diff --git a/downstreamadapter/eventcollector/event_collector.go b/downstreamadapter/eventcollector/event_collector.go
index 6f9a5215b9..e543ceacce 100644
--- a/downstreamadapter/eventcollector/event_collector.go
+++ b/downstreamadapter/eventcollector/event_collector.go
@@ -39,7 +39,7 @@ import (
 const (
 	receiveChanSize               = 1024 * 8
 	commonMsgRetryQuota           = 3 // The number of retries for most droppable dispatcher requests.
-	eventServiceHeartbeatInterval = time.Second
+	eventServiceHeartbeatInterval = time.Second * 10
 )
 
 // DispatcherMessage is the message send to EventService.
diff --git a/pkg/eventservice/event_broker.go b/pkg/eventservice/event_broker.go
index 21bdb93641..274ce64b9d 100644
--- a/pkg/eventservice/event_broker.go
+++ b/pkg/eventservice/event_broker.go
@@ -270,6 +270,8 @@ func (c *eventBroker) refreshMinSentResolvedTs(ctx context.Context) error {
 		case <-ctx.Done():
 			return context.Cause(ctx)
 		case <-ticker.C:
+			// for test
+			continue
 			c.changefeedMap.Range(func(key, value interface{}) bool {
 				status := value.(*changefeedStatus)
 				status.refreshMinSentResolvedTs()
@@ -434,7 +436,9 @@ func (c *eventBroker) getScanTaskDataRange(task scanTask) (bool, common.DataRang
 	// this dispatcher still has pending ddl to catch up.
 	hasPendingDDLEventInCurrentRange := dataRange.CommitTsStart < ddlState.MaxEventCommitTs &&
 		ddlState.MaxEventCommitTs <= commitTsEndBeforeWindow
-	scanMaxTs := task.changefeedStat.getScanMaxTs()
+	//scanMaxTs := task.changefeedStat.getScanMaxTs()
+	// fizz for test
+	scanMaxTs := uint64(0)
 	if scanMaxTs > 0 {
 		dataRange.CommitTsEnd = min(dataRange.CommitTsEnd, scanMaxTs)
 		if dataRange.CommitTsEnd < commitTsEndBeforeWindow {
@@ -477,7 +481,7 @@ func (c *eventBroker) getScanTaskDataRange(task scanTask) (bool, common.DataRang
 		// Scan range can become empty after applying capping (for example, scan window).
 		// Send a signal resolved-ts event (rate limited) to keep downstream responsive,
 		// but do not advance the watermark here.
-		c.sendSignalResolvedTs(task)
+		//c.sendSignalResolvedTs(task)
 		return false, common.DataRange{}
 	}