Hi guys,
I have a Solr 4.10.4 instance with a RequestHandler that has a
re-ranking query configured like this:
<lst name="defaults">
<str name="defType">dismax</str>
...
<str name="rqq">{!boost b=someFunction() v=$q}</str>
<str name="rq">{!rerank reRankQuery=$rqq reRankDocs=60
reRankWeight=1.2}</str>
<str name="sort">score desc</str>
</lst>
Everything is working until the client sends a sort params that doesn't
include the score field. So if for example the request contains
"sort=price asc" then a NullPointerException is thrown:
/
//09:46:08,548 ERROR [org.apache.solr.core.SolrCore]
java.lang.NullPointerException//
//[INFO] [talledLocalContainer] at
org.apache.lucene.search.TopFieldCollector$OneComparatorScoringMaxScoreCollector.collect(TopFieldCollector.java:291)//
//[INFO] [talledLocalContainer] at
org.apache.solr.search.ReRankQParserPlugin$ReRankCollector.collect(ReRankQParserPlugin.java:263)//
//[INFO] [talledLocalContainer] at
org.apache.solr.search.SolrIndexSearcher.sortDocSet(SolrIndexSearcher.java:1999)//
//[INFO] [talledLocalContainer] at
org.apache.solr.search.SolrIndexSearcher.getDocListC(SolrIndexSearcher.java:1423)//
//[INFO] [talledLocalContainer] at
org.apache.solr.search.SolrIndexSearcher.search(SolrIndexSearcher.java:514)//
//[INFO] [talledLocalContainer] at
org.apache.solr.handler.component.QueryComponent.process(QueryComponent.java:484)//
//[INFO] [talledLocalContainer] at
org.apache.solr.handler.component.SearchHandler.handleRequestBody(SearchHandler.java:218)//
//[INFO] [talledLocalContainer] at
org.apache.solr.handler.RequestHandlerBase.handleRequest(RequestHandlerBase.java:135)
/The only way to avoid this exception is to _explicitly_ add th/e "score
desc" /value to the incoming field (i.e. sort=price asc, score desc). In
this way I get no exception. I said "explicitly" because adding an
"appends" section in my handler
<lst name="appends">
<str name="sort">score desc</str>
</lst>
Even I don't know if that could solve my problem, in practice it is
completely ignoring (i.e. I'm still getting the NPE above).
However, when I explicitly add "sort=price asc, score desc", as
consequence of the re-ranking, the top 60 results, although I said to
Solr "order by price", are still shuffled and that's not what I want.
On top of that I have two questions:
* Any idea about the exception above?
* How can I disable the re-ranking query in case the order is not by
score?
About the second question, I'm thinking to the following solutions, but
I'm not sure if there's a better way to do that.
1. Create another request handler, which is basically a clone of the
handler above but without the re-ranking stuff
2. Use local params for the reRankDocs...
<lst name="defaults">
<str name="defType">dismax</str>
...
<str name="rqq">{!boost b=someFunction() v=$q}</str>
<str name="rq">{!rerank reRankQuery=$rqq reRankDocs=*$rrd*
reRankWeight=1.2}</str>
*<str name="rrd">60</str>*
<str name="sort">score desc</str>
</lst>
...and have (in case of sorting by something different from the score)
the client sending an additional params "rdd=0". This is working but I
still need to explicitly declare "sort=price asc, score desc"
Any thoughts?
Best,
Andrea
