Thanks a lot for these answers! Elisabeth
2011/12/4 Erick Erickson <erickerick...@gmail.com> > See below: > > On Thu, Dec 1, 2011 at 10:57 AM, elisabeth benoit > <elisaelisael...@gmail.com> wrote: > > Hello, > > > > If anybody can help, I'd like to confirm a few things about Solr's caches > > configuration. > > > > If I want to calculate cache size in memory relativly to cache size in > > solrconfig.xml > > > > For Document cache > > > > size in memory = size in solrconfig.xml * average size of all fields > > defined in fl parameter ??? > > pretty much. > > > > > For Filter cache > > > > size in memory = size in solrconfig.xml * WHAT (the size of an id) ??? (I > > don't use facet.enum method) > > > > It Depends(tm). Solr tries to do the best thing here, depending upon > how many docs match the filter query. One method puts in a bitset for > each > entry, which is (maxDocs/8) bytes. maxDocs is reported on the admin/stats > page. > > If the filter cache only hits a few documents, the size is smaller than > that. > > You can think of this cache as a map where the key is the > filter query (which is how they're re-used and how autowarm > works) and the value for each key is the bitset or list. The > size of the map is bounded by the size in solrconfig.xml. > > > For Query result cache > > > > size in memory = size in solrconfig.xml * the size of an id ??? > > > Pretty much. This is the maximum size, but each entry is > the query plus a list of IDs that's up to <queryResultWindowSize> > long. This cache is, by and large, the least of your worries. > > > > > > I would also like to know relation between solr's caches sizes and JVM > max > > size? > > Don't quite know what you're asking for here. There's nothing automatic > that's sensitive to whether the JVM memory limits are about to be exceeded. > If the caches get too big, OOMs happen. > > > > > If anyone has an answer or a link for further reading to suggest, it > would > > be greatly appreciated. > > > There's some information here: http://wiki.apache.org/solr/SolrCaching, > but > it often comes down to "try your app and monitor".... > > Here's a work-in-progress that Grant is working on, be aware that it's > for trunk, not 3x. > http://java.dzone.com/news/estimating-memory-and-storage > > > Best > Erick > > > Thanks, > > Elisabeth >
