[SOLR-11164] OriginalScoreFeature causes NullPointerException during feature logging with SolrCloud mode.

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 6.6
• Fix Version/s: 7.1, 8.0
• Component/s: contrib - LTR
• Security Level: Public (Default Security Level. Issues are Public)
• Assignee: Christine Poerschke
• Reporter: Yuki Yano
• Created: 28/Jul/17 03:14
• Updated: 17/Oct/17 11:03
• Resolved: 25/Aug/17 14:52

Description

In FeatureTransfer, OriginalScoreFeature uses original Query instance preserved in LTRScoringQuery for the evaluation.
This query is set in RankQuery#wrap during QueryComponent#process.

With SolrCloud mode, document searches take two steps: finding top-N document ids, and filling documents of found ids.
In this case, FeatureTransformer works in the second step and tries to extract features with LTRScoringQuery built in QueryComponent#prepare.
However, because the second step doesn't call QueryComponent#process, the original query of LTRScoringQuery remains null and this causes NullPointerException while evaluating OriginalScoreFeature.

We can get the original query from ResultContext which is an argument of DocTransformer#setContext, thus this problem can solve by using it if LTRScoringQuery doesn't have correct original query.

Issue Links

• is related to: SOLR-11180 OriginalScoreFeature always returns 0.0 with SolrCloud mode.
• is related to: SOLR-11220 Extracting original score (OriginalScoreFeature) will return 0.0 in SolrCloud