Solr集群组件如何工作？

Question

I was looking(in process of making my own) into solr's default clustering component for carrot2. In the clustering component class there are 2 methods where the clustering algorithms are called:

• in the overridden process method

   SolrDocumentList solrDocList = SolrPluginUtils.docListToSolrDocumentList( results.docList, rb.req.getSearcher(), engine.getFieldsToLoad(rb.req),docIds); Object clusters = engine.cluster(rb.getQuery(), solrDocList, docIds, rb.req); rb.rsp.add("clusters", clusters); 

• And once again in the finishStage method

   Map<SolrDocument,Integer> docIds = null; Object clusters = engine.cluster(rb.getQuery(), solrDocList, docIds, rb.req); rb.rsp.add("clusters", clusters); 

Now my question is the process method works not on the complete result query but on the shards and finish stage os when all the results have been aggregated, then why does we call the clustering algorithms twice and adding it to the result state?Am I missing something?

Clustering component code here .

PS Please correct me if I am wrong.

Answer 1

Looks like a bug to me (and I see it's actually called twice in distributed mode). I'll look into this, see SOLR-10678 to track it.