title: spark standalone cluster slave unable to connect slave to master
body: <p>i have the bin for spark-1.6.0-bin-hadoop2.6 im having issue trying to connect the slave to the master
  so far i have tried(on ubuntu 14.04 live usb):  </p>
  
  <ol>
  <li><p>apt-get purge and install openssh-client and server on both systems </p></li>
  <li><p>I have stated explicitly the ip address of the master in the spark  url for the worker 
  spark://&lt; master ip>:7077 and also tried changing the SPARK_MASTER_IP in /conf/spark-env.sh the worker executes but the log has the following error 
  im assuming  there must be some ssh setup     involved but i have tried ssh-keygen and ssh-copy-id @ it also doesnt give any reuslts </p>
  
  <pre><code>16/02/22 07:49:16 INFO Worker: Connecting to master 192.168.0.208:7077...
  16/02/22 07:49:16 WARN Worker: Failed to connect to master 192.168.0.208:7077
  java.io.IOException: Failed to connect to /192.168.0.208:7077
  at org.apache.spark.network.client.TransportClientFactory.createClient(TransportClientFactory.java:216)
  at org.apache.spark.network.client.TransportClientFactory.createClient(TransportClientFactory.java:167)
  at org.apache.spark.rpc.netty.NettyRpcEnv.createClient(NettyRpcEnv.scala:200)
  at org.apache.spark.rpc.netty.Outbox$$anon$1.call(Outbox.scala:187)
  at org.apache.spark.rpc.netty.Outbox$$anon$1.call(Outbox.scala:183)
  at java.util.concurrent.FutureTask.run(FutureTask.java:262)
  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
  at java.lang.Thread.run(Thread.java:745)
  Caused by: java.net.ConnectException: Connection refused: /192.168.0.208:7077
  at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
  at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:740)
  at io.netty.channel.socket.nio.NioSocketChannel.doFinishConnect(NioSocketChannel.java:224)
  at io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.finishConnect(AbstractNioChannel.java:289)
  at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:528)
  at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:468)
  at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:382)
  at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:354)
  at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:111)
  ... 1 more
  </code></pre>
  
  <p>16/02/22 07:49:27 INFO Worker: Retrying connection to master (attempt # 2)</p></li>
  </ol>
  
  <p>i am however able to open the master webUI by typing :8080 on my browser    . i am also able to access the webUI of the slave from the master . im almost at the point of giving in so please helllppp.</p>