Solr 8 - MiniSolrCloudCluster with multiple servers gives "java.io.IOException: 6/invalid_frame_length" when adding docs

Question

I am creating a MiniSolrCloudCluster instance as shown below. After which i create a collection and then add a document and commit.

final int numServers = 3;

        // random unassigned HTTP port
        final int jettyPort = 0;

        final JettyConfig jettyConfig = JettyConfig.builder().setPort(jettyPort).build();

        // create a MiniSolrCloudCluster instance
        miniSolrCloudCluster = new MiniSolrCloudCluster(numServers, baseDir, jettyConfig);

When i add a document("cloudSolrClient.add(doc);") i get the following strange exception:

18:06:44.627 [updateExecutor-17-thread-1-processing-x:collection1_shard3_replica_n4 r:core_node6 null n:127.0.0.1:56546_solr c:collection1 s:shard3] ERROR org.apache.solr.update.ErrorReportingConcurrentUpdateSolrClient - error java.io.IOException: java.io.IOException: 6/invalid_frame_length

If the numServers=1 then this exception does not show up. It occurs only for numServers>1.

Does any one know the solution for this??

Answer 1

It worked by adding following in @BeforeClass for a Junit Testcase or adding this to the static block so that it runs before everything else:

System.setProperty("jetty.testMode", "true");

Adding this solved above Exception.