[SOLR-10190] Potential NPE in CloudSolrClient when reading stale alias

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 5.5, 7.0
• Fix Version/s: 6.4.2, 6.5, 7.0
• Component/s: clients - java, SolrJ
• Assignee: Tomas Eduardo Fernandez Lobbe
• Reporter: Janosch Woschitz
• Created: 22/Feb/17 14:54
• Updated: 08/Jun/19 15:30
• Resolved: 27/Feb/17 17:55

Description

The CloudSolrClient raises a NullPointerException when CloudSolrClient::add is invoked and pointed to an alias which references a collection which does not exist anymore.

java.lang.NullPointerException
    at __randomizedtesting.SeedInfo.seed([1D00539A964E5C5D:D7D145363AD5CCA]:0)
    at org.apache.solr.client.solrj.impl.CloudSolrClient.requestWithRetryOnStaleState(CloudSolrClient.java:1078)
    at org.apache.solr.client.solrj.impl.CloudSolrClient.request(CloudSolrClient.java:1042)
    at org.apache.solr.client.solrj.SolrRequest.process(SolrRequest.java:160)
    at org.apache.solr.client.solrj.SolrClient.add(SolrClient.java:106)
    at org.apache.solr.client.solrj.SolrClient.add(SolrClient.java:71)
    at org.apache.solr.client.solrj.SolrClient.add(SolrClient.java:85)

This is a rather unexpected since the CloudSolrClient usually raises a SolrException containing a descriptive error message (e.g. "Collection not found: xyz") when a collection cannot be resolved.

In general this error condition could be triggered also by other edge cases since CloudSolrClient::getDocCollection might return null but the code following that invocation is not guarded against null values.

        // track the version of state we're using on the client side using the _stateVer_ param
        DocCollection coll = getDocCollection(requestedCollection, null);
        int collVer = coll.getZNodeVersion();

Issue Links

• links to: GitHub Pull Request #160