YARN-3237. AppLogAggregatorImpl fails to log error cause. Contributed by

Rushabh S Shah

hadoop-yarn-project/CHANGES.txt

@@ -312,6 +312,9 @@ Release 2.7.0 - UNRELEASED
 
     YARN-3230. Clarify application states on the web UI. (Jian He via wangda)
 
+    YARN-3237. AppLogAggregatorImpl fails to log error cause.
+    (Rushabh S Shah via xgong)
+
   OPTIMIZATIONS
 
     YARN-2990. FairScheduler's delay-scheduling always waits for node-local and 

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/logaggregation/AppLogAggregatorImpl.java

@@ -248,7 +248,7 @@ public class AppLogAggregatorImpl implements AppLogAggregator {
 
       } catch (IOException e1) {
         LOG.error("Cannot create writer for app " + this.applicationId
-            + ". Skip log upload this time. ");
+            + ". Skip log upload this time. ", e1);
         return;
       }
 
@@ -549,7 +549,7 @@ public class AppLogAggregatorImpl implements AppLogAggregator {
         writer.append(logKey, logValue);
       } catch (Exception e) {
         LOG.error("Couldn't upload logs for " + containerId
-            + ". Skipping this container.");
+            + ". Skipping this container.", e);
         return new HashSet<Path>();
       }
       this.uploadedFileMeta.addAll(logValue