YARN-3584. Fixed attempt diagnostics format shown on the UI. Contributed by nijel

(cherry picked from commit b88700dcd0b9aa47662009241dfb83bc4446548d)

hadoop-yarn-project/CHANGES.txt

@@ -285,6 +285,9 @@ Release 2.8.0 - UNRELEASED
     YARN-3577. Misspelling of threshold in log4j.properties for tests.
     (Brahma Reddy Battula via aajisaka)
 
+    YARN-3584. Fixed attempt diagnostics format shown on the UI. (nijel via
+    jianhe)
+
 Release 2.7.1 - UNRELEASED
 
   INCOMPATIBLE CHANGES

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/rmapp/attempt/RMAppAttemptImpl.java

@@ -1455,14 +1455,14 @@ public class RMAppAttemptImpl implements RMAppAttempt, Recoverable {
       finishEvent.getApplicationAttemptId()).append(
       " exited with ").append(" exitCode: ").append(status.getExitStatus()).
       append("\n");
+    diagnosticsBuilder.append("Failing this attempt.").append("Diagnostics: ")
+        .append(status.getDiagnostics());
     if (this.getTrackingUrl() != null) {
       diagnosticsBuilder.append("For more detailed output,").append(
-        " check application tracking page:").append(
+        " check application tracking page: ").append(
         this.getTrackingUrl()).append(
-        "Then, click on links to logs of each attempt.\n");
+        " Then, click on links to logs of each attempt.\n");
     }
-    diagnosticsBuilder.append("Diagnostics: ").append(status.getDiagnostics())
-        .append("Failing this attempt");
     return diagnosticsBuilder.toString();
   }