On Wed, Dec 16, 2015 at 4:57 AM, Vincenzo D'Amore <v.dam...@gmail.com> wrote: > Hi all, > > given that solr 5.4 is finally released, is this what's more stable and > efficient version of solrcloud ? > > I have a website which receives many search requests. It serve normally > about 2000 concurrent requests, but sometime there are peak from 4000 to > 10000 requests in few seconds. > > On January I'll have a chance to upgrade my old SolrCloud 4.8.1 cluster to > a new brand version, but following this thread I read about the problems > that can occur upgrading to latest version. > > I have seen that issue SOLR-7730 "speed-up faceting on doc values fields" > is fixed in 5.4. > > I'm using standard faceting without docValues. Should I add docValues in > order to benefit of such fix?
You'll have to try it I think... DocValues have a lot of advantages (much less heap consumption, and much smaller overhead when opening a new searcher), but they can often be slower as well. Comparing 4x to 5x non-docvalues, top-level field caches were removed by lucene, and while that benefits certain things like NRT (opening a new searcher very often), it will hurt performance for other configurations. The JSON Facet API currently allows you to pick your strategy via the "method" param for multi-valued string fields without docvalues: "uif" (UninvertedField) gets you the top-level strategy from Solr 4, while "dv" (DocValues built on-the-fly) gets you the NRT-friendly "per-segment" strategy. -Yonik
