[SOLR-14758] NPE in QueryComponent.mergeIds when using timeAllowed and sorting

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 7.7.3, 8.6.3, 9.0, 8.8.1, 8.8.2
• Fix Version/s: 9.0, 8.10
• Component/s: SolrCloud
• Assignee: Uwe Schindler
• Reporter: Bram VD
• Created: 19/Aug/20 15:50
• Updated: 28/Sep/21 20:22
• Resolved: 15/Aug/21 11:19

Description

Only tested on 7.7.3 and master, but the offending code hasn't been changed for a while, so this presumably affects other versions as well.

Steps to reproduce:

1. SolrCloud
2. Create a query which is complex enough to take a while
3. Add a sort clause to the query (e.g. &sort=creationTimestamp asc)
4. Add a short value timeAllowed (10ms in my test)

Result: NPE in QueryComponent.mergeIds:935

It may take a couple of attempts to hit the error.

Offending code:

        NamedList sortFieldValues = (NamedList)(srsp.getSolrResponse().getResponse().get("sort_values"));
        if (sortFieldValues.size()==0 && // we bypass merging this response only if it's partial itself
                            thisResponseIsPartial) { // but not the previous one!!
          continue; //fsv timeout yields empty sort_vlaues
        }

sortFieldValues can apparently be null in some cases, depending on when the query hits the timeAllowed. Adding an extra null check fixes the issue.

        NamedList sortFieldValues = (NamedList)(srsp.getSolrResponse().getResponse().get("sort_values"));
        if ((null == sortFieldValues || sortFieldValues.size()==0) && // we bypass merging this response only if it's partial itself
                            thisResponseIsPartial) { // but not the previous one!!
          continue; //fsv timeout yields empty sort_vlaues
        }

I'll attach a patch.

Issue Links

• is cloned by: SOLR-14674 NPE when TimeAllowed exceeded with sorting
• relates to: SOLR-9882 exceeding timeAllowed causes ClassCastException: BasicResultContext cannot be cast to SolrDocumentList
• relates to: SOLR-14413 allow timeAllowed and cursorMark parameters
• links to: GitHub Pull Request #251