Index: oak-tarmk-standby/src/main/java/org/apache/jackrabbit/oak/plugins/segment/standby/store/StandbyStore.java
===================================================================
--- oak-tarmk-standby/src/main/java/org/apache/jackrabbit/oak/plugins/segment/standby/store/StandbyStore.java	(revision 1720171)
+++ oak-tarmk-standby/src/main/java/org/apache/jackrabbit/oak/plugins/segment/standby/store/StandbyStore.java	(working copy)
@@ -16,6 +16,7 @@
  */
 package org.apache.jackrabbit.oak.plugins.segment.standby.store;
 
+import static com.google.common.collect.Sets.newHashSet;
 import static org.apache.jackrabbit.oak.commons.IOUtils.humanReadableByteCount;
 
 import java.io.ByteArrayOutputStream;
@@ -88,8 +89,15 @@
         long maxWeight = 0;
         long maxKeys = 0;
 
+        Set<SegmentId> visited = newHashSet();
+
         while (!ids.isEmpty()) {
             SegmentId id = ids.remove();
+
+            if (!visited.add(id)) {
+                continue;
+            }
+
             if (!persisted.contains(id) && !delegate.containsSegment(id)) {
                 Segment s;
                 boolean logRefs = true;