/region in the API may return a huge written_keys

[HunDunDM]

Bug Report

/region in the API returned a result as follows

{
	"id": 29031958,
	"start_key": "******",
	"end_key": "******",
	"epoch": {
		"conf_ver": 1204,
		"version": 33785
	},
	"peers": [{
		"id": 29031959,
		"store_id": 5678246
	}, {
		"id": 29031960,
		"store_id": 1
	}, {
		"id": 29031961,
		"store_id": 5678148
	}],
	"leader": {
		"id": 29031961,
		"store_id": 5678148
	},
	"pending_peers": [{
		"id": 29031960,
		"store_id": 1
	}],
	"written_bytes": 18446744073709550591,
	"read_bytes": 0,
	"written_keys": 18446744073709551615,
	"read_keys": 0,
	"approximate_size": 93,
	"approximate_keys": 504338
}

What did you do?

• pd-ctl region

What did you expect to see?

• This is a cold region and should have smaller written_bytes.

What did you see instead?

• written_bytes = 18446744073709550591 = uint64(-1024)
• written_keys = 18446744073709551615 = uint64(-1)

Other information that may be useful

• The information may not be updated for a long time
  • It may be due to a bug fixed by config: refine config clone #3116
• In TiDB code, the type of this field is int64, which will cause the following error.
  • json: cannot unmarshal number 18446744073709550591 into Go struct field .written_bytes of type int64
• This data comes from TiKV's region heartbeat data.

What version of PD are you using (pd-server -V)?

• v4.0.9

[rleungx]

Fixed by tikv/tikv#10119