Index: oak-core/src/main/java/org/apache/jackrabbit/oak/plugins/segment/file/FileStore.java
===================================================================
--- oak-core/src/main/java/org/apache/jackrabbit/oak/plugins/segment/file/FileStore.java	(revision 1599475)
+++ oak-core/src/main/java/org/apache/jackrabbit/oak/plugins/segment/file/FileStore.java	(working copy)
@@ -45,6 +45,7 @@
 import java.util.UUID;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicInteger;
 import java.util.concurrent.atomic.AtomicReference;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
@@ -51,6 +52,7 @@
 
 import org.apache.jackrabbit.oak.api.Blob;
 import org.apache.jackrabbit.oak.plugins.blob.BlobStoreBlob;
+import org.apache.jackrabbit.oak.plugins.segment.Compactor;
 import org.apache.jackrabbit.oak.plugins.segment.RecordId;
 import org.apache.jackrabbit.oak.plugins.segment.Segment;
 import org.apache.jackrabbit.oak.plugins.segment.SegmentId;
@@ -125,6 +127,17 @@
     private final AtomicBoolean cleanupNeeded = new AtomicBoolean(false);
 
     /**
+     * Flag to request segment compaction during the next flush.
+     */
+    private final AtomicBoolean compactNeeded = new AtomicBoolean(false);
+
+    /**
+     * The number of new files created at which a compaction should be
+     * triggered.
+     */
+    private int compactThreshold = 10;
+
+    /**
      * List of old tar file generations that are waiting to be removed.
      */
     private final LinkedList<File> toBeRemoved = newLinkedList();
@@ -233,6 +246,7 @@
                     timeToClose.await(1, SECONDS);
                     while (timeToClose.getCount() > 0) {
                         long start = System.nanoTime();
+                        compact();
                         try {
                             flush();
                         } catch (IOException e) {
@@ -394,6 +408,16 @@
         }
     }
 
+    public void compact() {
+        boolean compact = compactNeeded.getAndSet(false);
+        if (compact) {
+            long start = System.nanoTime();
+            Compactor.compact(this);
+            log.debug("TarMK Compaction: Completed in {}ms", MILLISECONDS
+                    .convert(System.nanoTime() - start, NANOSECONDS));
+        }
+    }
+
     public synchronized Iterable<SegmentId> getSegmentIds() {
         List<SegmentId> ids = newArrayList();
         for (UUID uuid : writer.getUUIDs()) {
@@ -567,6 +591,11 @@
                         directory,
                         String.format(FILE_NAME_FORMAT, writeNumber, "a"));
                 writer = new TarWriter(writeFile);
+
+                if (writeNumber % compactThreshold == 0) {
+                    compactNeeded.set(true);
+                }
+
             }
         } catch (IOException e) {
             throw new RuntimeException(e);
@@ -591,6 +620,7 @@
     public void gc() {
         System.gc();
         cleanupNeeded.set(true);
+        compactNeeded.set(true);
     }
 
     public Map<String, Set<UUID>> getTarReaderIndex() {