TiCDC canal-json 协议下 WATERMARK Event 消息是什么？

我消费了下，不知这个有啥业务的价值，等待大佬出现

{
	"id": 0,
	"database": "",
	"table": "",
	"pkNames": null,
	"isDdl": false,
	"type": "TIDB_WATERMARK",
	"es": 1659085352032,
	"ts": 1659085354502,
	"sql": "",
	"sqlType": null,
	"mysqlType": null,
	"data": null,
	"old": null,
	"_tidb": {
		"watermarkTs": 434919270523076621
	}
}