diff --git a/realtime/src/main/java/com/metamx/druid/realtime/plumber/RealtimePlumberSchool.java b/realtime/src/main/java/com/metamx/druid/realtime/plumber/RealtimePlumberSchool.java
index 21a28062537..849cf8ea1a9 100644
--- a/realtime/src/main/java/com/metamx/druid/realtime/plumber/RealtimePlumberSchool.java
+++ b/realtime/src/main/java/com/metamx/druid/realtime/plumber/RealtimePlumberSchool.java
@@ -70,6 +70,7 @@ import org.joda.time.Period;
 
 import javax.annotation.Nullable;
 import java.io.File;
+import java.io.FilenameFilter;
 import java.io.IOException;
 import java.util.Arrays;
 import java.util.Comparator;
@@ -377,7 +378,14 @@ public class RealtimePlumberSchool implements PlumberSchool
         for (File sinkDir : computeBaseDir(schema).listFiles()) {
           Interval sinkInterval = new Interval(sinkDir.getName().replace("_", "/"));
 
-          final File[] sinkFiles = sinkDir.listFiles();
+          //final File[] sinkFiles = sinkDir.listFiles();
+          // To avoid reading and listing of "merged" dir
+          final File[] sinkFiles = sinkDir.listFiles(new FilenameFilter() {  		
+        			@Override
+        			public boolean accept(File dir, String fileName) {				
+        				return !(Ints.tryParse(fileName) == null);
+        			}
+        		});
           Arrays.sort(
               sinkFiles,
               new Comparator<File>()
@@ -400,6 +408,15 @@ public class RealtimePlumberSchool implements PlumberSchool
             List<FireHydrant> hydrants = Lists.newArrayList();
             for (File segmentDir : sinkFiles) {
               log.info("Loading previously persisted segment at [%s]", segmentDir);
+              
+              // Although this has been tackled at start of this method.
+              // Just a doubly-check added to skip "merged" dir. from being added to hydrants 
+              // If 100% sure that this is not needed, this check can be removed.
+              if(Ints.tryParse(segmentDir.getName()) == null)
+              {
+                continue;
+              }
+              
               hydrants.add(
                   new FireHydrant(
                       new QueryableIndexSegment(null, IndexIO.loadIndex(segmentDir)),