diff --git a/common/network-common/pom.xml b/common/network-common/pom.xml
index ef7f9824e13c1..d2edbd7690a17 100644
--- a/common/network-common/pom.xml
+++ b/common/network-common/pom.xml
@@ -151,7 +151,6 @@
     <dependency>
       <groupId>org.apache.spark</groupId>
       <artifactId>spark-tags_${scala.binary.version}</artifactId>
-      <scope>test</scope>
    </dependency>
 
     <!--
diff --git a/common/network-common/src/main/java/org/apache/spark/network/shuffledb/DB.java b/common/network-common/src/main/java/org/apache/spark/network/shuffledb/DB.java
index 3b2060cb74a47..0ac0c9e8fe4d1 100644
--- a/common/network-common/src/main/java/org/apache/spark/network/shuffledb/DB.java
+++ b/common/network-common/src/main/java/org/apache/spark/network/shuffledb/DB.java
@@ -19,10 +19,13 @@
 
 import java.io.Closeable;
 
+import org.apache.spark.annotation.Private;
+
 /**
  * The local KV storage used to persist the shuffle state,
  * the implementations may include LevelDB, RocksDB, etc.
  */
+@Private
 public interface DB extends Closeable {
     /**
      * Set the DB entry for "key" to "value".
diff --git a/common/network-common/src/main/java/org/apache/spark/network/shuffledb/DBIterator.java b/common/network-common/src/main/java/org/apache/spark/network/shuffledb/DBIterator.java
index 4607faa070a9d..1428f6fac7b4f 100644
--- a/common/network-common/src/main/java/org/apache/spark/network/shuffledb/DBIterator.java
+++ b/common/network-common/src/main/java/org/apache/spark/network/shuffledb/DBIterator.java
@@ -21,6 +21,9 @@
 import java.util.Iterator;
 import java.util.Map;
 
+import org.apache.spark.annotation.Private;
+
+@Private
 public interface DBIterator extends Iterator<Map.Entry<byte[], byte[]>>, Closeable {
 
     /**
diff --git a/common/network-common/src/main/java/org/apache/spark/network/shuffledb/LevelDBIterator.java b/common/network-common/src/main/java/org/apache/spark/network/shuffledb/LevelDBIterator.java
index 7f80928e461fc..5796e34a6f05e 100644
--- a/common/network-common/src/main/java/org/apache/spark/network/shuffledb/LevelDBIterator.java
+++ b/common/network-common/src/main/java/org/apache/spark/network/shuffledb/LevelDBIterator.java
@@ -78,11 +78,6 @@ public void seek(byte[] key) {
         it.seek(key);
     }
 
