diff --git a/dm/dm/config/source_config.go b/dm/dm/config/source_config.go
index 31c4f9564aa..d45cb69fe33 100644
--- a/dm/dm/config/source_config.go
+++ b/dm/dm/config/source_config.go
@@ -308,7 +308,7 @@ func (c *SourceConfig) Adjust(ctx context.Context, db *sql.DB) (err error) {
 		log.L().Warn("using an absolute relay path, relay log can't work when starting multiple relay worker")
 	}
 
-	return c.AdjustCaseSensitive(ctx2, db)
+	return nil
 }
 
 // AdjustCaseSensitive adjust CaseSensitive from DB.
diff --git a/dm/dm/master/bootstrap_test.go b/dm/dm/master/bootstrap_test.go
index fc1a93ee856..8b95b3b292a 100644
--- a/dm/dm/master/bootstrap_test.go
+++ b/dm/dm/master/bootstrap_test.go
@@ -73,7 +73,7 @@ func (t *testMaster) TestCollectSourceConfigFilesV1Import(c *C) {
 	cfg1.From.User = user
 	cfg1.From.Password = password
 	cfg1.RelayDir = "relay-dir"
-	c.Assert(checkAndAdjustSourceConfigFunc(ctx, cfg1), IsNil) // adjust source config.
+	c.Assert(checkAndAdjustSourceConfigForDMCtlFunc(ctx, cfg1), IsNil) // adjust source config.
 	cfg2 := cfg1.Clone()
 	cfg2.SourceID = "mysql-replica-02"
 
diff --git a/dm/dm/master/server.go b/dm/dm/master/server.go
index 5fdafd70337..71ef309489f 100644
--- a/dm/dm/master/server.go
+++ b/dm/dm/master/server.go
@@ -15,6 +15,7 @@ package master
 
 import (
 	"context"
+	"database/sql"
 	"encoding/binary"
 	"fmt"
 	"math/rand"
@@ -86,7 +87,11 @@ var (
 	registerOnce      sync.Once
 	runBackgroundOnce sync.Once
 
-	checkAndAdjustSourceConfigFunc = checkAndAdjustSourceConfig
+	// the difference of below functions is checkAndAdjustSourceConfigForDMCtlFunc will not AdjustCaseSensitive. It's a
+	// compatibility compromise.
+	// When we need to change the implementation of dmctl to OpenAPI, we should notice the user about this change.
+	checkAndAdjustSourceConfigFunc         = checkAndAdjustSourceConfig
+	checkAndAdjustSourceConfigForDMCtlFunc = checkAndAdjustSourceConfigForDMCtl
 )
 
 // Server handles RPC requests for dm-master.
@@ -1311,7 +1316,7 @@ func parseAndAdjustSourceConfig(ctx context.Context, contents []string) ([]*conf
 		if err != nil {
 			return cfgs, err
 		}
-		if err := checkAndAdjustSourceConfigFunc(ctx, cfg); err != nil {
+		if err := checkAndAdjustSourceConfigForDMCtlFunc(ctx, cfg); err != nil {
 			return cfgs, err
 		}
 		cfgs[i] = cfg
@@ -1319,7 +1324,11 @@ func parseAndAdjustSourceConfig(ctx context.Context, contents []string) ([]*conf
 	return cfgs, nil
 }
 
-func checkAndAdjustSourceConfig(ctx context.Context, cfg *config.SourceConfig) error {
+func innerCheckAndAdjustSourceConfig(
+	ctx context.Context,
+	cfg *config.SourceConfig,
+	hook func(sourceConfig *config.SourceConfig, ctx context.Context, db *sql.DB) error,
+) error {
 	dbConfig := cfg.GenerateDBConfig()
 	fromDB, err := conn.DefaultDBProvider.Apply(dbConfig)
 	if err != nil {
@@ -1329,12 +1338,25 @@ func checkAndAdjustSourceConfig(ctx context.Context, cfg *config.SourceConfig) e
 	if err = cfg.Adjust(ctx, fromDB.DB); err != nil {
 		return err
 	}
+	if hook != nil {
+		if err = hook(cfg, ctx, fromDB.DB); err != nil {
+			return err
+		}
+	}
 	if _, err = cfg.Yaml(); err != nil {
 		return err
 	}
 	return cfg.Verify()
 }
 
