title: Kafka startup fails with zookeeper timeout (remote server), yet the machine can connect to zookeeper directly
body: <p>WHen I start kafka up, it fails quickly while complaining that it cannot connect to zookeeper.  I am running zookeeper as a standalone cluster/ensemble.  I am confused because there is no Firewall between the servers (as evidenced by the zookeeper-shell.sh test).</p>
  
  <p>from /var/log/kafka/server.log</p>
  
  <pre><code>2016-02-24 16:07:12,101 INFO kafka.server.KafkaServer: [Kafka Server 1], Connecting to zookeeper on 10.7.20.100:2181,10.7.20.101:2181,10.7.20.102:2181
  2016-02-24 16:07:20,291 FATAL kafka.server.KafkaServerStartable: Fatal error during KafkaServerStable startup. Prepare to shutdown
  org.I0Itec.zkclient.exception.ZkTimeoutException: Unable to connect to zookeeper server within timeout: 6000
      at org.I0Itec.zkclient.ZkClient.connect(ZkClient.java:880)
      at org.I0Itec.zkclient.ZkClient.&lt;init&gt;(ZkClient.java:98)
      at org.I0Itec.zkclient.ZkClient.&lt;init&gt;(ZkClient.java:84)
      at kafka.server.KafkaServer.initZk(KafkaServer.scala:113)
      at kafka.server.KafkaServer.startup(KafkaServer.scala:69)
      at kafka.server.KafkaServerStartable.startup(KafkaServerStartable.scala:34)
      at kafka.Kafka$.main(Kafka.scala:46)
      at kafka.Kafka.main(Kafka.scala)
  2016-02-24 16:07:20,294 INFO kafka.server.KafkaServer: [Kafka Server 1], shutting down
  2016-02-24 16:07:20,312 INFO kafka.server.KafkaServer: [Kafka Server 1], shut down completed
  2016-02-24 16:07:20,317 INFO kafka.server.KafkaServer: [Kafka Server 1], shutting down
  </code></pre>
  
  <p>However from the /opt/kafka install directory I am able to connect to zookeeper using the esemble connection string - so I really doubt it is network OR firewall.</p>
  
  <pre><code>[me@dckafka01 kafka]$ cd /opt/kafka
  [me@dckafka01 kafka]$ bin/zookeeper-shell.sh 10.7.20.100:2181,10.7.20.101:2181,10.7.20.102:2181
  
  Connecting to 10.7.20.100:2181,10.7.20.101:2181,10.7.20.102:2181
  Welcome to ZooKeeper!
  JLine support is disabled
  WATCHER::WatchedEvent state:SyncConnected type:None path:null
  
  get /blah
  null
  cZxid = 0x400000009
  ctime = Tue Feb 16 09:00:28 EST 2016
  mZxid = 0x400000009
  mtime = Tue Feb 16 09:00:28 EST 2016
  pZxid = 0x40000017e
  cversion = 2
  dataVersion = 0
  aclVersion = 0
  ephemeralOwner = 0x0
  dataLength = 0
  numChildren = 2
  
  ls /blah
  [applications, registry]
  </code></pre>
  
  <p>Which is as expected.   Does anybody have an angle for me to investigate?</p>