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From Victoria Kagansky <victoria.kagan...@gmail.com>
Subject Re: Multi-core memory problem
Date Thu, 08 Apr 2010 07:51:14 GMT
The queries do require sorting (on int) and faceting. They should fetch
first 200 docs.
The current problematic core has 10 entries in fieldCache and  5 entries in
filterCache. The other caches are empty. Is there any way to know how much
memory specific cache takes?

The problem is that one core behaves well, while the other one throws
OutOfMemory exceptions right from the restart. This behavior is consistent
if I switch the order of the cores initialization. It feels like there the
core initialized second has no memory resources assigned.



On Thu, Apr 8, 2010 at 4:26 AM, Lance Norskog <goksron@gmail.com> wrote:

> Sorting takes memory. What data types are the fields sorted on? If
> they're strings, that could be a space-eater. If they are ints or
> dates, not a problem.
>
> Do the queries pull all of the documents found? Or do they just fetch
> the, for example, first 10 documents?
>
> What are the cache statistics like? Can they be shrunk? The stats are
> shown the Statistics page off of the main solr/admin page.
>
> Facets come from something called the Lucene Field Cache, which is not
> controlled out of Solr. It has no eviction policy. When you do a facet
> request, the memory used to load up the facets for a particular field
> will not be evicted. So if you have lots and lots of facets, this
> could be a problem.
>
> On Wed, Apr 7, 2010 at 3:45 PM, Victoria Kagansky
> <victoria.kagansky@gmail.com> wrote:
> >  Hi,
> > We are using Solr 1.4 running 2 cores each containing ~90M documents.
> Each
> > core index size on the disk is ~ 120 G.
> > The machine is a 64-bit quad-core 64G RAM running Windows Server 2008.
> > Max heap size is set to 9G for the Tomcat process. Default caches are
> used.
> >
> > Our queries are complex and involve  8 facet fields (3 of them are
> boolean)
> > and sorting on up 2 fields in addition to Solr score.
> > I noticed a new behavior that didn't happened before: the first core
> being
> > queried after startup answers all the queries, even the ones bringing ten
> > millions of the documents, while the other core (that was queried the
> > second) causes OutOfMemory exceptions for any query, even the "smallest"
> > one. The heap is shown as not fully used 6-5 G out of 9. This is very
> > strange because till recently both cores were working well, handling the
> > heaviest queries, while the heap usage was on 8 G.
> >
> > Any ideas?
> >
> > Thanks
> >
>
>
>
> --
> Lance Norskog
> goksron@gmail.com
>

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