diff --git a/Makefile b/Makefile
index 98f874945f..1a02b30cdf 100644
--- a/Makefile
+++ b/Makefile
@@ -192,8 +192,8 @@ coverage_fix_cover_mode:
 	sed -i "s/mode: count/mode: atomic/g" $(TEST_DIR)/cov.*.dmctl.*.out
 
 coverage: coverage_fix_cover_mode retool_setup
-	retool do gocovmerge "$(TEST_DIR)"/cov.* | grep -vE ".*.pb.go|.*.__failpoint_binding__.go|.*debug-tools.*|.*portal.*|.*chaos.*" > "$(TEST_DIR)/all_cov.out"
-	retool do gocovmerge "$(TEST_DIR)"/cov.unit_test*.out | grep -vE ".*.pb.go|.*.__failpoint_binding__.go|.*debug-tools.*|.*portal.*|.*chaos.*" > $(TEST_DIR)/unit_test.out
+	retool do gocovmerge "$(TEST_DIR)"/cov.* | grep -vE ".*.pb.go|.*.pb.gw.go|.*.__failpoint_binding__.go|.*debug-tools.*|.*portal.*|.*chaos.*" > "$(TEST_DIR)/all_cov.out"
+	retool do gocovmerge "$(TEST_DIR)"/cov.unit_test*.out | grep -vE ".*.pb.go|.*.pb.gw.go|.*.__failpoint_binding__.go|.*debug-tools.*|.*portal.*|.*chaos.*" > $(TEST_DIR)/unit_test.out
 ifeq ("$(JenkinsCI)", "1")
 	@bash <(curl -s https://codecov.io/bash) -f $(TEST_DIR)/unit_test.out -t $(CODECOV_TOKEN)
 	@retool do goveralls -coverprofile=$(TEST_DIR)/all_cov.out -service=jenkins-ci -repotoken $(COVERALLS_TOKEN)
diff --git a/dm/master/shardddl/optimist.go b/dm/master/shardddl/optimist.go
index e31de1f518..b63da694ea 100644
--- a/dm/master/shardddl/optimist.go
+++ b/dm/master/shardddl/optimist.go
@@ -25,6 +25,7 @@ import (
 	"go.etcd.io/etcd/clientv3"
 	"go.uber.org/zap"
 
