title: Confluent Control center not showing system health (for a Multi-Cluster Configuration)
body: <p>I'm having trouble getting control-center to work. Setted up a 3 node kafka cluster using the following docker image = confluentinc/cp-enterprise-kafka. On a separate machine I've downloaded confluent platform v5.0.1 and I've configured (tried) control-center to monitor the docker cluster.</p>
  
  <p>The kafka broker I'm using for the control-center configuration is the same from the confluent platform v5.0.1, downloaded.(I start the whole stack via bin/confluent start)</p>
  
  <p>But I keep getting the rocket launching page when clicking Monitoring > System health.</p>
  
  <p>My setup : --------------------------------------------------------</p>
  
  <ul>
  <li>3 node kafka cluster using docker images.</li>
  <li>docker image used = confluentinc/cp-enterprise-kafka</li>
  </ul>
  
  <p>kafka running on these hostnames for the 3-node cluster :</p>
  
  <ul>
  <li>os0 / running on tcp/29092</li>
  <li>os1 / running on tcp/39092 </li>
  <li>os2 / running on tcp/49092</li>
  </ul>
  
  <p>Control-center is running on a separate machine whose hostname = sb1</p>
  
  <p>Futhermore the brokers have the following directives defined as :</p>
  
  <ul>
  <li>metric.reporters=io.confluent.metrics.reporter.ConfluentMetricsReporter </li>
  <li>confluent.metrics.reporter.bootstrap.servers=sb1:9092</li>
  </ul>
  
  <p>For the control-center I added the 3 node cluster config :</p>
  
  <ul>
  <li>confluent.controlcenter.kafka.osd.bootstrap.servers=os0:29092,os1:39092,os2:49092</li>
  </ul>
  
  <hr>
  
  <p>I'm expecting the kafka brokers writing to the kafka broker @ sb1 (used by control-center) topic _confluent-metrics</p>
  
  <p>What I've tried/checked/debugged so far :</p>
  
  <ul>
  <li>dumped the the topic _confluent-metrics, and I have messages being written there</li>
  <li>I dont know if logs from control-center (@ /tmp/confluent.QJ2C4BmE/control-center/control-center.stdout) do show anyhting useful (at least for what I can interpret)
  
  <ul>
  <li>I can see HTTP/200 for the cluster I'm trying to monitor written down in the blog.</li>
  </ul></li>
  <li>at the log from the kafka brokers I also see written the following, which put me thinking the messages were written to the topic :
  [2018-12-15 07:57:59,893] ERROR Failed to submit metrics to Kafka topic __confluent.support.metrics (due to exception): java.util.concurrent.ExecutionException: org.apache.kafka.common.errors.TimeoutException: Expiring 1 record(s) for __confluent.support.metrics-0: 30083 ms has passed since batch creation plus linger time (io.confluent.support.metrics.submitters.KafkaSubmitter)
  [2018-12-15 07:58:01,088] INFO Successfully submitted metrics to Confluent via secure endpoint (io.confluent.support.metrics.submitters.ConfluentSubmitter)</li>
  </ul>
  
  <p>I run out of viable solutions to debug this, any help would be appreciated.</p>
  
  <p>thanks in advance.</p>