[SOLR-7759] DebugComponent's explain should be implemented as a distributed query

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 8.3
• Assignee: Andrzej Bialecki
• Reporter: Varun Thacker
• Created: 06/Jul/15 16:25
• Updated: 03/Nov/22 22:18
• Resolved: 03/Nov/22 22:18

Description

Currently when we use debugQuery to see the explanation of the matched documents, the query fired to get the statistics for the matched documents is not a distributed query.

This is a problem when using distributed idf. The actual documents are being scored using the global stats and not per shard stats , but the explain will show us the score by taking into account the stats from the shard where the document belongs to.

We should try to implement the explain query as a distributed request so that the scores match the actual document scores.

Issue Links

• duplicates: SOLR-8061 GlobalStats, incorrect order of debug results
• is fixed by: SOLR-13790 LRUStatsCache size explosion and ineffective caching