[spark] Kill session when it fails to start

15/08/10 11:16:31 WARN security.UserGroupInformation: PriviledgedActionException as:romain (auth:PROXY) via romain (auth:SIMPLE) cause:java.io.IOException: Cannot run program "sparkR": error=2, No such file or directory
Exception in thread "main" java.io.IOException: Cannot run program "sparkR": error=2, No such file or directory
	at java.lang.ProcessBuilder.start(ProcessBuilder.java:1047)
	at com.cloudera.hue.livy.repl.sparkr.SparkRSession$.create(SparkRSession.scala:44)
	at com.cloudera.hue.livy.repl.ScalatraBootstrap.init(Main.scala:107)
	at org.scalatra.servlet.ScalatraListener.configureCycleClass(ScalatraListener.scala:67)
	at org.scalatra.servlet.ScalatraListener.contextInitialized(ScalatraListener.scala:23)
	at com.cloudera.hue.jetty.server.handler.ContextHandler.callContextInitialized(ContextHandler.java:800)
	at com.cloudera.hue.jetty.servlet.ServletContextHandler.callContextInitialized(ServletContextHandler.java:444)
	at com.cloudera.hue.jetty.server.handler.ContextHandler.startContext(ContextHandler.java:791)
	at com.cloudera.hue.jetty.servlet.ServletContextHandler.startContext(ServletContextHandler.java:294)
	at com.cloudera.hue.jetty.server.handler.ContextHandler.doStart(ContextHandler.java:741)
	at com.cloudera.hue.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
	at com.cloudera.hue.jetty.util.component.ContainerLifeCycle.start(ContainerLifeCycle.java:132)
	at com.cloudera.hue.jetty.util.component.ContainerLifeCycle.doStart(ContainerLifeCycle.java:114)
	at com.cloudera.hue.jetty.server.handler.AbstractHandler.doStart(AbstractHandler.java:61)
	at com.cloudera.hue.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
	at com.cloudera.hue.jetty.util.component.ContainerLifeCycle.start(ContainerLifeCycle.java:132)
	at com.cloudera.hue.jetty.server.Server.start(Server.java:387)
	at com.cloudera.hue.jetty.util.component.ContainerLifeCycle.doStart(ContainerLifeCycle.java:114)
	at com.cloudera.hue.jetty.server.handler.AbstractHandler.doStart(AbstractHandler.java:61)
	at com.cloudera.hue.jetty.server.Server.doStart(Server.java:354)
	at com.cloudera.hue.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
	at com.cloudera.hue.livy.WebServer.start(WebServer.scala:64)
	at com.cloudera.hue.livy.repl.Main$.main(Main.scala:78)
	at com.cloudera.hue.livy.repl.Main.main(Main.scala)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:606)
	at org.apache.spark.deploy.SparkSubmit$.org$apache$spark$deploy$SparkSubmit$$runMain(SparkSubmit.scala:666)
	at org.apache.spark.deploy.SparkSubmit$$anon$1.run(SparkSubmit.scala:160)
	at org.apache.spark.deploy.SparkSubmit$$anon$1.run(SparkSubmit.scala:158)
	at java.security.AccessController.doPrivileged(Native Method)
	at javax.security.auth.Subject.doAs(Subject.java:415)
	at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1671)
	at org.apache.spark.deploy.SparkSubmit$.doRunMain$1(SparkSubmit.scala:158)
	at org.apache.spark.deploy.SparkSubmit$.submit(SparkSubmit.scala:203)
	at org.apache.spark.deploy.SparkSubmit$.main(SparkSubmit.scala:118)
	at org.apache.spark.deploy.SparkSubmit.main(SparkSubmit.scala)
Caused by: java.io.IOException: error=2, No such file or directory
	at java.lang.UNIXProcess.forkAndExec(Native Method)
	at java.lang.UNIXProcess.<init>(UNIXProcess.java:187)
	at java.lang.ProcessImpl.start(ProcessImpl.java:130)
	at java.lang.Proc