Hi Dmitry, No, we were not able to solve the sorting/re-ranking issue. In the end we migrated the custom sorting formula to using the 'q' param instead of 'sort' to get back the results sorted by score as expected.
That mostly solved our issues with inconsistent Solr scores. Maybe sorting and re-ranking are conflicting concepts. Hope this helps. On Fri, Aug 28, 2020 at 4:28 PM Jörn Franke <jornfra...@gmail.com> wrote: > Maybe this can help you? > > https://lucene.apache.org/solr/guide/7_5/distributed-requests.html#configuring-statscache-distributed-idf > > On Mon, May 11, 2020 at 9:24 AM Spyros Kapnissis <ska...@gmail.com> wrote: > > > HI all, > > > > On our current master/slave setup (no cloud), we use a a custom sorting > > function to get the first pass results (using the sort param), and then > we > > use LTR for re-ranking. This works fine, i.e. re-ranking is applied on > the > > topN, after sorting has completed and the order is correct. > > > > However, as we are migrating on SolrCloud (version 7.3.1) with multiple > > shards, this does not seem to work as expected. To my understanding, Solr > > collects the reranked results from the shards back on a single node to > > merge them, and then tries to re-apply sorting. > > > > We would expect the results to at least follow the sorting formula, even > if > > this is not what we want. But this still not even the case, as the > > combination of the two (sorting + reranking) results in erratic ordering. > > > > Example result, where $sort_score is the sorting formula output, and > score > > is the LTR re-ranked output: > > > > {"id": "152", > > "$sort_score": 17.38543, > > "score": 0.22140852 > > }, > > {"id": "2016", > > "$sort_score": 14.612957, > > "score": 0.19214153 > > }, > > { "id": "1523", > > "$sort_score": 14.4093275, > > "score": 0.26738763 > > }, > > { "id": "6704", > > "$sort_score": 13.956842, > > "score": 0.17357588 > > }, > > { "id": "6512", > > "$sort_score": 14.43907, > > "score": 0.11575622 > > }, > > > > We also tried with other simple re-rank queries apart from LTR, and the > > issue persisted. > > > > Could someone please help troubleshoot? Ideally, we would want to have > the > > re-rank results merged on the single node, and not re-apply sorting. > > > > Thank you! > > >
