In this thread about performance on concurrent search requests, Otis said: http://lucene.472066.n3.nabble.com/how-to-improve-concurrent-request-performance-and-stress-testing-td496411.html
/Imagine this type of code: synchronized (someGlobalObject) { // search } What happens when 100 threads his this spot? The first one to get there gets in and runs the search and 99 of them wait. What happens if that "// search" also involves expensive operations, lots of IO, warming up, cache population, etc? Those 99 threads will have to wait a while.... :) That's why it is recommended to warm up the searcher ahead of time before exposing it to real requests. However, even if you warm things up, that sync block will remain there, and at some point this will become a bottleneck. What that point is depends on the hardware, index size, query complexity and rat, even JVM. Otis / I'm wondering if this synchronized is still an issue in Solr 4.x? Is it because how Solr deals with the index searcher or is it because how it is implemented in Lucene? -- View this message in context: http://lucene.472066.n3.nabble.com/performance-on-concurrent-search-request-tp4053182.html Sent from the Solr - User mailing list archive at Nabble.com.