lucene-solr-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Zheng Lin Edwin Yeo <edwinye...@gmail.com>
Subject Re: Memory Usage increases by a lot during and after optimization .
Date Fri, 08 Jan 2016 02:09:29 GMT
Hi Shawn,

I am using Java Version 8 Update 45 (build 1.8.0_45-b15). It is a 64-bit
Java.

Thank you.

Regards,
Edwin


On 8 January 2016 at 00:15, Shawn Heisey <apache@elyograg.org> wrote:

> On 1/7/2016 12:53 AM, Zheng Lin Edwin Yeo wrote:
> >> Subtracting SHR from RES (or in your case, Shareable from Working)
> >> reveals the actual memory being used, and I believe you can see this
> >> actual number in the Private column, which is approximately the
> >> difference between Working and Shareable.  If I'm right, this means that
> >> the actual memory usage is almost 14GB lower than Windows is reporting.
> > Does this means that sometimes when I see the high memory usage (can be
> up
> > to 100%), it is just a memory reporting error by Windows, but Solr is
> > working exactly as it should?
>
> I believe so, yes.  It should be completely impossible for Java to
> allocate more memory than you ask it to ... and I believe that Java is
> acting correctly in this regard, but the reporting is wrong.
>
> I do not know whether anything can be done about the reporting problem.
> The fact that it happens with Java on two different operating systems
> (that I know of) suggests that the problem is in Java itself.
>
> I suspect that it is related to the fact that the index files are
> accessed via MMap, and part of that virtual memory is misreported as
> shared memory.  I am subscribed to the hotspot mailing list for
> openjdk.  I don't know whether the message will be on-topic for the
> list, but I will ask about it there.  For this message I will need to
> know the precise version of Java you are using, including whether it's
> 32 or 64-bit.
>
> Thanks,
> Shawn
>
>

Mime
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message