147216797% used
Greetings
Bernd
PS: lets discuss that in -use list.
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