Share the Term -> TermInfo cache across threads -----------------------------------------------
Key: LUCENE-2075 URL: https://issues.apache.org/jira/browse/LUCENE-2075 Project: Lucene - Java Issue Type: Improvement Components: Index Reporter: Michael McCandless Priority: Minor Fix For: 3.1 Right now each thread creates its own (thread private) SimpleLRUCache, holding up to 1024 terms. This is rather wasteful, since if there are a high number of threads that come through Lucene, you're multiplying the RAM usage. You're also cutting way back on likelihood of a cache hit (except the known multiple times we lookup a term within-query, which uses one thread). In NRT search we open new SegmentReaders (on tiny segments) often which each thread must then spend CPU/RAM creating & populating. Now that we are on 1.5 we can use java.util.concurrent.*, eg ConcurrentHashMap. One simple approach could be a double-barrel LRU cache, using 2 maps (primary, secondary). You check the cache by first checking primary; if that's a miss, you check secondary and if you get a hit you promote it to primary. Once primary is full you clear secondary and swap them. Or... any other suggested approach? -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online. --------------------------------------------------------------------- To unsubscribe, e-mail: java-dev-unsubscr...@lucene.apache.org For additional commands, e-mail: java-dev-h...@lucene.apache.org