1) Fix DatabaseSegmentManager so that Unit Test passes

server/src/main/java/com/metamx/druid/db/DatabaseSegmentManager.java

@@ -103,10 +103,11 @@ public class DatabaseSegmentManager
         return;
       }
 
+      final Duration delay = config.get().getPollDuration().toStandardDuration();
       ScheduledExecutors.scheduleWithFixedDelay(
           exec,
-          new Duration(0),
-          config.get().getPollDuration().toStandardDuration(),
+          delay,
+          delay,
           new Runnable()
           {
             @Override
@@ -131,6 +132,7 @@ public class DatabaseSegmentManager
 
       started = false;
       dataSources.set(new ConcurrentHashMap<String, DruidDataSource>());
+      exec.shutdownNow();
     }
   }
 

server/src/test/java/com/metamx/druid/db/DatabaseSegmentManagerTest.java

@@ -94,10 +94,7 @@ public class DatabaseSegmentManagerTest
                    + "\"twitterstream_2012-01-05T00:00:00.000Z_2012-01-06T00:00:00.000Z_2012-01-06T22:19:12.565Z\"}"
     );
 
-    testRows = Arrays.<Map<String, Object>>asList(
-        map1,
-        map2
-    );
+    testRows = Arrays.<Map<String, Object>>asList(map1, map2);
   }
 
   @After
@@ -114,5 +111,6 @@ public class DatabaseSegmentManagerTest
 
     manager.start();
     manager.poll();
+    manager.stop();
   }
 }