Thanks Shawn for your suggestions. Best, Modassar
On Wed, Oct 12, 2016 at 11:44 AM, Shawn Heisey <apa...@elyograg.org> wrote: > On 10/11/2016 11:46 PM, Modassar Ather wrote: > > We see queries executing in less than a second and taking minutes to > > execute as well. We need to predict the approximate time a query might > > take to execute. Need your help in finding the factors to be > > considered and calculating an approximate execution time. > > If a query or filter query has been cached successfully by Solr, then > running it again while on the same searcher will happen very quickly. > > I think you can look at the number of fields in the query and the number > of terms being searched in each of those fields as a general guide for > query complexity. Wildcard queries can expand to a large number of > terms, so those can be quite slow. > > Deep paging (setting the start parameter to a high number) can make > queries slow, particularly on multi-shard indexes. > > Using complex queries as filters (fq parameter) will tend to run slower > than the same thing in the q parameter, at least the first time the > filter is executed on an index searcher. Once a given filter query is > in the filterCache, it typically will execute VERY quickly. Be aware > that using NOW in date queries without rounding will change the query on > every execution, so it cannot be cached. > > Complex features like faceting, grouping, and the stats component will > tend to take longer with fields that have a very large number of terms, > and might also take longer with queries that have many matches. > > Other people might have a better idea of what kinds of queries are slow, > but hopefully this is a decent guide. > > If you truly cannot see any sort of common qualities in your slow > queries, then you may be running into a situation where you don't have > enough memory for your index to be effectively cached. This situation > can cause a query that would normally be fast to be very slow, if the > index data the query needs has been pushed out of the operating system > disk cache by other queries. Information about effective disk caching > is discussed here: > > https://wiki.apache.org/solr/SolrPerformanceProblems > > Thanks, > Shawn > >
