TiDB 4.0.1 Release Notes

Release date: June 12, 2020

TiDB version: 4.0.1

New Features

TiKV
- Add the --advertise-status-addr start flag to specify the status address to advertise #8046
PD
- Support the internal proxy for the built-in TiDB Dashboard #2511
- Support setting a custom timeout for PD client #2509
TiFlash
- Support the TiDB new collation framework
- Support pushing down the If/BitAnd/BitOr/BitXor/BitNot/Json_length functions to TiFlash
- Support the Resolve Lock logic for large transactions in TiFlash
Tools
- Backup & Restore (BR)
  - Add a version check when starting BR to avoid the issue that BR and the TiDB cluster are incompatible #311

TiKV
- Fix the issue that the use-unified-pool configuration in the startup log is incorrectly printed #7946
- Fix the issue that the tikv-ctl does not support relative path #7963
- Fix the bug that the monitoring metric of Point Selects is inaccurate #8033
- Fix the issue that a peer might not be destroyed after the network isolation disappears #8006
- Fix the issue that a request for read index might get outdated commit index #8043
- Improve the reliability of backup and restore with S3 and GCS storages #7917
PD
- Prevent misconfiguration of Placement Rules in some situations #2516
- Fix the issue that deleting the Placement Rule might cause panic #2515
- Fix a bug that the store information cannot be obtained when the store's used size is zero #2474
TiFlash
- Fix the issue that default value of the bit type column in TiFlash is incorrectly parsed
- Fix the miscalculation of 1970-01-01 00:00:00 UTC in some timezones in TiFlash