Stop counting preemption of executors as failure

Author: Ashwin Shankar

yarn/src/main/scala/org/apache/spark/deploy/yarn/YarnAllocator.scala

@@ -373,7 +373,11 @@ private[yarn] class YarnAllocator(
         // Hadoop 2.2.X added a ContainerExitStatus we should switch to use
         // there are some exit status' we shouldn't necessarily count against us, but for
         // now I think its ok as none of the containers are expected to exit
-        if (completedContainer.getExitStatus == -103) { // vmem limit exceeded
+        if (completedContainer.getExitStatus == ContainerExitStatus.PREEMPTED) {
+          logInfo("Container killed: " + containerId +
+            ". Exit status: " + completedContainer.getExitStatus +
+            ". Diagnostics: " + completedContainer.getDiagnostics)
+        } else if (completedContainer.getExitStatus == -103) { // vmem limit exceeded
           logWarning(memLimitExceededLogMessage(
             completedContainer.getDiagnostics,
             VMEM_EXCEEDED_PATTERN))