[SOLR-12852] NPE in ClusteringComponent

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Cannot Reproduce
• Affects Version/s: 7.5
• Fix Version/s: 8.2, 9.0
• Component/s: contrib - Clustering
• Assignee: Dawid Weiss
• Reporter: Markus Jelsma
• Created: 11/Oct/18 14:49
• Updated: 12/May/22 00:26
• Resolved: 29/Sep/20 07:14

Description

Got this exception:

 o.a.s.s.HttpSolrCall null:java.lang.NullPointerException
        at org.apache.solr.handler.clustering.ClusteringComponent.process(ClusteringComponent.java:234)
        at org.apache.solr.handler.component.SearchHandler.handleRequestBody(SearchHandler.java:298)
        at org.apache.solr.handler.RequestHandlerBase.handleRequest(RequestHandlerBase.java:199)
        at org.apache.solr.core.SolrCore.execute(SolrCore.java:2541)
        at org.apache.solr.servlet.HttpSolrCall.execute(HttpSolrCall.java:709)
        at org.apache.solr.servlet.HttpSolrCall.call(HttpSolrCall.java:515)
        at org.apache.solr.servlet.SolrDispatchFilter.doFilter(SolrDispatchFilter.java:377)
        at org.apache.solr.servlet.SolrDispatchFilter.doFilter(SolrDispatchFilter.java:323)

with this config (copied from reference guide, changed title and snippet parameters)

  <searchComponent name="clustering" class="solr.clustering.ClusteringComponent">
    <!-- Lingo clustering algorithm -->
    <lst name="engine">
      <str name="name">lingo</str>
      <str name="carrot.algorithm">org.carrot2.clustering.lingo.LingoClusteringAlgorithm</str>
    </lst>

    <!-- An example definition for the STC clustering algorithm. -->
    <lst name="engine">
      <str name="name">stc</str>
      <str name="carrot.algorithm">org.carrot2.clustering.stc.STCClusteringAlgorithm</str>
    </lst>
  </searchComponent>
  
  <requestHandler name="/clustering"
                  class="solr.SearchHandler">
    <lst name="defaults">
      <bool name="clustering">true</bool>
      <bool name="clustering.results">true</bool>

      <!-- Logical field to physical field mapping. -->
      <str name="carrot.url">id</str>
      <str name="carrot.title">title_nl</str>
      <str name="carrot.snippet">content_nl</str>

      <!-- Configure any other request handler parameters. We will cluster the
          top 100 search results so bump up the 'rows' parameter. -->
      <str name="rows">100</str>
      <str name="fl">*,score</str>
    </lst>

    <!-- Append clustering at the end of the list of search components. -->
    <arr name="last-components">
      <str>clustering</str>
    </arr>
  </requestHandler>

using this query:
http://localhost:8983/solr/collection/clustering?q=*:*

All libraries are present, Solr no longer complains about missing classes, instead i got this.

Issue Links

• is part of: SOLR-14926 Modernize and clean up document clustering contrib