+func checkAndAdjustSourceConfig(ctx context.Context, cfg *config.SourceConfig) error {
+	return innerCheckAndAdjustSourceConfig(ctx, cfg, (*config.SourceConfig).AdjustCaseSensitive)
+}
+
+func checkAndAdjustSourceConfigForDMCtl(ctx context.Context, cfg *config.SourceConfig) error {
+	return innerCheckAndAdjustSourceConfig(ctx, cfg, nil)
+}
+
 func parseSourceConfig(contents []string) ([]*config.SourceConfig, error) {
 	cfgs := make([]*config.SourceConfig, len(contents))
 	for i, content := range contents {
diff --git a/dm/dm/master/server_test.go b/dm/dm/master/server_test.go
index 1184274e09d..4da797eaeae 100644
--- a/dm/dm/master/server_test.go
+++ b/dm/dm/master/server_test.go
@@ -196,12 +196,12 @@ func (t *testMaster) SetUpSuite(c *check.C) {
 	t.workerClients = make(map[string]workerrpc.Client)
 	t.saveMaxRetryNum = maxRetryNum
 	maxRetryNum = 2
-	checkAndAdjustSourceConfigFunc = checkAndNoAdjustSourceConfigMock
+	checkAndAdjustSourceConfigForDMCtlFunc = checkAndNoAdjustSourceConfigMock
 }
 
 func (t *testMaster) TearDownSuite(c *check.C) {
 	maxRetryNum = t.saveMaxRetryNum
-	checkAndAdjustSourceConfigFunc = checkAndAdjustSourceConfig
+	checkAndAdjustSourceConfigForDMCtlFunc = checkAndAdjustSourceConfig
 }
 
 func (t *testMaster) SetUpTest(c *check.C) {
diff --git a/dm/pkg/utils/common.go b/dm/pkg/utils/common.go
index 8610ae49d17..4fc443dbeb4 100644
--- a/dm/pkg/utils/common.go
+++ b/dm/pkg/utils/common.go
@@ -184,12 +184,13 @@ func FetchLowerCaseTableNamesSetting(ctx context.Context, conn *sql.Conn) (Lower
 	return LowerCaseTableNamesFlavor(res), nil
 }
 
-// GetDBCaseSensitive returns the case sensitive setting of target db.
+// GetDBCaseSensitive returns the case-sensitive setting of target db.
 func GetDBCaseSensitive(ctx context.Context, db *sql.DB) (bool, error) {
 	conn, err := db.Conn(ctx)
 	if err != nil {
 		return true, terror.DBErrorAdapt(err, terror.ErrDBDriverError)
 	}
+	defer conn.Close()
 	lcFlavor, err := FetchLowerCaseTableNamesSetting(ctx, conn)
 	if err != nil {
 		return true, err
diff --git a/dm/tests/all_mode/run.sh b/dm/tests/all_mode/run.sh
index b65ae2a5649..a60e607ace7 100755
--- a/dm/tests/all_mode/run.sh
+++ b/dm/tests/all_mode/run.sh
@@ -96,14 +96,13 @@ function test_query_timeout() {
 	# don't know why CI has turned on Event Scheduler
 	run_sql_both_source 'SET GLOBAL event_scheduler = OFF;'
 
-	# there's only 2 rows in result, one for dm-worker's source-level status, one for SHOW PROCESSLIST
+	# there's only 1 row in result, which is for SHOW PROCESSLIST
 	run_sql_source1 'SHOW PROCESSLIST;'
-	check_rows_equal 2
+	check_rows_equal 1
 
 	run_sql_source2 'SHOW PROCESSLIST;'
-	check_rows_equal 2
+	check_rows_equal 1
 
-	# there's only 1 row in result, which is for SHOW PROCESSLIST
 	run_sql_tidb 'SHOW PROCESSLIST;'
 	check_rows_equal 1
 
