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From Apache Wiki <wikidi...@apache.org>
Subject [Solr Wiki] Trivial Update of "ShawnHeisey" by ShawnHeisey
Date Wed, 31 Dec 2014 00:13:16 GMT
Dear Wiki user,

You have subscribed to a wiki page or wiki category on "Solr Wiki" for change notification.

The "ShawnHeisey" page has been changed by ShawnHeisey:
https://wiki.apache.org/solr/ShawnHeisey?action=diff&rev1=16&rev2=17

Comment:
small change to humoungous allocation info.

  
  I will talk about one further G1 tuning parameter, G1HeapRegionSize.  If the Solr index
is large, entries in the [[SolrCaching#filterCache|filterCache]] may be large enough to be
allocated as "humongous allocations" which means that they are larger than 50 percent of a
G1 heap region.  Such objects are better handled in the young generation, but if they are
categorized as humoungous, they will be allocated from the old generation.
  
- In terms of bytes, the size of each filterCache entry can be determined by taking the maxDoc
value from the Solr core and dividing it by 8.  For a 16 million document index, the cache
entries will each be about 2MB in size.  For that index size, you would need to use -XX:G1HeapRegionSize=8m,
so that those large objects are significantly smaller than 50 percent of the region size.
 See "Humongous Allocations" section on this [[http://www.infoq.com/articles/tuning-tips-G1-GC|blog
entry]] for more information.
+ In terms of bytes, the size of each filterCache entry can be determined by taking the maxDoc
value from the Solr core and dividing it by 8.  For a 16 million document index, the cache
entries will each be about 2MB in size.  For that index size, you would need to use -XX:G1HeapRegionSize=8m,
so that those large objects are significantly smaller than 50 percent of the region size,
and therefore are not categorized as humongous.  See "Humongous Allocations" section on this
[[http://www.infoq.com/articles/tuning-tips-G1-GC|blog entry]] for more information.
  
  === CMS (ConcurrentMarkSweep) Collector ===
  

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