Yonik, I am really excited about the Json faceting module. I find it really interesting. Is there any pros/cons in using them, or it's definitely the "approach of the future" ? I saw your benchmarks and seems impressive.
I have not read all the topic in details, just briefly, but is Json faceting using different faceting algorithms from the standard ones ? ( Enum and fc) I can not find the algorithm parameter to be passed in the Json facets. Are they using a complete different approach ? Is the algorithm used expressed anywhere ? This could give very good insights on when to use them. Cheers 2015-09-24 14:58 GMT+01:00 Yonik Seeley <ysee...@gmail.com>: > On Mon, Sep 21, 2015 at 8:09 AM, Uwe Reh <r...@hebis.uni-frankfurt.de> > wrote: > > our bibliographic index (~20M entries) runs fine with Solr 4.10.3 > > With Solr 5.3 faceted searching is constantly incredibly slow (~ 20 > seconds) > [...] > > > > The 'fieldValueCache' seems to be unused (no inserts nor lookups) in Solr > > 5.3. In Solr 4.10 the 'fieldValueCache' is in heavy use with a > > cumulative_hitratio of 1. > > > Indeed. Use of the fieldValueCache (UnInvertedField) was secretly > removed as part of LUCENE-5666, causing these performance regressions. > > This code had been evolved over years to be very fast for specific use > cases. No one facet algorithm is going to be optimal for everyone, so > it's important we have multiple. But use of the UnInvertedField was > removed without any notification or discussion whatsoever (and > obviously no benchmarking), and was only discovered later by Solr devs > in SOLR-7190 that it was essentially dead code. > > > When I brought back my "JSON Facet API" work to Solr (which was based > on 4.10.x) it came with a heavily modified version of UnInvertedField > that is available via the JSON Facet API. It might currently work > better for your usecase. > > On your normal (non-docValues) index, you can try something like the > following to see what the performance would be: > > $ curl http://yxz/solr/hebis/query -d 'q=darwin& > json.facet={ > authors : { type:terms, field:author_facet, limit:30 }, > material_access : { type:terms, field:material_access, limit:30 }, > material_brief : { type:terms, field:material_brief, limit:30 }, > rvk : { type:terms, field:rvk_facet, limit:30 }, > lang : { type:terms, field:language, limit:30 }, > dept : { type:terms, field:department_3, limit:30 } > }' > > There were other changes in LUCENE-5666 that will probably slow down > faceting on the single valued fields as well (so this may still be a > little slower than 4.10.x), but hopefully it would be more > competitive. > > -Yonik > -- -------------------------- Benedetti Alessandro Visiting card - http://about.me/alessandro_benedetti Blog - http://alexbenedetti.blogspot.co.uk "Tyger, tyger burning bright In the forests of the night, What immortal hand or eye Could frame thy fearful symmetry?" William Blake - Songs of Experience -1794 England
