On Tuesday 01 January 2008 19:38:48 Shailendra Sharma wrote: > > Is there are particular reason why CachingWrapperFilter caches per > > IndexReader > > and not per IndexReader.directory()? If there are multiple > > IndexSearcher/IndexReader instances (and only one Directory) cache will > > be built and held in memory redundantly. I don't see any sense in doing > > so (?). > > It's very simple... when you are talking about cache here you are talking > about "In Memory Cache" and not "Persistent" cache. IndexReader is > something which closely resembles in-memory snapshot of indices, while > directory() refers to persisted indices. With this analogy the caching > solution fits best at IndexReader level. > > Over that, same directory can be opened by multiple processes (not threads)
Hmm? But it will be different instances anyway. And that's all you need to use it a key for a WeakHashMap. Maybe we are talking at cross-purposes... I suggest to use reader.directory() instead of reader as key for the WeakHashMap. This way multiple IndexSearcher/IndexReacher instances would share the cache. > - to complicate the situation these processes can be running on distributed > machines. It would require lot of IPCs and very complicated solution to > provide caching at directory level. > > Regards, > Shailendra > > On Jan 1, 2008 11:56 PM, Grant Ingersoll <[EMAIL PROTECTED]> wrote: > > My guess would be b/c best practice is usually to only have one Reader/ > > Searcher per Directory, but I don't know if that is the real reason. > > Most discussions/testing I have seen indicate a single Reader/Searcher > > performs best. > > > > -Grant > > > > On Jan 1, 2008, at 11:57 AM, Timo Nentwig wrote: > > > Hi! > > > > > > Is there are particular reason why CachingWrapperFilter caches per > > > IndexReader > > > and not per IndexReader.directory()? If there are multiple > > > IndexSearcher/IndexReader instances (and only one Directory) cache > > > will be > > > built and held in memory redundantly. I don't see any sense in doing > > > so (?). > > > > > > Thanks for hints... > > > Timo > > > > > > --------------------------------------------------------------------- > > > To unsubscribe, e-mail: [EMAIL PROTECTED] > > > For additional commands, e-mail: [EMAIL PROTECTED] > > > > -------------------------- > > Grant Ingersoll > > http://lucene.grantingersoll.com > > http://www.lucenebootcamp.com > > > > Lucene Helpful Hints: > > http://wiki.apache.org/lucene-java/BasicsOfPerformance > > http://wiki.apache.org/lucene-java/LuceneFAQ > > > > > > > > > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: [EMAIL PROTECTED] > > For additional commands, e-mail: [EMAIL PROTECTED] --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
