: When I run dismax queries I see there are no lookups in the : queryResultCache. If I remove the field collapsing - lookups happen. I : can't find any mention of this anywhere or think of reason why this should
I'm not very familiar with the grouping code, but i think the crux of what you are seeing is that when you using grouping, queryResultCache isn't used because it can't be. queryResultCache is a mapping of <Query,Filter[],Sort[],Pagination> -> <DocList> but with grouping you don't have a simple DocList any more, so there is nothing that can go in (or come out of) the cache. There are probably oportunities for other things to be cached when grouping is used (using new SolrCaches) but i'm not sure what/how. : disable caching. I've tried playing with the group.cache.percent parameter group.cache.percent is ... something different. I don't remember how exactly it works (mvg: ping?), but it definitely doesn't affect any usage of the queryResultCache. If your main concern is caching entire requests (ie: query options, facets, filters, sort, grouping, etc...) then i would suggest you consider putting an HTTP cache in front of Solr. -Hoss
