[SOLR-12878] FacetFieldProcessorByHashDV is reconstructing FieldInfos on every instantiation

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Duplicate
• Affects Version/s: 7.5
• Fix Version/s: 7.6, 8.0
• Component/s: Facet Module
• Labels: performance
• Assignee: David Smiley
• Reporter: Tim Underwood
• Created: 17/Oct/18 15:31
• Updated: 08/Jun/19 15:02
• Resolved: 06/Nov/18 20:46

Description

The FacetFieldProcessorByHashDV constructor is currently calling:

FieldInfo fieldInfo = fcontext.searcher.getSlowAtomicReader().getFieldInfos().fieldInfo(sf.getName());

Which is reconstructing FieldInfos each time. Simply switching it to:

FieldInfo fieldInfo = fcontext.searcher.getFieldInfos().fieldInfo(sf.getName());

 
causes it to use the cached version of FieldInfos in the SolrIndexSearcher.

On my index the FacetFieldProcessorByHashDV is 2-3 times slower than the legacy facets without this fix.

Issue Links

• is superceded by: LUCENE-8557 LeafReader.getFieldInfos should always return the same instance
• links to: GitHub Pull Request #473
• links to: GitHub Pull Request #473