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Subject: Re: Memory question
References: <CBD93F87.3B1B%john.nader@cengage.com>
From: Chris Bamford <chris@bammers.net>
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In-Reply-To: <CBD93F87.3B1B%john.nader@cengage.com>
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Date: Mon, 21 May 2012 17:49:43 +0100
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This is a progress update on the issue:

I have tried several things and they all gave improvements. In order of magn=
itude they are

1) Reduced heap space from 6GB to 3GB.
This on it's own has so far been the biggest win as swapping almost complete=
ly stopped after this step.=20

2) Began limiting the number of cached IndexSearchers. This is because previ=
ously with non-mmapped indexes sitting in the heap, I evicted cached items b=
ased on heap size calculations - obviously, this is no longer the way to go.=
 Now i just count them - which involves trial and error, but I have arrived a=
t a magic number which seems to have brought swapping completely under contr=
ol (even under extreme load)

3) Implemented CMS gc behaviour in my JVM which seems to keep the heap prune=
d nicely without affecting throughput.=20
Your link to iCMS John is timely as I want to try that next. Will report my f=
indings -- thanks again.

So far so good - cheers to everyone for your valuable suggestions and insigh=
t.

Chris

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