PD transfers leader to a pending peer

[jiyingtk]

Please answer these questions before submitting your issue. Thanks!

1. What did you do?

./pd-ctl -u 10.233.100.247:2379 region 56317
{
  "id": 56317,
  "start_key": "7480000000000000FFF55F698000000000FF0000010130303030FF30303030FF303030FF3030303030FF3030FF303030303030FF30FF30303030303030FFFF3030303030303032FFFF34303231313336FF38FF000000000000FF0000F70400000000FF0E5155A801376162FF3366363833FF6639FF643766333135FF38FF63363065663435FFFF3139313933396236FFFF00000000000000FF00F7040000000000FF0000000400000000FF0000000000000000FB",
  "end_key": "7480000000000000FFF55F698000000000FF0000010130303030FF30303030FF303030FF3030303030FF3030FF303030303030FF30FF30303030303030FFFF3030303030303032FFFF35303038343932FF34FF000000000000FF0000F70400000000FF0EE7FE3F01383431FF6330386162FF6530FF313031376536FF38FF39326137636363FFFF3033656138373462FFFF00000000000000FF00F7040000000000FF0000000400000000FF0000000000000000FB",
  "epoch": {
    "conf_ver": 37,
    "version": 237
  },
  "peers": [
    {
      "id": 56318,
      "store_id": 1
    },
    {
      "id": 56319,
      "store_id": 6
    },
    {
      "id": 56320,
      "store_id": 9
    },
    {
      "id": 57144,
      "store_id": 5
    }
  ],
  "leader": {
    "id": 56318,
    "store_id": 1
  },
  "pending_peers": [
    {
      "id": 56319,
      "store_id": 6
    }
  ],
  "written_bytes": 19350993,
  "approximate_size": 123,
  "approximate_keys": 624077
}

2. What did you expect to see?

PD will do scheduling quickly.

3. What did you see instead?

PD tries to transfer leader for region 56317 from store 1 to store 6 which contains a pending peer, and it makes PD to repeatedly do this operation, which blocks the scheduling procedure.
hot-region.log

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

Release Version: v3.0.0-2-gee98bf9
Git Commit Hash: ee98bf9063e9aef9e23e02fdf0a3b20b96e32d20
Git Branch: pingcap/release-3.0
UTC Build Time:  2019-07-11 03:50:52

[ljluestc]

The version you mentioned, v3.0.0-2-gee98bf9 is outdated