title: Running Sparkling-Water with external H2O backend
body: <p>I was following the steps for running Sparkling water with external backend from <a href="https://github.com/h2oai/sparkling-water/blob/master/doc/backends.md#manual-mode-of-external-backend" rel="nofollow noreferrer">here</a>. I am using <code>spark 1.4.1</code>, <code>sparkling-water-1.4.16</code>, I've build the extended h2o jar and exported the <code>H2O_ORIGINAL_JAR</code> and <code>H2O_EXTENDED_JAR</code> system variables. I start the h2o backend with </p>
  
  <pre><code>java -jar $H2O_EXTENDED_JAR -md5skip -name test
  </code></pre>
  
  <p>But when I start sparkling water via </p>
  
  <pre><code>./bin/sparkling-shell
  </code></pre>
  
  <p>and in it try to get the <code>H2OConf</code> with </p>
  
  <pre><code>import org.apache.spark.h2o._
  val conf = new H2OConf(sc).setExternalClusterMode().useManualClusterStart().setCloudName("test”)
  val hc = H2OContext.getOrCreate(sc, conf)
  </code></pre>
  
  <p>it fails on the second line with </p>
  
  <pre><code>&lt;console&gt;:24: error: trait H2OConf is abstract; cannot be instantiated
     val conf = new H2OConf(sc).setExternalClusterMode().useManualClusterStart().setCloudName("test")
                ^
  </code></pre>
  
  <p>I've tried adding the newly build extended h2o jar with <code>--jars</code> parameter either to sparkling water or standalone spark with no progress. Does any one have any hints? </p>