-    @Override
-    public void remove() {
-      throw new UnsupportedOperationException();
-    }
-
     private Map.Entry<byte[], byte[]> loadNext() {
         boolean hasNext = it.hasNext();
         if (!hasNext) {
diff --git a/common/network-shuffle/src/main/java/org/apache/spark/network/shuffle/ExternalShuffleBlockResolver.java b/common/network-shuffle/src/main/java/org/apache/spark/network/shuffle/ExternalShuffleBlockResolver.java
index ff49eb6244c8a..6bca19a2511ac 100644
--- a/common/network-shuffle/src/main/java/org/apache/spark/network/shuffle/ExternalShuffleBlockResolver.java
+++ b/common/network-shuffle/src/main/java/org/apache/spark/network/shuffle/ExternalShuffleBlockResolver.java
@@ -125,16 +125,13 @@ public ShuffleIndexInformation load(String filePath) throws IOException {
       .weigher((Weigher<String, ShuffleIndexInformation>)
         (filePath, indexInfo) -> indexInfo.getRetainedMemorySize())
       .build(indexCacheLoader);
-    DBBackend dbBackend = null;
-    if (registeredExecutorFile != null) {
-      String dbBackendName =
-        conf.get(Constants.SHUFFLE_SERVICE_DB_BACKEND, DBBackend.LEVELDB.name());
-      dbBackend = DBBackend.byName(dbBackendName);
-      logger.info("Configured {} as {} and actually used value {}",
-        Constants.SHUFFLE_SERVICE_DB_BACKEND, dbBackendName, dbBackend);
-    }
+    String dbBackendName =
+      conf.get(Constants.SHUFFLE_SERVICE_DB_BACKEND, DBBackend.LEVELDB.name());
+    DBBackend dbBackend = DBBackend.byName(dbBackendName);
     db = DBProvider.initDB(dbBackend, this.registeredExecutorFile, CURRENT_VERSION, mapper);
     if (db != null) {
+      logger.info("Use {} as the implementation of {}",
+        dbBackend, Constants.SHUFFLE_SERVICE_DB_BACKEND);
       executors = reloadRegisteredExecutors(db);
     } else {
       executors = Maps.newConcurrentMap();
diff --git a/common/network-shuffle/src/main/java/org/apache/spark/network/shuffle/RemoteBlockPushResolver.java b/common/network-shuffle/src/main/java/org/apache/spark/network/shuffle/RemoteBlockPushResolver.java
index 103b2f0e3baa0..8d28fc43ac155 100644
--- a/common/network-shuffle/src/main/java/org/apache/spark/network/shuffle/RemoteBlockPushResolver.java
+++ b/common/network-shuffle/src/main/java/org/apache/spark/network/shuffle/RemoteBlockPushResolver.java
@@ -156,16 +156,13 @@ public ShuffleIndexInformation load(String filePath) throws IOException {
         (filePath, indexInfo) -> indexInfo.getRetainedMemorySize())
       .build(indexCacheLoader);
     this.recoveryFile = recoveryFile;
-    DBBackend dbBackend = null;
-    if (recoveryFile != null) {
-      String dbBackendName =
-        conf.get(Constants.SHUFFLE_SERVICE_DB_BACKEND, DBBackend.LEVELDB.name());
-      dbBackend = DBBackend.byName(dbBackendName);
-      logger.info("Configured {} as {} and actually used value {}",
-        Constants.SHUFFLE_SERVICE_DB_BACKEND, dbBackendName, dbBackend);
-    }
+    String dbBackendName =
+      conf.get(Constants.SHUFFLE_SERVICE_DB_BACKEND, DBBackend.LEVELDB.name());
+    DBBackend dbBackend = DBBackend.byName(dbBackendName);
     db = DBProvider.initDB(dbBackend, this.recoveryFile, CURRENT_VERSION, mapper);
     if (db != null) {
+      logger.info("Use {} as the implementation of {}",
+        dbBackend, Constants.SHUFFLE_SERVICE_DB_BACKEND);
       reloadAndCleanUpAppShuffleInfo(db);
     }
   }
diff --git a/common/network-yarn/src/main/java/org/apache/spark/network/yarn/YarnShuffleService.java b/common/network-yarn/src/main/java/org/apache/spark/network/yarn/YarnShuffleService.java
index 1e2ff89480895..58f6b6500f697 100644
--- a/common/network-yarn/src/main/java/org/apache/spark/network/yarn/YarnShuffleService.java
+++ b/common/network-yarn/src/main/java/org/apache/spark/network/yarn/YarnShuffleService.java
@@ -241,8 +241,8 @@ protected void serviceInit(Configuration externalConf) throws Exception {
       String dbBackendName = _conf.get(Constants.SHUFFLE_SERVICE_DB_BACKEND,
         DBBackend.LEVELDB.name());
       dbBackend = DBBackend.byName(dbBackendName);
-      logger.info("Configured {} as {} and actually used value {}",
-        Constants.SHUFFLE_SERVICE_DB_BACKEND, dbBackendName, dbBackend);
+      logger.info("Use {} as the implementation of {}",
+        dbBackend, Constants.SHUFFLE_SERVICE_DB_BACKEND);
     }
 
