diff --git a/solr/core/src/java/org/apache/solr/update/UpdateLog.java b/solr/core/src/java/org/apache/solr/update/UpdateLog.java
index a3e5884a6e4..74e71cb5a80 100644
--- a/solr/core/src/java/org/apache/solr/update/UpdateLog.java
+++ b/solr/core/src/java/org/apache/solr/update/UpdateLog.java
@@ -340,7 +340,9 @@ public class UpdateLog implements PluginInfoInitialized {
       } else {
         // replicate the deleteByQuery logic.  See deleteByQuery for comments.
 
-        map.clear();
+        if (map != null) map.clear();
+        if (prevMap != null) prevMap.clear();
+        if (prevMap2 != null) prevMap2.clear();
 
         try {
           RefCounted<SolrIndexSearcher> holder = uhandler.core.openNewSearcher(true, true);
@@ -400,7 +402,9 @@ public class UpdateLog implements PluginInfoInitialized {
       if ((cmd.getFlags() & UpdateCommand.BUFFERING) == 0) {
         // given that we just did a delete-by-query, we don't know what documents were
         // affected and hence we must purge our caches.
-        map.clear();
+        if (map != null) map.clear();
+        if (prevMap != null) prevMap.clear();
+        if (prevMap2 != null) prevMap2.clear();
 
         trackDeleteByQuery(cmd.getQuery(), cmd.getVersion());
 
@@ -438,7 +442,10 @@ public class UpdateLog implements PluginInfoInitialized {
         SolrException.log(log, "Error opening realtime searcher for deleteByQuery", e);
       }
 
-      map.clear();
+      if (map != null) map.clear();
+      if (prevMap != null) prevMap.clear();
+      if (prevMap2 != null) prevMap2.clear();
+
       oldDeletes.clear();
       deleteByQueries.clear();
     }
diff --git a/solr/core/src/test/org/apache/solr/search/TestStressReorder.java b/solr/core/src/test/org/apache/solr/search/TestStressReorder.java
index 2ed35786758..775fcf0bfff 100644
--- a/solr/core/src/test/org/apache/solr/search/TestStressReorder.java
+++ b/solr/core/src/test/org/apache/solr/search/TestStressReorder.java
@@ -63,7 +63,7 @@ public class TestStressReorder extends TestRTGBase {
     final int commitPercent = 5 + random().nextInt(20);
     final int softCommitPercent = 30+random().nextInt(75); // what percent of the commits are soft
     final int deletePercent = 4+random().nextInt(25);
-    final int deleteByQueryPercent = 0; // 1+random().nextInt(7);
+    final int deleteByQueryPercent = random().nextInt(8);
     final int ndocs = 5 + (random().nextBoolean() ? random().nextInt(25) : random().nextInt(200));
     int nWriteThreads = 5 + random().nextInt(25);
 
@@ -92,6 +92,9 @@ public class TestStressReorder extends TestRTGBase {
     **/
 
 
+    verbose("commitPercent",commitPercent, "softCommitPercent",softCommitPercent, "deletePercent",deletePercent, "deleteByQueryPercent",deleteByQueryPercent
+        , "ndocs",ndocs,"nWriteThreads",nWriteThreads,"percentRealtimeQuery",percentRealtimeQuery,"operations",operations, "nReadThreads",nReadThreads);
+
     initModel(ndocs);
 
     final AtomicInteger numCommitting = new AtomicInteger();