title: Kafka very slow/unresponsive on openstack - how to troubleshoot
body: <p>I am working to create a small Kafka cluster as part of a greater pipeline on a private cloud with Openstack.  In brief, I cannot get Kafka (0.8.2.2 or 0.9.0.0) respond in a timely fashion in even the most basic of scenarios when deployed on a node in Openstack.</p>
  
  <p>After tipping up a single Ubuntu 14.04 server:</p>
  
  <ul>
  <li>Install OpenJDK 8 set JAVA_HOME</li>
  <li>Install Scala 2.11.7 add bin dir to path</li>
  <li>Extract Kafka binary to /opt/kafka (kafka_2.11-0.9.0.0.tgz or kafka_2.11-0.8.2.2.tgz)</li>
  </ul>
  
  <p>Now, following the Quick Start section on the Kafka site (start the built in ZK, start server, create topic, etc.), again nothing fancy, topic creation takes several seconds.  Listing topics can take over 20 seconds.  The console producer seems to work w/o error but no messages ever show up in the console consumer.</p>
  
  <p>I have had similar slowness/failure on three node cluster on top of a three node ZK ensemble on the same nodes.  In an effort to keep the variables minimal, in this mode I only added the advertised.host.name to match the associated floating ip for the node (host.name points to private IP).</p>
  
  <p>The config for broker 0 in this case:</p>
  
  <pre><code>broker.id=0
  advertised.listeners=PLAINTEXT://172.22.0.127:9092
  listeners=PLAINTEXT://:9092
  port=9092
  host.name=10.0.0.92
  advertised.host.name=172.22.0.127
  num.network.threads=3
  num.io.threads=8
  socket.send.buffer.bytes=102400
  socket.receive.buffer.bytes=102400
  socket.request.max.bytes=104857600
  log.dirs=/var/log/kafka
  num.partitions=2
  num.recovery.threads.per.data.dir=1
  log.retention.hours=1
  log.segment.bytes=1073741824
  log.retention.check.interval.ms=300000
  log.cleaner.enable=false
  zookeeper.connect=10.0.0.92:2181,10.0.0.93:2181,10.0.0.94:2181
  zookeeper.connection.timeout.ms=6000
  delete.topic.enable=true
  </code></pre>
  
  <p>I am able to work with Kafka as I would expect on my local machine, local VMs, and even in a Docker container.  This is leading me to believe that there is something with Kafka on Openstack that is no good.  I have found nothing troubling in the logs and no specific errors are being served up which makes this difficult to troubleshoot.</p>
  
  <p>Surprisingly very little comes up when searching for "kafka openstack" in general.  So other than why might  this be happening, I'd also be curious to see if anyone is doing this w/o issues and if so, are there differences that can be identified that might help to uncover what is actually wrong.</p>