diff --git a/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/ram/RamTable.java b/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/ram/RamTable.java
index 1cbe73afc4..c83d92980f 100644
--- a/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/ram/RamTable.java
+++ b/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/ram/RamTable.java
@@ -37,12 +37,6 @@
 import java.util.concurrent.ExecutorService;
 
 import org.apache.commons.io.FileUtils;
-import org.apache.tinkerpop.gremlin.structure.Edge;
-import org.apache.tinkerpop.gremlin.structure.Vertex;
-import org.apache.tinkerpop.gremlin.structure.util.CloseableIterator;
-import org.apache.tinkerpop.gremlin.util.iterator.IteratorUtils;
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.HugeException;
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.backend.id.Id;
@@ -62,6 +56,11 @@
 import org.apache.hugegraph.type.define.HugeKeys;
 import org.apache.hugegraph.util.Consumers;
 import org.apache.hugegraph.util.Log;
+import org.apache.tinkerpop.gremlin.structure.Edge;
+import org.apache.tinkerpop.gremlin.structure.Vertex;
+import org.apache.tinkerpop.gremlin.structure.util.CloseableIterator;
+import org.apache.tinkerpop.gremlin.util.iterator.IteratorUtils;
+import org.slf4j.Logger;
 
 public final class RamTable {
 
@@ -200,7 +199,6 @@ private void loadFromDB() throws Exception {
         Id lastId = IdGenerator.ZERO;
         while (vertices.hasNext()) {
             Id vertex = (Id) vertices.next().id();
-            LOG.info("scan from hbase {} loadfromDB", vertex);
             if (vertex.compareTo(lastId) < 0) {
                 throw new HugeException("The ramtable feature is not " +
                                         "supported by %s backend",
@@ -496,6 +494,11 @@ public LoadTraverser() {
         @Override
         public void close() throws Exception {
             if (this.executor != null) {
+                for (int i = 0; i < Consumers.THREADS; i++) {
+                    this.executor.execute(() -> {
+                        this.graph.tx().commit();
+                    });
+                }
                 this.executor.shutdown();
             }
         }
diff --git a/hugegraph-test/src/main/java/org/apache/hugegraph/core/BaseCoreTest.java b/hugegraph-test/src/main/java/org/apache/hugegraph/core/BaseCoreTest.java
index ab92ac4178..894b667450 100644
--- a/hugegraph-test/src/main/java/org/apache/hugegraph/core/BaseCoreTest.java
+++ b/hugegraph-test/src/main/java/org/apache/hugegraph/core/BaseCoreTest.java
@@ -21,27 +21,72 @@
 
 import java.util.Random;
 
-import org.apache.tinkerpop.gremlin.structure.Edge;
-import org.apache.tinkerpop.gremlin.structure.Vertex;
-import org.junit.After;
-import org.junit.Before;
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.HugeGraphParams;
+import org.apache.hugegraph.backend.id.IdGenerator;
 import org.apache.hugegraph.backend.store.BackendFeatures;
+import org.apache.hugegraph.dist.RegisterUtil;
 import org.apache.hugegraph.schema.SchemaManager;
+import org.apache.hugegraph.testutil.Utils;
 import org.apache.hugegraph.testutil.Whitebox;
+import org.apache.hugegraph.type.define.NodeRole;
 import org.apache.hugegraph.util.Log;
+import org.apache.tinkerpop.gremlin.structure.Edge;
+import org.apache.tinkerpop.gremlin.structure.Vertex;
+import org.junit.After;
+import org.junit.AfterClass;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.slf4j.Logger;
 
 public class BaseCoreTest {
 
     protected static final Logger LOG = Log.logger(BaseCoreTest.class);
 
     protected static final int TX_BATCH = 100;
+    private static boolean registered = false;
+    private static HugeGraph graph = null;
 
-    public HugeGraph graph() {
-        return CoreTestSuite.graph();
+    public static HugeGraph graph() {
+        Assert.assertNotNull(graph);
+        //Assert.assertFalse(graph.closed());
+        return graph;
+    }
+
+    @BeforeClass
+    public static void initEnv() {
+        if (registered) {
+            return;
+        }
+        RegisterUtil.registerBackends();
+        registered = true;
+    }
+
+    @BeforeClass
+    public static void init() {
+        graph = Utils.open();
+        graph.clearBackend();
+        graph.initBackend();
+        graph.serverStarted(IdGenerator.of("server1"), NodeRole.MASTER);
+    }
+
+    @AfterClass
+    public static void clear() {
+        if (graph == null) {
+            return;
+        }
+
+        try {
+            graph.clearBackend();
+        } finally {
+            try {
+                graph.close();
+            } catch (Throwable e) {
+                LOG.error("Error when close()", e);
+            }
+            graph = null;
+        }
     }
 
