[adding dev list since it's probably a bug, but i'm not sure how to reproduce so I can open a bug about it]
Hi, I have a standalone Spark 1.4.0 cluster with 100s of applications running every day. >From time to time, the applications crash with the following error (see below) But at the same time (and also after that), other applications are running, so I can safely assume the master and workers are working. 1. why is there a NullPointerException? (i can't track the scala stack trace to the code, but anyway NPE is usually a obvious bug even if there's actually a network error...) 2. why can't it connect to the master? (if it's a network timeout, how to increase it? i see the values are hardcoded inside AppClient) 3. how to recover from this error? ERROR 01-11 15:32:54,991 SparkDeploySchedulerBackend - Application has been killed. Reason: All masters are unresponsive! Giving up. ERROR ERROR 01-11 15:32:55,087 OneForOneStrategy - ERROR logs/error.log java.lang.NullPointerException NullPointerException at org.apache.spark.deploy.client.AppClient$ClientActor$$anonfun$receiveWithLogging$1.applyOrElse(AppClient.scala:160) at scala.runtime.AbstractPartialFunction$mcVL$sp.apply$mcVL$sp(AbstractPartialFunction.scala:33) at scala.runtime.AbstractPartialFunction$mcVL$sp.apply(AbstractPartialFunction.scala:33) at scala.runtime.AbstractPartialFunction$mcVL$sp.apply(AbstractPartialFunction.scala:25) at org.apache.spark.util.ActorLogReceive$$anon$1.apply(ActorLogReceive.scala:59) at org.apache.spark.util.ActorLogReceive$$anon$1.apply(ActorLogReceive.scala:42) at scala.PartialFunction$class.applyOrElse(PartialFunction.scala:118) at org.apache.spark.util.ActorLogReceive$$anon$1.applyOrElse(ActorLogReceive.scala:42) at akka.actor.Actor$class.aroundReceive(Actor.scala:465) at org.apache.spark.deploy.client.AppClient$ClientActor.aroundReceive(AppClient.scala:61) at akka.actor.ActorCell.receiveMessage(ActorCell.scala:516) at akka.actor.ActorCell.invoke(ActorCell.scala:487) at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:238) at akka.dispatch.Mailbox.run(Mailbox.scala:220) at akka.dispatch.ForkJoinExecutorConfigurator$AkkaForkJoinTask.exec(AbstractDispatcher.scala:393) at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260) at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339) at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979) at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107) ERROR 01-11 15:32:55,603 SparkContext - Error initializing SparkContext. ERROR java.lang.IllegalStateException: Cannot call methods on a stopped SparkContext at org.apache.spark.SparkContext.org $apache$spark$SparkContext$$assertNotStopped(SparkContext.scala:103) at org.apache.spark.SparkContext.getSchedulingMode(SparkContext.scala:1501) at org.apache.spark.SparkContext.postEnvironmentUpdate(SparkContext.scala:2005) at org.apache.spark.SparkContext.<init>(SparkContext.scala:543) at org.apache.spark.api.java.JavaSparkContext.<init>(JavaSparkContext.scala:61) Thanks! *Romi Kuntsman*, *Big Data Engineer* http://www.totango.com