TEZ-4568: ProfileServlet: add html to output formats

tez-common/src/main/java/org/apache/tez/common/web/ProfileServlet.java

@@ -50,19 +50,19 @@
  * //  -m method         fully qualified method name: 'ClassName.methodName'
  * //  -t                profile different threads separately
  * //  -s                simple class names instead of FQN
- * //  -o fmt[,fmt...]   output format: summary|traces|flat|collapsed|svg|tree|jfr
+ * //  -o fmt[,fmt...]   output format: summary|traces|flat|collapsed|svg|tree|jfr|html
  * //  --width px        SVG width pixels (integer)
  * //  --height px       SVG frame height pixels (integer)
  * //  --minwidth px     skip frames smaller than px (double)
  * //  --reverse         generate stack-reversed FlameGraph / Call tree
  * Example:
- * - To collect 30 second CPU profile of current process (returns FlameGraph svg)
+ * - To collect 30 second CPU profile of current process (returns FlameGraph html)
  * {@literal curl "http://localhost:10002/prof"}
  * - To collect 1 minute CPU profile of current process and output in tree format (html)
  * {@literal curl  "http://localhost:10002/prof?output=tree&duration=60"}
- * - To collect 30 second heap allocation profile of current process (returns FlameGraph svg)
+ * - To collect 30 second heap allocation profile of current process (returns FlameGraph html)
  * {@literal curl "http://localhost:10002/prof?event=alloc"}
- * - To collect lock contention profile of current process (returns FlameGraph svg)
+ * - To collect lock contention profile of current process (returns FlameGraph html)
  * {@literal curl "http://localhost:10002/prof?event=lock"}
  * Following event types are supported (default is 'cpu') (NOTE: not all OS'es support all events)
  * // Perf events:
@@ -140,7 +140,7 @@ public static Event fromInternalName(final String name) {
   }
 
   enum Output {
-    SUMMARY, TRACES, FLAT, COLLAPSED, SVG, TREE, JFR
+    SUMMARY, TRACES, FLAT, COLLAPSED, SVG, TREE, JFR, HTML
   }
 
   private final Lock profilerLock = new ReentrantLock();
@@ -349,11 +349,11 @@ private Output getOutput(final HttpServletRequest req) {
       try {
         return Output.valueOf(outputArg.trim().toUpperCase());
       } catch (IllegalArgumentException e) {
-        LOG.warn("Output format value is invalid, returning with default SVG");
-        return Output.SVG;
+        LOG.warn("Output format value is invalid, returning with default HTML");
+        return Output.HTML;
       }
     }
-    return Output.SVG;
+    return Output.HTML;
   }
 
   private void setResponseHeader(final HttpServletResponse response) {