https://issues.apache.org/jira/browse/AMQ-4485 - leveldb version - shows the need to flag async adds so they can get suppressed as duplicates \(and not go to the dlq\) when the cursor order is out of sync on cache full

activemq-leveldb-store/src/main/scala/org/apache/activemq/leveldb/DBManager.scala

@@ -335,6 +335,7 @@ class DelayableUOW(val manager:DBManager) extends BaseRetained {
        id.setFutureOrSequenceLong(queueSeq)
     } else {
       id.setFutureOrSequenceLong(countDownFuture)
+      message.setRecievedByDFBridge(true)
       countDownFuture.id = id
     }
 

activemq-unit-tests/src/test/java/org/apache/activemq/bugs/AMQ4485LowLimitLevelDBTest.java

@@ -0,0 +1,38 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.activemq.bugs;
+
+import java.io.File;
+import org.apache.activemq.broker.BrokerService;
+import org.apache.activemq.leveldb.LevelDBStore;
+
+public class AMQ4485LowLimitLevelDBTest extends AMQ4485LowLimitTest {
+
+    public AMQ4485LowLimitLevelDBTest() {
+        super();
+        numBrokers = 2;
+    }
+
+    protected BrokerService createBroker(int brokerid, boolean addToNetwork) throws Exception {
+        BrokerService broker = super.createBroker(brokerid, addToNetwork);
+
+        LevelDBStore levelDBStore = new LevelDBStore();
+        levelDBStore.setDirectory(new File(broker.getBrokerDataDirectory(),"levelDB"));
+        broker.setPersistenceAdapter(levelDBStore);
+        return broker;
+    }
+}

activemq-unit-tests/src/test/java/org/apache/activemq/bugs/AMQ4485LowLimitTest.java

@@ -64,7 +64,7 @@ public class AMQ4485LowLimitTest extends JmsMultipleBrokersTestSupport {
     static final String payload = new String(new byte[10 * 1024]);
     private static final Logger LOG = LoggerFactory.getLogger(AMQ4485LowLimitTest.class);
     final int portBase = 61600;
-    final int numBrokers = 8;
+    int numBrokers = 8;
     final int numProducers = 30;
     final int numMessages = 1000;
     final int consumerSleepTime = 40;