Why does Spark job fail with "Exit code: 52" : <p>I have had Spark job failing with a trace like this one:</p>

<pre><code>./containers/application_1455622885057_0016/container_1455622885057_0016_01_000001/stderr-Container id: container_1455622885057_0016_01_000008
./containers/application_1455622885057_0016/container_1455622885057_0016_01_000001/stderr-Exit code: 52
./containers/application_1455622885057_0016/container_1455622885057_0016_01_000001/stderr:Stack trace: ExitCodeException exitCode=52: 
./containers/application_1455622885057_0016/container_1455622885057_0016_01_000001/stderr-      at org.apache.hadoop.util.Shell.runCommand(Shell.java:545)
./containers/application_1455622885057_0016/container_1455622885057_0016_01_000001/stderr-      at org.apache.hadoop.util.Shell.run(Shell.java:456)
./containers/application_1455622885057_0016/container_1455622885057_0016_01_000001/stderr-      at org.apache.hadoop.util.Shell$ShellCommandExecutor.execute(Shell.java:722)
./containers/application_1455622885057_0016/container_1455622885057_0016_01_000001/stderr-      at org.apache.hadoop.yarn.server.nodemanager.DefaultContainerExecutor.launchContainer(DefaultContainerExecutor.java:211)
./containers/application_1455622885057_0016/container_1455622885057_0016_01_000001/stderr-      at org.apache.hadoop.yarn.server.nodemanager.containermanager.launcher.ContainerLaunch.call(ContainerLaunch.java:302)
./containers/application_1455622885057_0016/container_1455622885057_0016_01_000001/stderr-      at org.apache.hadoop.yarn.server.nodemanager.containermanager.launcher.ContainerLaunch.call(ContainerLaunch.java:82)
./containers/application_1455622885057_0016/container_1455622885057_0016_01_000001/stderr-      at java.util.concurrent.FutureTask.run(FutureTask.java:262)
./containers/application_1455622885057_0016/container_1455622885057_0016_01_000001/stderr-      at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
./containers/application_1455622885057_0016/container_1455622885057_0016_01_000001/stderr-      at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
./containers/application_1455622885057_0016/container_1455622885057_0016_01_000001/stderr-      at java.lang.Thread.run(Thread.java:745)
./containers/application_1455622885057_0016/container_1455622885057_0016_01_000001/stderr-
./containers/application_1455622885057_0016/container_1455622885057_0016_01_000001/stderr-
./containers/application_1455622885057_0016/container_1455622885057_0016_01_000001/stderr-Container exited with a non-zero exit code 52
</code></pre>

<p>It took me a while to figure out what "exit code 52" means, so I'm putting this up here for the benefit of others who might be searching</p>
