I'm not understanding where the inconsistency comes into play. The re-ranking occurs on the shards. The aggregator node will be sent some docs that have been re-scored and others that are not. But the sorting should be the same as someone pages through the result set.
Joel Bernstein http://joelsolr.blogspot.com/ On Fri, Sep 9, 2016 at 9:28 AM, Alessandro Benedetti <abenede...@apache.org> wrote: > Hi guys, > was just experimenting some reranker with really low number of rerank docs > ( 10= pageSize) . > Let's focus on the distributed enviroment and the manual sharding > approach. > > Currently what happens is that the reranking task is delivered by the > shards, they rescore the docs and then send them back to the aggregator > node. > > If you want to rerank only few docs ( leaving the others with the original > score following), this can be done in a single Solr instance ( the howmany > logic manages that in the reranker) . > > What happens when you move to a distributed environment ? > The aggregator will aggregate both rescored and original scored documents, > making the final ranking inconsistent. > In the other hand if we make the rarankingDocs threshold dynamic ( to adapt > to start+rows) we can incur in the very annoying issue of having a document > sliding through the pages ( visible in the first page , then appearing > again in the third ect ect). > > Any thought ? > > Cheers > > -- > -------------------------- > > Benedetti Alessandro > Visiting card : http://about.me/alessandro_benedetti > > "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 >
