diff --git a/kyuubi-common/src/main/scala/org/apache/kyuubi/KyuubiException.scala b/kyuubi-common/src/main/scala/org/apache/kyuubi/KyuubiException.scala
index e1f65fb7a..d167ed8f2 100644
--- a/kyuubi-common/src/main/scala/org/apache/kyuubi/KyuubiException.scala
+++ b/kyuubi-common/src/main/scala/org/apache/kyuubi/KyuubiException.scala
@@ -20,5 +20,4 @@ package org.apache.kyuubi
 class KyuubiException(message: String, cause: Throwable) extends Exception(message, cause) {
 
   def this(message: String) = this(message, null)
-  def this(cause: Throwable) = this(cause.getMessage, cause)
 }
diff --git a/kyuubi-common/src/main/scala/org/apache/kyuubi/service/Service.scala b/kyuubi-common/src/main/scala/org/apache/kyuubi/service/Service.scala
index d0c31066e..683969414 100644
--- a/kyuubi-common/src/main/scala/org/apache/kyuubi/service/Service.scala
+++ b/kyuubi-common/src/main/scala/org/apache/kyuubi/service/Service.scala
@@ -24,7 +24,7 @@ trait Service {
   /**
    * Initialize the service.
    *
-   * The transition must be from [[LATENT]]to [[INITIALIZED]] unless the
+   * The transition must be from [[LATENT]] to [[INITIALIZED]] unless the
    * operation failed and an exception was raised.
    *
    * @param conf the configuration of the service
diff --git a/kyuubi-common/src/test/scala/org/apache/kyuubi/KyuubiSQLExceptionSuite.scala b/kyuubi-common/src/test/scala/org/apache/kyuubi/KyuubiSQLExceptionSuite.scala
index cc91b1f61..658a55fe9 100644
--- a/kyuubi-common/src/test/scala/org/apache/kyuubi/KyuubiSQLExceptionSuite.scala
+++ b/kyuubi-common/src/test/scala/org/apache/kyuubi/KyuubiSQLExceptionSuite.scala
@@ -26,7 +26,7 @@ class KyuubiSQLExceptionSuite extends KyuubiFunSuite {
     val msg1 = "this is just a dummy msg 1"
     val msg2 = "this is just a dummy msg 2"
 
-    val e0 = new RuntimeException(msg0)
+    val e0 = new KyuubiException(msg0)
     val e1 = new KyuubiException(msg1, e0)
     val e2 = new KyuubiSQLException(msg2, e1)
     assert(e2.toTStatus === KyuubiSQLException.toTStatus(e2))
diff --git a/kyuubi-common/src/test/scala/org/apache/kyuubi/cli/HandleIdentifierSuite.scala b/kyuubi-common/src/test/scala/org/apache/kyuubi/cli/HandleIdentifierSuite.scala
index 1507a710d..beaccae4d 100644
--- a/kyuubi-common/src/test/scala/org/apache/kyuubi/cli/HandleIdentifierSuite.scala
+++ b/kyuubi-common/src/test/scala/org/apache/kyuubi/cli/HandleIdentifierSuite.scala
@@ -37,5 +37,8 @@ class HandleIdentifierSuite extends KyuubiFunSuite {
     val id4 = HandleIdentifier()
     assert(id4 !== id1)
     assert(id4 !== new Integer(1))
+
+    val id5 = HandleIdentifier(id1.publicId, id1.publicId)
+    assert(id1 !== id5, "no matched secret id")
   }
 }
diff --git a/kyuubi-ha/src/main/scala/org/apache/kyuubi/ha/client/ServiceDiscovery.scala b/kyuubi-ha/src/main/scala/org/apache/kyuubi/ha/client/ServiceDiscovery.scala
index 04bd8b613..7226ccd34 100644
--- a/kyuubi-ha/src/main/scala/org/apache/kyuubi/ha/client/ServiceDiscovery.scala
+++ b/kyuubi-ha/src/main/scala/org/apache/kyuubi/ha/client/ServiceDiscovery.scala
@@ -98,7 +98,7 @@ class ServiceDiscovery private (
         .forPath(s"/$namespace")
     } catch {
       case _: NodeExistsException =>  // do nothing
-      case e: KeeperException => throw new KyuubiException(e)
+      case e: KeeperException => throw new KyuubiException(s"Failed to create namespace '/$namespace'", e)
     }
     super.initialize(conf)
   }
diff --git a/kyuubi-server/src/test/scala/yaooqinn/kyuubi/cli/HandleIdentifierSuite.scala b/kyuubi-server/src/test/scala/yaooqinn/kyuubi/cli/HandleIdentifierSuite.scala
deleted file mode 100644
index 0cd733b7d..000000000
--- a/kyuubi-server/src/test/scala/yaooqinn/kyuubi/cli/HandleIdentifierSuite.scala
+++ /dev/null
@@ -1,55 +0,0 @@
-/*
- * 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 yaooqinn.kyuubi.cli
-
-import java.nio.ByteBuffer
-import java.util.UUID
-
-import org.apache.hive.service.cli.thrift.THandleIdentifier
-import org.apache.spark.SparkFunSuite
-
-class HandleIdentifierSuite extends SparkFunSuite {
-
-  test("handle identifier instantiating and equality") {
-    // default constructor
-    val pid = UUID.randomUUID()
-    val sid = UUID.randomUUID()
-    val handleId1 = new HandleIdentifier(pid, sid)
-    assert(pid === handleId1.getPublicId)
-    assert(sid === handleId1.getSecretId)
-    assert(handleId1.toTHandleIdentifier.bufferForGuid() !== null)
-    assert(handleId1.toTHandleIdentifier.bufferForSecret() !== null)
-    assert(handleId1.toString === pid.toString)
-
-    // constructor without any parameter
-    val handleId2 = new HandleIdentifier()
-    assert(pid !== handleId2.getPublicId)
-    assert(sid !== handleId2.getSecretId)
-    assert(handleId1 !== handleId2)
-    assert(handleId1.toTHandleIdentifier !== handleId2.toTHandleIdentifier)
-
-    // constructor with THandleIdentifier
-    val handleId3 = new HandleIdentifier(handleId1.toTHandleIdentifier)
-    assert(handleId1 === handleId3)
-
-    val tHandleId = new THandleIdentifier(ByteBuffer.allocate(16), ByteBuffer.allocate(16))
-    val handleId4 = new HandleIdentifier(tHandleId)
-    assert(handleId1 !== handleId4)
-
-  }
-}