[SOLR-14700] CloudSolrClient cannot be used without setting an explicit streamContext

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 8.6
• Fix Version/s: 8.7, 9.0
• Component/s: clients - java
• Assignee: Unassigned
• Reporter: Mads Bondo Dydensborg
• Created: 01/Aug/20 13:52
• Updated: 27/Jan/21 11:20
• Resolved: 24/Aug/20 12:25

Description

A naive approach to using CloudSolrClient, such as on this page: http://joelsolr.blogspot.com/2015/04/the-streaming-api-solrjio-basics.html - will not work: opening the stream will throw an IOException with an embedded NullPointerException.

This took me a while to figure out, and I think it would be good to either update the documentation or "fix" the constructor to set the needed streamContext as appropriate.

I found this snippet of code in TuppleStream.java, that seems to "almost" work without a streamContext:

// line 127 in the sources to TuppleStream.java:
public static List<String> getShards(String zkHost,
                                       String collection,
                                       StreamContext streamContext,
                                       SolrParams requestParams)
...

// line 135
if(streamContext != null) {
      shardsMap = (Map<String, List<String>>)streamContext.get("shards");
    }
...
// line 144
CloudSolrClient cloudSolrClient =
          Optional.ofNullable(streamContext.getSolrClientCache()).orElseGet(SolrClientCache::new).getCloudSolrClient(zkHost);

if streamContext is null in the last statement, a NullPointerException will be thrown and open'ening the stream will fail.

This took me way too long time to figure out.

Issue Links

• links to: GitHub Pull Request #1754