TiDB 4.0.0 Beta.2 Release Notes

Release date: March 18, 2020

TiDB version: 4.0.0-beta.2

TiDB Ansible version: 4.0.0-beta.2

Compatibility Changes

Tools
- TiDB Binlog
  - Fix the issue that the system returns an error and exits when disable-dispatch and disable-causality are configured in Drainer #915

TiKV
- Support persisting the dynamically updated configuration into the hardware disk #6684
PD
- Support persisting the dynamically updated configuration into the hardware disk #2153
Tools
- TiDB Binlog
  - Support the bidirectional data replication between TiDB clusters #879 #903
- TiDB Lightning
  - Support the TLS configuration #40 #270
- TiCDC
  - Initial release of the change data capture (CDC), providing the following features:
    - Support capturing changed data from TiKV
    - Support replicating the changed data from TiKV to MySQL compatible databases, and guarantee the eventual data consistency
    - Support replicating the changed data to Kafka, and guarantee either the eventual data consistency or the row-level orderliness
    - Provide process-level high availability
- Backup & Restore (BR)
  - Enable experimental features such as incremental backup and backing up files to Amazon S3 #175
TiDB Ansible
- Support injecting the node information to etcd #1196
- Support deploying TiDB services on the ARM platform #1204

TiKV
- Fix the panic issue that might occur when meeting empty short values during the backup #6718
- Fix the issue that Hibernate Regions might not be correctly awakened in some cases #6772 #6648 #6376
PD
- Fix the panic issue that the rule checker fails to allocate stores to Regions #2160
- Fix the issue that after the dynamic configuration is enabled, the configuration might have replication delay when the Leader is being switched #2154
Tools
- Backup & Restore (BR)
  - Fix the issue that BR might fail to restore data of a large size because PD cannot process large-sized data #167
  - Fix the BR failure occurred because the BR version is not compatible with the TiDB version #186
  - Fix the BR failure occurred because the BR version is not compatible with TiFlash #194