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From Phaneendra N <phaneendran.gi...@gmail.com>
Subject Re: Re: memory cost in forceMerge(1)
Date Tue, 11 Aug 2015 11:00:08 GMT
There could be other applications running on the machine with 24 GB memory?
Which would result in total available memory less than what is required. In
this case there may be disk swap, which would take long time.
In theory, if you run this test on machines with memory 50 GB and 100 GB in
this case. You might see the same result.

-Phani

On Tue, Aug 11, 2015 at 2:51 PM, 丁儒 <bforevdr@126.com> wrote:

>
>
> The index will not change oftenly, so we call forceMerge in the end. Will
> forceMerge(1) cost too much memory? And the final size of the index is
> 15GB. I just want to know why different machine cost different time in
> forceMerge, them have the same cpu and disk, but different size of memory.
> One has 24GB, the other has 48 GB. And i allocate -Xmx15GB for the
> application.
>
>
>
>
>
>
> At 2015-08-11 12:30:38, "Erick Erickson" <erickerickson@gmail.com> wrote:
> >It is generally unnecessary to use forceMerge, that's a legacy from
> >older versions of Lucene/Solr.
> >Especially if the index is constantly changing, forceMerge generally
> >is both expensive and not
> >very useful.
> >
> >These indexes must be huge though if any of them are taking 8 hours.
> >What's the background here?
> >
> >Best,
> >Erick
> >
> >On Mon, Aug 10, 2015 at 6:28 PM, 丁儒 <bforevdr@126.com> wrote:
> >> GreetingsNow, i'm using lucene , the version is 4.10.3. For some
> reason, i called forceMerge(1) in the end,and the final  space of the Index
> Library is 15 GB. . But i found that forceMerge(1) cost a lot of time, and
> on different machines ,the time differs.  Is this caused by the different
> size of memory of the macheines. One has 24GB memory, the other has 48GB
> memory. And the machine with 24 GB memory cost nearly 18 hours in
> forceMerge(1), and the machine with 48 GB memory cost nearly 8 hours in
> forceMerge(1). I guess the forceMerge(1) needs too much memory, so it costs
> more time in less memory machine. Am i right ?
> >>
> >>
> >>     Also, can forceMerge(1)  speed up the search?
> >>
> >>
> >> Thank you
> >> All
> >
> >---------------------------------------------------------------------
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> >
>

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