     @Before
diff --git a/hugegraph-test/src/main/java/org/apache/hugegraph/core/CoreTestSuite.java b/hugegraph-test/src/main/java/org/apache/hugegraph/core/CoreTestSuite.java
index 4d60e86519..83c566dc1b 100644
--- a/hugegraph-test/src/main/java/org/apache/hugegraph/core/CoreTestSuite.java
+++ b/hugegraph-test/src/main/java/org/apache/hugegraph/core/CoreTestSuite.java
@@ -19,21 +19,10 @@
 
 package org.apache.hugegraph.core;
 
-import org.apache.hugegraph.testutil.Utils;
-import org.junit.AfterClass;
-import org.junit.Assert;
-import org.junit.BeforeClass;
-import org.junit.runner.RunWith;
-import org.junit.runners.Suite;
-import org.slf4j.Logger;
-
-import org.apache.hugegraph.HugeGraph;
-import org.apache.hugegraph.backend.id.IdGenerator;
 import org.apache.hugegraph.core.PropertyCoreTest.EdgePropertyCoreTest;
 import org.apache.hugegraph.core.PropertyCoreTest.VertexPropertyCoreTest;
-import org.apache.hugegraph.dist.RegisterUtil;
-import org.apache.hugegraph.type.define.NodeRole;
-import org.apache.hugegraph.util.Log;
+import org.junit.runner.RunWith;
+import org.junit.runners.Suite;
 
 @RunWith(Suite.class)
 @Suite.SuiteClasses({
@@ -54,44 +43,4 @@
 })
 public class CoreTestSuite {
 
-    private static final Logger LOG = Log.logger(CoreTestSuite.class);
-
-    private static HugeGraph graph = null;
-
-    @BeforeClass
-    public static void initEnv() {
-        RegisterUtil.registerBackends();
-    }
-
-    @BeforeClass
-    public static void init() {
-        graph = Utils.open();
-        graph.clearBackend();
-        graph.initBackend();
-        graph.serverStarted(IdGenerator.of("server1"), NodeRole.MASTER);
-    }
-
-    @AfterClass
-    public static void clear() {
-        if (graph == null) {
-            return;
-        }
-
-        try {
-            graph.clearBackend();
-        } finally {
-            try {
-                graph.close();
-            } catch (Throwable e) {
-                LOG.error("Error when close()", e);
-            }
-            graph = null;
-        }
-    }
-
-    protected static HugeGraph graph() {
-        Assert.assertNotNull(graph);
-        //Assert.assertFalse(graph.closed());
-        return graph;
-    }
 }
diff --git a/hugegraph-test/src/main/java/org/apache/hugegraph/core/MultiGraphsTest.java b/hugegraph-test/src/main/java/org/apache/hugegraph/core/MultiGraphsTest.java
index 7963c9366d..cef98c3977 100644
--- a/hugegraph-test/src/main/java/org/apache/hugegraph/core/MultiGraphsTest.java
+++ b/hugegraph-test/src/main/java/org/apache/hugegraph/core/MultiGraphsTest.java
@@ -27,13 +27,6 @@
 import org.apache.commons.configuration2.BaseConfiguration;
 import org.apache.commons.configuration2.Configuration;
 import org.apache.commons.configuration2.PropertiesConfiguration;
-import org.apache.tinkerpop.gremlin.structure.T;
-import org.apache.tinkerpop.gremlin.structure.Vertex;
-import org.apache.tinkerpop.gremlin.structure.util.GraphFactory;
-import org.apache.hugegraph.testutil.Utils;
-import org.junit.Test;
-import org.rocksdb.RocksDBException;
-
 import org.apache.hugegraph.HugeException;
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.backend.id.IdGenerator;
@@ -48,10 +41,17 @@
 import org.apache.hugegraph.schema.SchemaManager;
 import org.apache.hugegraph.schema.VertexLabel;
 import org.apache.hugegraph.testutil.Assert;
+import org.apache.hugegraph.testutil.Utils;
 import org.apache.hugegraph.type.define.NodeRole;
+import org.apache.tinkerpop.gremlin.structure.T;
+import org.apache.tinkerpop.gremlin.structure.Vertex;
+import org.apache.tinkerpop.gremlin.structure.util.GraphFactory;
+import org.junit.Test;
+import org.rocksdb.RocksDBException;
+
 import com.google.common.collect.ImmutableList;
 
-public class MultiGraphsTest {
+public class MultiGraphsTest extends BaseCoreTest {
 
     private static final String NAME48 =
             "g12345678901234567890123456789012345678901234567";