ZGC Unable to reclaim memory for long time
per.liden at oracle.com
Thu Nov 7 07:25:10 UTC 2019
On 11/7/19 2:28 AM, Sundara Mohan M wrote:
> Unfortunately i don't have that stats. I was running application with
> this option for gc
> log -Xlog:gc,gc+init,gc+start,gc+phases,gc+heap,gc+cpu,gc+reloc,gc+ref,gc+marking,gc+metaspace=info.
> Will see if i can get that issue reproducible and get that data for you.
Ok, thanks. I'd recommend using -Xlog:gc*, that way you catch pretty
much all you need to tell what's going on, without being super verbose.
> On Wed, Nov 6, 2019 at 3:08 PM Per Liden <per.liden at oracle.com
> <mailto:per.liden at oracle.com>> wrote:
> On 11/6/19 10:04 PM, Sundara Mohan M wrote:
> > But on the other hand with ZGC my throughput increased from
> > *(ParallelGC)97%* to*(ZGC)99.7% *and my STW pauses have never
> crossed 20ms.
> Could you please paste the last printout of the "Garbage Collection
> Statistics" table? If you have pauses close to 20ms, it would be
> interesting to see where that time is spent. I would assume it's
> accounted to "Subphase: Pause Roots Threads", but seeing the whole
> would tell the me more.
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