@@ -131,14 +130,13 @@ function test_query_timeout() {
 		"stop-task $ILLEGAL_CHAR_NAME" \
 		"\"result\": true" 3
 
-	# there's only 2 rows in result, one for dm-worker's source-level status, one for SHOW PROCESSLIST
+	# there's only 1 row in result, which is for SHOW PROCESSLIST
 	run_sql_source1 'SHOW PROCESSLIST;'
-	check_rows_equal 2
+	check_rows_equal 1
 
 	run_sql_source2 'SHOW PROCESSLIST;'
-	check_rows_equal 2
+	check_rows_equal 1
 
-	# there's only 1 row in result, which is for SHOW PROCESSLIST
 	run_sql_tidb 'SHOW PROCESSLIST;'
 	check_rows_equal 1
 
diff --git a/dm/tests/case_sensitive/data/db2.prepare.sql b/dm/tests/case_sensitive/data/db2.prepare.sql
index 98efbb4b44f..b0e049b679a 100644
--- a/dm/tests/case_sensitive/data/db2.prepare.sql
+++ b/dm/tests/case_sensitive/data/db2.prepare.sql
@@ -8,6 +8,7 @@ create table Upper_Table (
     PRIMARY KEY (id));
 insert into Upper_Table (name, ts) values ('Arya', now()), ('Bran', '2021-05-11 10:01:05'), ('Sansa', NULL);
 
+-- if case-insensitive, this should report conflict with Upper_Table
 create table upper_table(id int NOT NULL PRIMARY KEY);
 
 -- test block-allow-list
diff --git a/dm/tests/case_sensitive/run.sh b/dm/tests/case_sensitive/run.sh
index 3fd1fdaea3d..1beeff327f8 100755
--- a/dm/tests/case_sensitive/run.sh
+++ b/dm/tests/case_sensitive/run.sh
@@ -7,7 +7,22 @@ source $cur/../_utils/test_prepare
 WORK_DIR=$TEST_DIR/$TEST_NAME
 API_VERSION="v1alpha1"
 
-function run() {
+function prepare_sensitive_task() {
+	cp $cur/data/db1.prepare.sql $WORK_DIR/db1.prepare.sql
+	cp $cur/data/db2.prepare.sql $WORK_DIR/db2.prepare.sql
+	cp $cur/conf/dm-task.yaml $WORK_DIR/dm-task.yaml
+}
+
+function prepare_insensitive_task() {
+	cp $cur/data/db1.prepare.sql $WORK_DIR/db1.prepare.sql
+	cp $cur/data/db2.prepare.sql $WORK_DIR/db2.prepare.sql
+	cp $cur/conf/dm-task.yaml $WORK_DIR/dm-task.yaml
+
+	sed -i "/sensitive/d" $WORK_DIR/dm-task.yaml
+	sed -i "/create table upper_table/d" $WORK_DIR/db2.prepare.sql
+}
+
+function run_with_prepared() {
 	run_sql_both_source "SET @@GLOBAL.SQL_MODE='ANSI_QUOTES,NO_AUTO_VALUE_ON_ZERO'"
 	inject_points=(
 		"github.com/pingcap/tiflow/dm/dm/worker/TaskCheckInterval=return(\"500ms\")"
@@ -15,9 +30,9 @@ function run() {
 	)
 	export GO_FAILPOINTS="$(join_string \; ${inject_points[@]})"
 
