diff --git a/internal/msggateway/client_conn.go b/internal/msggateway/client_conn.go
index 15a0d8c07..0fb1620a6 100644
--- a/internal/msggateway/client_conn.go
+++ b/internal/msggateway/client_conn.go
@@ -208,7 +208,11 @@ func (c *websocketClientConn) pingHandler(appData string) error {
 	return nil
 }
 
-func (c *websocketClientConn) pongHandler(string) error {
+func (c *websocketClientConn) pongHandler(appData string) error {
+	log.ZDebug(context.Background(), "pong handler recv pong", "remoteAddr", c.conn.RemoteAddr(), "appData", appData)
+	if err := c.setReadDeadline(); err != nil {
+		return err
+	}
 	return nil
 }
 
diff --git a/pkg/common/storage/database/mgo/conversation.go b/pkg/common/storage/database/mgo/conversation.go
index 2f9c063cc..30f08f5e5 100644
--- a/pkg/common/storage/database/mgo/conversation.go
+++ b/pkg/common/storage/database/mgo/conversation.go
@@ -47,6 +47,12 @@ func NewConversationMongo(db *mongo.Database) (*ConversationMgo, error) {
 			},
 			Options: options.Index(),
 		},
+		{
+			Keys: bson.D{
+				{Key: "conversation_id", Value: 1},
+			},
+			Options: options.Index(),
+		},
 	})
 	if err != nil {
 		return nil, errs.Wrap(err)