     try {
diff --git a/core/src/main/scala/org/apache/spark/deploy/ExternalShuffleService.scala b/core/src/main/scala/org/apache/spark/deploy/ExternalShuffleService.scala
index a139f4c1708eb..22b138e5d9881 100644
--- a/core/src/main/scala/org/apache/spark/deploy/ExternalShuffleService.scala
+++ b/core/src/main/scala/org/apache/spark/deploy/ExternalShuffleService.scala
@@ -81,11 +81,11 @@ class ExternalShuffleService(sparkConf: SparkConf, securityManager: SecurityMana
   protected def newShuffleBlockHandler(conf: TransportConf): ExternalBlockHandler = {
     if (sparkConf.get(config.SHUFFLE_SERVICE_DB_ENABLED) && enabled) {
       val shuffleDBName = sparkConf.get(config.SHUFFLE_SERVICE_DB_BACKEND)
-      val dBBackend = DBBackend.byName(shuffleDBName)
-      logInfo(s"Configured ${config.SHUFFLE_SERVICE_DB_BACKEND.key} as $shuffleDBName " +
-        s"and actually used value ${dBBackend.name()} ")
+      val dbBackend = DBBackend.byName(shuffleDBName)
+      logInfo(s"Use ${dbBackend.name()} as the implementation of " +
+        s"${config.SHUFFLE_SERVICE_DB_BACKEND.key}")
       new ExternalBlockHandler(conf,
-        findRegisteredExecutorsDBFile(dBBackend.fileName(registeredExecutorsDB)))
+        findRegisteredExecutorsDBFile(dbBackend.fileName(registeredExecutorsDB)))
     } else {
       new ExternalBlockHandler(conf, null)
     }
diff --git a/resource-managers/yarn/src/test/scala/org/apache/spark/deploy/yarn/YarnShuffleIntegrationSuite.scala b/resource-managers/yarn/src/test/scala/org/apache/spark/deploy/yarn/YarnShuffleIntegrationSuite.scala
index fb9d3cc520cfa..70c77a55c8698 100644
--- a/resource-managers/yarn/src/test/scala/org/apache/spark/deploy/yarn/YarnShuffleIntegrationSuite.scala
+++ b/resource-managers/yarn/src/test/scala/org/apache/spark/deploy/yarn/YarnShuffleIntegrationSuite.scala
@@ -162,8 +162,8 @@ private object YarnExternalShuffleDriver extends Logging with Matchers {
       if (registeredExecFile != null && execStateCopy != null) {
         val dbBackendName = conf.get(SHUFFLE_SERVICE_DB_BACKEND.key)
         val dbBackend = DBBackend.byName(dbBackendName)
-        logWarning(s"Configured ${SHUFFLE_SERVICE_DB_BACKEND.key} as $dbBackendName " +
-          s"and actually used value ${dbBackend.name()}")
+        logWarning(s"Use ${dbBackend.name()} as the implementation of " +
+          s"${SHUFFLE_SERVICE_DB_BACKEND.key}")
         FileUtils.copyDirectory(registeredExecFile, execStateCopy)
         assert(!ShuffleTestAccessor
           .reloadRegisteredExecutors(dbBackend, execStateCopy).isEmpty)
diff --git a/resource-managers/yarn/src/test/scala/org/apache/spark/network/yarn/YarnShuffleServiceSuite.scala b/resource-managers/yarn/src/test/scala/org/apache/spark/network/yarn/YarnShuffleServiceSuite.scala
index 9a24ab8adff6a..09563e88e8a9b 100644
--- a/resource-managers/yarn/src/test/scala/org/apache/spark/network/yarn/YarnShuffleServiceSuite.scala
+++ b/resource-managers/yarn/src/test/scala/org/apache/spark/network/yarn/YarnShuffleServiceSuite.scala
@@ -45,7 +45,7 @@ import org.apache.spark.SecurityManager
 import org.apache.spark.SparkFunSuite
 import org.apache.spark.internal.config._
 import org.apache.spark.network.server.BlockPushNonFatalFailure
-import org.apache.spark.network.shuffle.{MergedShuffleFileManager, NoOpMergedShuffleFileManager, RemoteBlockPushResolver, ShuffleTestAccessor}
+import org.apache.spark.network.shuffle.{Constants, MergedShuffleFileManager, NoOpMergedShuffleFileManager, RemoteBlockPushResolver, ShuffleTestAccessor}
 import org.apache.spark.network.shuffle.RemoteBlockPushResolver._
 import org.apache.spark.network.shuffle.protocol.ExecutorShuffleInfo
 import org.apache.spark.network.shuffledb.DBBackend
@@ -1068,6 +1068,8 @@ abstract class YarnShuffleServiceSuite extends SparkFunSuite with Matchers {
 
   test("create remote block push resolver instance") {
     val mockConf = mock(classOf[TransportConf])
+    when(mockConf.get(Constants.SHUFFLE_SERVICE_DB_BACKEND, DBBackend.LEVELDB.name()))
+      .thenReturn(shuffleDBBackend().name())
     when(mockConf.mergedShuffleFileManagerImpl).thenReturn(
       "org.apache.spark.network.shuffle.RemoteBlockPushResolver")
     val mergeMgr = YarnShuffleService.newMergedShuffleFileManagerInstance(mockConf, null)