Solr core reload fails with java.lang.RuntimeException from org.apache.solr.spelling.suggest.fst.BlendedInfixLookupFactory.create()

Summary

DataStax Enterprise 4.7 nodes running in Search mode fails to reload cores with a RuntimeException when using the BlendedInfixLookupFactory Suggester class.

Symptoms

An attempt to reload an existing core returns the following exception stack trace:

ERROR [http-8983-exec-3] 2015-06-12 20:05:54,143  SolrException.java:150 - org.apache.solr.common.SolrException
  at org.apache.solr.core.SolrCore.(SolrCore.java:906)
...
Caused by: java.lang.RuntimeException
  at org.apache.solr.spelling.suggest.fst.BlendedInfixLookupFactory.create(BlendedInfixLookupFactory.java:127)
  at org.apache.solr.spelling.suggest.SolrSuggester.init(SolrSuggester.java:106)
  at org.apache.solr.handler.component.SuggestComponent.inform(SuggestComponent.java:113)
  at org.apache.solr.core.SolrResourceLoader.inform(SolrResourceLoader.java:655)
  at org.apache.solr.core.SolrCore.(SolrCore.java:889)
...

Cause

The BlendedInfixLookupFactory extends the AnalyzingInfixSuggester class.

The issue is that when the core is reloaded, a new instance of AnalyzingInfixSuggester is created which in turn creates a new writer on an existing directory but it cannot get a lock so Solr fails to reload the core (bug ID SOLR-6246).

Solution

At the time of writing, the defect in the open-source Solr has not been fixed and is not targetted until Solr version 5.2 (note that DSE 4.7 ships with Solr 4.10.3.0).

The BlendedInfixLookupFactory class is still experimental as of Solr 4.10.3.0 and so our recommendation is to not use it until the defect is resolved in a future release.

See also

DataStax Enterprise 4.7 Release notes.

The BlendedInfixLookupFactory class API documentation.

Defect - [SOLR-6246] "Core fails to reload when AnalyzingInfixSuggester is used as a Suggester".