diff --git a/lib/mo-tester-1.0-SNAPSHOT.jar b/lib/mo-tester-1.0-SNAPSHOT.jar
index 03ec74e4e..d6127a1d8 100644
Binary files a/lib/mo-tester-1.0-SNAPSHOT.jar and b/lib/mo-tester-1.0-SNAPSHOT.jar differ
diff --git a/mo.yml b/mo.yml
index b441d91e5..3adc48911 100755
--- a/mo.yml
+++ b/mo.yml
@@ -15,8 +15,12 @@ jdbc:
     useLocalSessionState: "true"
     zeroDateTimeBehavior: "CONVERT_TO_NULL"
     failoverReadOnly: "false"
+    initialTimeout: 60
+    autoReconnect: "true"
+    maxReconnects: 4
     serverTimezone: "Asia/Shanghai"
     socketTimeout: 120000
+    
 #users
 user:
   name: "dump"
diff --git a/src/main/java/io/mo/Tester.java b/src/main/java/io/mo/Tester.java
index cd9de4e00..91445953c 100755
--- a/src/main/java/io/mo/Tester.java
+++ b/src/main/java/io/mo/Tester.java
@@ -320,6 +320,10 @@ public static boolean isInclude(String name){
     
     public static void cleanDatabases(){
         Connection connection = ConnectionManager.getConnection();
+        if(connection == null){
+            LOG.error("Failed to clean databases,please check the error,the program will exit.");
+            System.exit(1);
+        }
         String dropDB = "DROP DATABASE IF EXISTS `%s`";
         String[] dbs = RunConfUtil.getBuiltinDb();
         try {
diff --git a/src/main/java/io/mo/db/ConnectionManager.java b/src/main/java/io/mo/db/ConnectionManager.java
index 6c7ad52cb..1d61680cf 100755
--- a/src/main/java/io/mo/db/ConnectionManager.java
+++ b/src/main/java/io/mo/db/ConnectionManager.java
@@ -34,7 +34,7 @@ public static Connection getConnection(int index){
         if(!server_up) return null;
 
         //get db connection,if failed,retry 3 times 10 s interval 
-        for(int i = 0; i < 3; i++) {
+        //for(int i = 0; i < 3; i++) {
             try {
                 Class.forName(driver);
                 if (connections[index] == null || connections[index].isClosed()) {
@@ -43,7 +43,8 @@ public static Connection getConnection(int index){
                 }
                 return connections[index];
             } catch (SQLException e) {
-                LOG.error("The mo-tester can not get valid conneciton from mo with[user="+userName+", pwd="+pwd+"], and will wait 10 seconds and retry...");
+                //LOG.error("The mo-tester can not get valid conneciton from mo with[user="+userName+", pwd="+pwd+"], and will wait 10 seconds and retry...");
+                LOG.error(e.getMessage());
                 try {
                     Thread.sleep(10000);
                 } catch (InterruptedException ex) {
@@ -52,9 +53,9 @@ public static Connection getConnection(int index){
             } catch (ClassNotFoundException e) {
                 e.printStackTrace();
             }
-        }
-
-        LOG.error("The mo-tester still can not get valid conneciton from mo, the following cases wil not be executed!");
+        //}
+        
+        LOG.error("The mo-tester can not get valid conneciton from mo with[user="+userName+", pwd="+pwd+"], the following cases wil not be executed!");
         server_up = false;
         return null;
     }
@@ -64,7 +65,7 @@ public static Connection getConnection(int index, String userName, String pwd){
         if(!server_up) return null;
 
         //get db connection,if failed,retry 3 times 10 s interval 
-        for(int i = 0; i < 3; i++) {
+        //for(int i = 0; i < 3; i++) {
             try {
                 Class.forName(driver);
                 if (connections[index] == null || connections[index].isClosed()) {
@@ -74,7 +75,8 @@ public static Connection getConnection(int index, String userName, String pwd){
                 }
                 return connections[index];
             } catch (SQLException e) {
-                LOG.error("The mo-tester can not get valid conneciton from mo with[user="+userName+", pwd="+pwd+"], and will wait 10 seconds and retry...");
+                //LOG.error("The mo-tester can not get valid conneciton from mo with[user="+userName+", pwd="+pwd+"], and will wait 10 seconds and retry...");
+                LOG.error(e.getMessage());
                 try {
                     Thread.sleep(10000);
                 } catch (InterruptedException ex) {
@@ -83,9 +85,9 @@ public static Connection getConnection(int index, String userName, String pwd){
             } catch (ClassNotFoundException e) {
                 e.printStackTrace();
             }
-        }
+        //}
 
-        LOG.error("The mo-tester still can not get valid conneciton from mo, the following cases wil not be executed!");
+        LOG.error("The mo-tester can not get valid conneciton from mo with[user="+userName+", pwd="+pwd+"], the following cases wil not be executed!");
         server_up = false;
         return null;
     }
@@ -95,7 +97,7 @@ public static Connection getConnectionForSys(){
         if(!server_up) return null;
 
         //get db connection,if failed,retry 3 times 10 s interval 
-        for(int i = 0; i < 3; i++) {
+        //for(int i = 0; i < 3; i++) {
             try {
                 Class.forName(driver);
                 if (sysconn == null || sysconn.isClosed()) {
@@ -103,7 +105,7 @@ public static Connection getConnectionForSys(){
                 }
                 return sysconn;
             } catch (SQLException e) {
-                LOG.error("The mo-tester can not get valid conneciton from mo with[user="+userName+", pwd="+pwd+"] for sys user, and will wait 10 seconds and retry...");
+                //LOG.error("The mo-tester can not get valid conneciton from mo with[user="+userName+", pwd="+pwd+"] for sys user, and will wait 10 seconds and retry...");
                 try {
                     Thread.sleep(10000);
                 } catch (InterruptedException ex) {
@@ -112,9 +114,9 @@ public static Connection getConnectionForSys(){
             } catch (ClassNotFoundException e) {
                 e.printStackTrace();
             }
-        }
+        //}
 
-        LOG.error("The mo-tester still can not get valid conneciton from mo for sys user, the following cases wil not be executed!");
+        LOG.error("The mo-tester can not get valid conneciton from mo with[user="+userName+", pwd="+pwd+"], the following cases wil not be executed!");
         server_up = false;
         return null;
     }