IndexGeneratorTask: Log metrics when complete

merger/src/main/java/com/metamx/druid/merger/common/index/YeOldePlumberSchool.java

@@ -81,10 +81,12 @@ public class YeOldePlumberSchool implements PlumberSchool
     // There can be only one.
     final Sink theSink = new Sink(interval, schema);
 
+    // Temporary directory to hold spilled segments.
     final File persistDir = new File(
         tmpSegmentDir, theSink.getSegment().withVersion(version).getIdentifier()
     );
 
+    // Set of spilled segments. Will be merged at the end.
     final Set<File> spilled = Sets.newHashSet();
 
     return new Plumber()

merger/src/main/java/com/metamx/druid/merger/common/task/IndexGeneratorTask.java

@@ -163,6 +163,17 @@ public class IndexGeneratorTask extends AbstractTask
     plumber.persist(firehose.commit());
     plumber.finishJob();
 
+    // Output metrics
+    log.info(
+        "Task[%s] took in %,d rows (%,d processed, %,d unparseable, %,d thrown away) and output %,d rows",
+        getId(),
+        metrics.processed() + metrics.unparseable() + metrics.thrownAway(),
+        metrics.processed(),
+        metrics.unparseable(),
+        metrics.thrownAway(),
+        metrics.rowOutput()
+    );
+
     // Done
     return TaskStatus.success(getId(), ImmutableList.copyOf(pushedSegments));
   }