+	"github.com/pingcap/dm/dm/common"
 	"github.com/pingcap/dm/dm/config"
 	"github.com/pingcap/dm/dm/master/metrics"
 	"github.com/pingcap/dm/dm/pb"
@@ -549,8 +550,40 @@ func (o *Optimist) handleLock(info optimism.Info, tts []optimism.TargetTable, sk
 func (o *Optimist) removeLock(lock *optimism.Lock) (bool, error) {
 	failpoint.Inject("SleepWhenRemoveLock", func(val failpoint.Value) {
 		t := val.(int)
-		log.L().Info("wait new ddl info putted into etcd", zap.String("failpoint", "SleepWhenRemoveLock"))
-		time.Sleep(time.Duration(t) * time.Second)
+		log.L().Info("wait new ddl info putted into etcd",
+			zap.String("failpoint", "SleepWhenRemoveLock"),
+			zap.Int("max wait second", t))
+
+		ticker := time.NewTicker(time.Second)
+		defer ticker.Stop()
+		timer := time.NewTimer(time.Duration(t) * time.Second)
+		defer timer.Stop()
+	OUTER:
+		for {
+			select {
+			case <-timer.C:
+				log.L().Info("failed to wait new DDL info", zap.Int("wait second", t))
+				break OUTER
+			case <-ticker.C:
+				// manually check etcd
+				cmps := make([]clientv3.Cmp, 0)
+				for source, schemaTables := range lock.Ready() {
+					for schema, tables := range schemaTables {
+						for table := range tables {
+							info := optimism.NewInfo(lock.Task, source, schema, table, lock.DownSchema, lock.DownTable, nil, nil, nil)
+							info.Version = lock.GetVersion(source, schema, table)
+							key := common.ShardDDLOptimismInfoKeyAdapter.Encode(info.Task, info.Source, info.UpSchema, info.UpTable)
+							cmps = append(cmps, clientv3.Compare(clientv3.Version(key), "<", info.Version+1))
+						}
+					}
+				}
+				resp, _, err := etcdutil.DoOpsInOneCmpsTxnWithRetry(o.cli, cmps, nil, nil)
+				if err == nil && !resp.Succeeded {
+					log.L().Info("found new DDL info")
+					break OUTER
+				}
+			}
+		}
 	})
 	deleted, err := o.deleteInfosOps(lock)
 	if err != nil {
diff --git a/dm/master/shardddl/pessimist_test.go b/dm/master/shardddl/pessimist_test.go
index 64eadf53f7..2498a9536a 100644
--- a/dm/master/shardddl/pessimist_test.go
+++ b/dm/master/shardddl/pessimist_test.go
@@ -201,7 +201,7 @@ func (t *testPessimist) testPessimistProgress(c *C, restart int) {
 	done, _, err = pessimism.PutOperationDeleteExistInfo(etcdTestCli, op12c, i12)
 	c.Assert(err, IsNil)
 	c.Assert(done, IsTrue)
-	c.Assert(utils.WaitSomething(30, 100*time.Millisecond, func() bool {
+	c.Assert(utils.WaitSomething(50, 100*time.Millisecond, func() bool {
 		_, ok := p.Locks()[ID1]
 		return !ok
 	}), IsTrue)
diff --git a/pkg/shardddl/optimism/info_test.go b/pkg/shardddl/optimism/info_test.go
index 6479994fa4..efc54679a5 100644
--- a/pkg/shardddl/optimism/info_test.go
+++ b/pkg/shardddl/optimism/info_test.go
@@ -179,7 +179,11 @@ func (t *testForEtcd) TestInfoEtcd(c *C) {
 	resp, err := etcdTestCli.Txn(context.Background()).Then(deleteOp).Commit()
 	c.Assert(err, IsNil)
 	c.Assert(resp.Succeeded, IsTrue)
-	<-wch
+	select {
+	case err2 := <-ech:
+		c.Fatal(err2)
+	case <-wch:
+	}
 
 	// put again
 	// version reset to 1
diff --git a/relay/relay_test.go b/relay/relay_test.go
index 8ba84484fd..56b961dd64 100644
--- a/relay/relay_test.go
+++ b/relay/relay_test.go
@@ -566,8 +566,11 @@ func (t *testRelaySuite) TestProcess(c *C) {
 	// kill the binlog dump connection
 	ctx2, cancel2 := context.WithTimeout(context.Background(), 10*time.Second)
 	defer cancel2()
-	connID, err := getBinlogDumpConnID(ctx2, r.db)
-	c.Assert(err, IsNil)
+	var connID uint32
+	c.Assert(utils.WaitSomething(30, 100*time.Millisecond, func() bool {
+		connID, err = getBinlogDumpConnID(ctx2, r.db)
+		return err == nil
+	}), IsTrue)
 	_, err = r.db.ExecContext(ctx2, fmt.Sprintf(`KILL %d`, connID))
 	c.Assert(err, IsNil)
 
diff --git a/tests/_utils/test_prepare b/tests/_utils/test_prepare
index 270529f527..6f2ddb7981 100644
--- a/tests/_utils/test_prepare
+++ b/tests/_utils/test_prepare
@@ -204,7 +204,7 @@ function check_log_contain_with_retry() {
             continue
         fi
         got=`grep "$text" $log1 | wc -l`
-        if [[ ! $got = 0 ]]; then
+        if [[ $got -ne 0 ]]; then
             rc=1
             break
         fi
@@ -215,7 +215,7 @@ function check_log_contain_with_retry() {
                 continue
             fi
             got=`grep "$text" $log2 | wc -l`
-            if [[ ! $got = 0 ]]; then
+            if [[ $got -ne 0 ]]; then
                 rc=1
                 break
             fi
@@ -223,7 +223,7 @@ function check_log_contain_with_retry() {
         echo "check log contain failed $k-th time, retry later"
         sleep 2
     done
-    if [[ $rc = 0 ]]; then
+    if [[ $rc -eq 0 ]]; then
         echo "log dosen't contain $text"
         exit 1
     fi
diff --git a/tests/ha_cases/run.sh b/tests/ha_cases/run.sh
index 66f39d535b..abfc3fe566 100755
--- a/tests/ha_cases/run.sh
+++ b/tests/ha_cases/run.sh
@@ -72,8 +72,8 @@ function test_multi_task_running() {
 
