diff --git a/tests/_utils/shardddl_lib.sh b/tests/_utils/shardddl_lib.sh
index 9c0733d669..39bcacc7c8 100644
--- a/tests/_utils/shardddl_lib.sh
+++ b/tests/_utils/shardddl_lib.sh
@@ -47,8 +47,9 @@ function clean_table() {
 
 function restart_master() {
 	echo "restart dm-master"
-	wait_process_exit dm-master.test
+	ps aux | grep dm-master | awk '{print $2}' | xargs kill || true
 	check_port_offline $MASTER_PORT 20
+	sleep 2
 
 	run_dm_master $WORK_DIR/master $MASTER_PORT $cur/conf/dm-master.toml
 	check_rpc_alive $cur/../bin/check_master_online 127.0.0.1:$MASTER_PORT
diff --git a/tests/_utils/wait_process_exit b/tests/_utils/wait_process_exit
index 3530e8020f..b3b6fa75e0 100755
--- a/tests/_utils/wait_process_exit
+++ b/tests/_utils/wait_process_exit
@@ -1,29 +1,20 @@
 #!/bin/bash
 # parameter 1: process name
-process=$1
-
-PID=$(pgrep $process)
-if [ -z "$PID" ]; then
-	echo "process $process already exit"
-	exit
-fi
 
-WAIT_COUNT=10
-KILL_TIMES=1 # make sure only send kill -9 once.
-count=0
+process=$1
 
-while true; do
+WAIT_COUNT=0
+while [ $WAIT_COUNT -lt 30 ]; do
 	pgrep $process >/dev/null 2>&1
 	ret=$?
 	if [ "$ret" != "0" ]; then
 		echo "process $process already exit"
-		break
+		exit 0
 	fi
-	sleep 0.2
-	((count++))
+	sleep 1
 	echo "wait process $process exit..."
-	if [ $count -gt $WAIT_COUNT ] && [ $KILL_TIMES -lt 2 ]; then
-		((KILL_TIMES++))
-		kill -9 $PID || true
-	fi
+	((WAIT_COUNT++))
 done
+
+echo "process $process didn't exit after 30 seconds"
+exit 1
diff --git a/tests/tiup/lib.sh b/tests/tiup/lib.sh
index 082fa2b17e..ad9eb4134b 100755
--- a/tests/tiup/lib.sh
+++ b/tests/tiup/lib.sh
@@ -59,8 +59,8 @@ function exec_full_stage() {
 	exec_sql mariadb2 3306 "INSERT INTO $DB2.$TBL3 (c1, c2) VALUES (12, '12');"
 
 	# prepare optimsitic full data
-	exec_sql mysql1 3306 "CREATE DATABASE $DB3;"
-	exec_sql mariadb2 3306 "CREATE DATABASE $DB4;"
+	exec_sql mysql1 3306 "CREATE DATABASE $DB3 CHARACTER SET UTF8MB4 COLLATE utf8mb4_bin;"
+	exec_sql mariadb2 3306 "CREATE DATABASE $DB4 CHARACTER SET UTF8MB4 COLLATE utf8mb4_bin;"
 	exec_sql mysql1 3306 "CREATE TABLE $DB3.$TBL1 (c1 INT PRIMARY KEY, c2 TEXT);"
 	exec_sql mysql1 3306 "CREATE TABLE $DB3.$TBL2 (c1 INT PRIMARY KEY, c2 TEXT);"
 	exec_sql mariadb2 3306 "CREATE TABLE $DB4.$TBL2 (c1 INT PRIMARY KEY, c2 TEXT);"