[SOLR-10428] CloudSolrClient: Qerying multiple collection aliases leads to SolrException: Collection not found

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 6.4, 6.4.1, 6.4.2, 6.5, 7.0
• Fix Version/s: 7.2
• Component/s: SolrJ
• Assignee: Unassigned
• Reporter: Philip Pock
• Created: 05/Apr/17 22:51
• Updated: 08/Jun/19 15:21
• Resolved: 15/Jun/18 15:15

Description

We have multiple collections and an alias is created for each of them. e.g.:
alias-a -> collection-a, alias-b -> collection-b

We search in multiple collections by passing the aliases of the collections in the collections parameter.

solrClient.query("alias-a,alias-b", params, SolrRequest.METHOD.POST)

The client can't find the collection and throws an Exception. Relevant parts of the stacktrace using v6.5.0:

org.apache.solr.common.SolrException: Collection not found: collection-a
	at org.apache.solr.client.solrj.impl.CloudSolrClient.getCollectionNames(CloudSolrClient.java:1394)
	at org.apache.solr.client.solrj.impl.CloudSolrClient.requestWithRetryOnStaleState(CloudSolrClient.java:1087)
	at org.apache.solr.client.solrj.impl.CloudSolrClient.request(CloudSolrClient.java:1057)
	at org.apache.solr.client.solrj.SolrRequest.process(SolrRequest.java:160)
	at org.apache.solr.client.solrj.SolrClient.query(SolrClient.java:974)

Everything works fine with a single alias.
I think this issue was introduced with SOLR-9784. Please see my comment below.

org.apache.solr.client.solrj.impl.CloudSolrClient

Set<String> getCollectionNames(String collection) {
    List<String> rawCollectionsList = StrUtils.splitSmart(collection, ",", true);
    Set<String> collectionNames = new HashSet<>();
    for (String collectionName : rawCollectionsList) {
      if (stateProvider.getState(collectionName) == null) {
        // I assume that collectionName should be passed to getAlias here
        String alias = stateProvider.getAlias(collection);
        if (alias != null) {
          List<String> aliasList = StrUtils.splitSmart(alias, ",", true);
          collectionNames.addAll(aliasList);
          continue;
        }

          throw new SolrException(ErrorCode.BAD_REQUEST, "Collection not found: " + collectionName);
        }

      collectionNames.add(collectionName);
    }
    return collectionNames;
  }

The suggested change is similar to the previous revision: https://github.com/apache/lucene-solr/commit/5650939a8d41b7bad584947a2c9dcedf3774b8de#diff-c8d54eacd46180b332c86c7ae448abaeL1301