title: hbase can not connect to zookeeper?
body: <p>I run hbase with <code>start-hbase.sh</code>, but the log file output exception as follow:</p>
  
  <pre><code>2015-09-12 18:39:37,935 WARN  [RS:0;roger-ubuntu:54809-SendThread(localhost:2181)] zookeeper.ClientCnxn: Session 0x14fc12354a40004 for server null, unexpected error, closing socket connection and attempting reconnect
  java.net.ConnectException: 拒绝连接
      at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
      at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:740)
      at org.apache.zookeeper.ClientCnxnSocketNIO.doTransport(ClientCnxnSocketNIO.java:361)
      at org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:1081)
  </code></pre>
  
  <p>According to Exception, hbase can not connect to zookeeper, but this hbase should run a zookeeper for self.</p>
  
  <p>here is my <code>hbase-site.xml</code>:</p>
  
  <pre><code>&lt;configuration&gt;
      &lt;property&gt;
          &lt;name&gt;hbase.coprocessor.region.classes&lt;/name&gt;
          &lt;value&gt;com.gzhdi.coprocessor.HelloWorldEndPoint&lt;/value&gt;
      &lt;/property&gt;
  &lt;/configuration&gt;
  </code></pre>
  
  <p>and my <code>hbase-env.sh</code>:</p>
  
  <pre><code>export HBASE_OPTS="-XX:+UseConcMarkSweepGC"
  </code></pre>