-	run_sql_file $cur/data/db1.prepare.sql $MYSQL_HOST1 $MYSQL_PORT1 $MYSQL_PASSWORD1
+	run_sql_file $WORK_DIR/db1.prepare.sql $MYSQL_HOST1 $MYSQL_PORT1 $MYSQL_PASSWORD1
 	check_contains 'Query OK, 2 rows affected'
-	run_sql_file $cur/data/db2.prepare.sql $MYSQL_HOST2 $MYSQL_PORT2 $MYSQL_PASSWORD2
+	run_sql_file $WORK_DIR/db2.prepare.sql $MYSQL_HOST2 $MYSQL_PORT2 $MYSQL_PASSWORD2
 	check_contains 'Query OK, 3 rows affected'
 	# manually create the route table
 	run_sql 'CREATE DATABASE IF NOT EXISTS `UPPER_DB_ROUTE`' $TIDB_PORT $TIDB_PASSWORD
@@ -40,7 +55,6 @@ function run() {
 	dmctl_operate_source create $WORK_DIR/source2.yaml $SOURCE_ID2
 
 	# start DM task only
-	cp $cur/conf/dm-task.yaml $WORK_DIR/dm-task.yaml
 	dmctl_start_task "$WORK_DIR/dm-task.yaml" "--remove-meta"
 	# check task has started
 	check_metric $WORKER1_PORT "dm_worker_task_state{source_id=\"mysql-replica-01\",task=\"test\",worker=\"worker1\"}" 10 1 3
@@ -82,7 +96,6 @@ function run() {
 
 	# test block-allow-list by the way
 	run_sql "show databases;" $TIDB_PORT $TIDB_PASSWORD
-	check_not_contains "Upper_Db_IGNORE"
 	check_contains "Upper_DB1"
 	check_contains "lower_db"
 	# test route-rule
@@ -90,7 +103,6 @@ function run() {
 
 	run_sql "show tables from UPPER_DB_ROUTE" $TIDB_PORT $TIDB_PASSWORD
 	check_contains "do_table_route"
-	check_not_contains "Do_table_ignore"
 	run_sql_tidb_with_retry "select count(*) from UPPER_DB_ROUTE.do_table_route" "count(*): 5"
 
 	# test binlog event filter
@@ -101,16 +113,37 @@ function run() {
 	# ensure the truncate is ignored and the new row is inserted
 	run_sql_tidb_with_retry "select count(*) from UPPER_DB_ROUTE.do_table_route" "count(*): 6"
 
+	dmctl_stop_task test
+	dmctl_operate_source stop $WORK_DIR/source1.yaml $SOURCE_ID1
+	dmctl_operate_source stop $WORK_DIR/source2.yaml $SOURCE_ID2
+
 	export GO_FAILPOINTS=''
 }
 
+function check_ignore_when_sensitive() {
+	run_sql "show databases;" $TIDB_PORT $TIDB_PASSWORD
+	check_not_contains "Upper_Db_IGNORE"
+	run_sql "show tables from UPPER_DB_ROUTE" $TIDB_PORT $TIDB_PASSWORD
+	check_not_contains "Do_table_ignore"
+}
+
 trap cleanup_process EXIT
-trap "cleanup_data Upper_DB Upper_DB1 lower_db UPPER_DB_ROUTE sync_diff_inspector" EXIT
+trap "cleanup_data Upper_DB Upper_DB1 lower_db UPPER_DB_ROUTE Upper_Db_IGNORE sync_diff_inspector" EXIT
 
 # also cleanup dm processes in case of last run failed
 cleanup_process $*
-cleanup_data Upper_DB Upper_DB1 lower_db UPPER_DB_ROUTE
-run
+cleanup_data Upper_DB Upper_DB1 lower_db UPPER_DB_ROUTE Upper_Db_IGNORE
+
+prepare_sensitive_task
+run_with_prepared
+check_ignore_when_sensitive
+
+cleanup_process $*
+cleanup_data Upper_DB Upper_DB1 lower_db UPPER_DB_ROUTE Upper_Db_IGNORE
+
+prepare_insensitive_task
+run_with_prepared
+
 cleanup_process $*
 
 echo "[$(date)] <<<<<< test case $TEST_NAME success! >>>>>>"