SAMZA-2231: Exception thrown during yarn staging directory cleanup masks original exception

Failures cleaning up the staging directory on another exception were masking the original exception making troubleshooting difficult. Add some logging and an extra try/catch around the cleanup.

Author: thunderstumpges <[email protected]>

Reviewers: Daniel Nishimura <[email protected]>

Closes apache#1059 from thunderstumpges/try-catch-on-staging-cleanup

Author: thunderstumpges

samza-yarn/src/main/scala/org/apache/samza/job/yarn/YarnJob.scala

@@ -71,8 +71,16 @@ class YarnJob(config: Config, hadoopConfig: Configuration) extends StreamJob {
       )
     } catch {
       case e: Throwable =>
-        client.cleanupStagingDir
-        throw e
+        logger.error("Exception submitting yarn job.", e )
+        try {
+          // try to clean up. this may throw an exception depending on how far into launching the job we got.
+          // we don't want to mask the original problem by throwing this.
+          client.cleanupStagingDir
+        } catch {
+          case ce: Throwable => logger.warn("Exception cleaning Staging Directory after failed launch attempt.", ce)
+        } finally {
+          throw e
+        }
     }
 
     this