title: SparkContext: error initializing SparkContext. java.net.UnknownHostException: master
body: <p>I am new Spark and Intellij. I have my build.sbt file below:</p>
  
  <pre><code>name := "TestSpark"
  version := "1.0"
  scalaVersion := "2.11.8"
  // https://mvnrepository.com/artifact/org.apache.spark/spark-core_2.11
  libraryDependencies ++= Seq("org.apache.spark" % "spark-core_2.11" % "1.6.2","org.apache.hadoop" % "hadoop-client" % "2.6.2")
  </code></pre>
  
  <p>I also have TestMain.scala in src/main/scala-2.11/TestMain.scala</p>
  
  <pre><code>import org.apache.spark.{SparkContext,SparkConf}
  /**
    * Created by tuannv5 on 24/08/2016.
    */
  object TestMain {
    def main(args: Array[String]) {
      val conf = new SparkConf().setMaster("local[*]").setAppName("Test Spark").set("spark.executor.memory","2g")
      val sc = new SparkContext(conf)
      val data = sc.parallelize(1 to 1000000).filter(_&lt;10000)
      data.foreach(println)
  
    }
  }
  </code></pre>
  
  <p>For some reason when I do Run app in Intellij. I get the error:</p>
  
  <pre><code>Using Spark's default log4j profile: org/apache/spark/log4j-defaults.properties
  16/08/24 10:29:28 INFO SparkContext: Running Spark version 1.6.2
  16/08/24 10:29:29 WARN NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
  16/08/24 10:29:29 ERROR SparkContext: Error initializing SparkContext.
  java.net.UnknownHostException: master: master: unknown error
      at java.net.InetAddress.getLocalHost(InetAddress.java:1505)
      at org.apache.spark.util.Utils$.findLocalInetAddress(Utils.scala:789)
      at org.apache.spark.util.Utils$.org$apache$spark$util$Utils$$localIpAddress$lzycompute(Utils.scala:782)
      at org.apache.spark.util.Utils$.org$apache$spark$util$Utils$$localIpAddress(Utils.scala:782)
      at org.apache.spark.util.Utils$$anonfun$localHostName$1.apply(Utils.scala:839)
      at org.apache.spark.util.Utils$$anonfun$localHostName$1.apply(Utils.scala:839)
      at scala.Option.getOrElse(Option.scala:121)
      at org.apache.spark.util.Utils$.localHostName(Utils.scala:839)
      at org.apache.spark.SparkContext.&lt;init&gt;(SparkContext.scala:420)
      at TestMain$.main(TestMain.scala:8)
      at TestMain.main(TestMain.scala)
      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
      at java.lang.reflect.Method.invoke(Method.java:498)
      at com.intellij.rt.execution.application.AppMain.main(AppMain.java:147)
  Caused by: java.net.UnknownHostException: master: unknown error
      at java.net.Inet6AddressImpl.lookupAllHostAddr(Native Method)
      at java.net.InetAddress$2.lookupAllHostAddr(InetAddress.java:928)
      at java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1323)
      at java.net.InetAddress.getLocalHost(InetAddress.java:1500)
      ... 15 more
  16/08/24 10:29:29 INFO SparkContext: Successfully stopped SparkContext
  Exception in thread "main" java.net.UnknownHostException: master: master: unknown error
      at java.net.InetAddress.getLocalHost(InetAddress.java:1505)
      at org.apache.spark.util.Utils$.findLocalInetAddress(Utils.scala:789)
      at org.apache.spark.util.Utils$.org$apache$spark$util$Utils$$localIpAddress$lzycompute(Utils.scala:782)
      at org.apache.spark.util.Utils$.org$apache$spark$util$Utils$$localIpAddress(Utils.scala:782)
      at org.apache.spark.util.Utils$$anonfun$localHostName$1.apply(Utils.scala:839)
      at org.apache.spark.util.Utils$$anonfun$localHostName$1.apply(Utils.scala:839)
      at scala.Option.getOrElse(Option.scala:121)
      at org.apache.spark.util.Utils$.localHostName(Utils.scala:839)
      at org.apache.spark.SparkContext.&lt;init&gt;(SparkContext.scala:420)
      at TestMain$.main(TestMain.scala:8)
      at TestMain.main(TestMain.scala)
      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
      at java.lang.reflect.Method.invoke(Method.java:498)
      at com.intellij.rt.execution.application.AppMain.main(AppMain.java:147)
  Caused by: java.net.UnknownHostException: master: unknown error
      at java.net.Inet6AddressImpl.lookupAllHostAddr(Native Method)
      at java.net.InetAddress$2.lookupAllHostAddr(InetAddress.java:928)
      at java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1323)
      at java.net.InetAddress.getLocalHost(InetAddress.java:1500)
      ... 15 more
  
  Process finished with exit code 1
  </code></pre>
  
  <p>Can someone please explain to me the problem stated in this error? Is this because my dependencies were not installed correctly or is it because of another reason?</p>