     sleep 5 # wait for flush checkpoint
     echo "use sync_diff_inspector to check increment data"
-    check_sync_diff $WORK_DIR $cur/conf/diff_config.toml 10 || print_debug_status
-    check_sync_diff $WORK_DIR $cur/conf/diff_config_multi_task.toml 10 || print_debug_status
+    check_sync_diff $WORK_DIR $cur/conf/diff_config.toml 50 || print_debug_status
+    check_sync_diff $WORK_DIR $cur/conf/diff_config_multi_task.toml 50 || print_debug_status
     echo "[$(date)] <<<<<< finish test_multi_task_running >>>>>>"
 }
 
@@ -421,14 +421,15 @@ function test_pause_task() {
     task_name=(test test2)
     for name in ${task_name[@]}; do
         echo "pause tasks $name"
+
+        # because some SQL may running (often remove checkpoint record), pause will cause that SQL failed
+        # thus `result` is not true
         run_dm_ctl $WORK_DIR "127.0.0.1:$MASTER_PORT" \
-            "pause-task $name"\
-            "\"result\": true" 3
+            "pause-task $name"
 
         # pause twice, just used to test pause by the way
         run_dm_ctl $WORK_DIR "127.0.0.1:$MASTER_PORT" \
-            "pause-task $name"\
-            "\"result\": true" 3
+            "pause-task $name"
         
         run_dm_ctl $WORK_DIR "127.0.0.1:$MASTER_PORT" \
             "query-status $name"\
diff --git a/tests/shardddl3/run.sh b/tests/shardddl3/run.sh
index 5d7b185ee2..5821dc99de 100644
--- a/tests/shardddl3/run.sh
+++ b/tests/shardddl3/run.sh
@@ -610,6 +610,23 @@ function DM_102_CASE() {
     run_sql_source1 "insert into ${shardddl1}.${tb1} values (1,1);"
     run_sql_source2 "alter table ${shardddl1}.${tb1} add column new_col1 int default -1;"
 
+    sleep 1
+    # wait DM receive source2's DDL
+    found=false
+    for ((k=0; k<10; k++)); do
+        content=$($PWD/bin/dmctl.test DEVEL --master-addr=127.0.0.1:$MASTER_PORT query-status test)
+        master2=$(echo $content | sed 's/"masterBinlog":/"masterBinlog":\n/g' | awk -F')' 'FNR==3{print $1}')
+        syncer2=$(echo $content | sed 's/"syncerBinlog":/"syncerBinlog":\n/g' | awk -F')' 'FNR==3{print $1}')
+        if [ "$master2" != "$syncer2" ]; then
+            found=true
+            break
+        fi
+    done
+    if [[ $found == false ]]; then
+        echo "didn't receive mismatched DDL"
+        exit 2
+    fi
+
     run_dm_ctl_with_retry $WORK_DIR "127.0.0.1:$MASTER_PORT" \
         "show-ddl-locks" \
         "\"ID\": \"test-\`shardddl\`.\`tb\`\"" 1
@@ -683,7 +700,7 @@ function DM_RemoveLock_CASE() {
 function DM_RemoveLock() {
     ps aux | grep dm-master |awk '{print $2}'|xargs kill || true
     check_port_offline $MASTER_PORT1 20
-    export GO_FAILPOINTS="github.com/pingcap/dm/dm/master/shardddl/SleepWhenRemoveLock=return(5)"
+    export GO_FAILPOINTS="github.com/pingcap/dm/dm/master/shardddl/SleepWhenRemoveLock=return(10)"
     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
     run_dm_ctl_with_retry $WORK_DIR "127.0.0.1:$MASTER_PORT" \