TiDB 3.1 Beta.2 Release Notes

Release date: March 9, 2020

TiDB version: 3.1.0-beta.2

TiDB Ansible version: 3.1.0-beta.2

Compatibility Changes

• Tools
  • TiDB Lightning
    • Use the default configurations specified in theTiDB Lightning Configurationfor certain items not configured in the configuration file#255
    • Add the--tidb-passwordCLI parameter to set the TiDB password#253

New Features

• TiDB
  • Support adding theAutoRandomkeyword in the column attribute to enable TiDB to automatically assign random integers to the primary key, which avoids the write hot spot caused by theAUTO_INCREMENTprimary key#14555
  • Support creating or deleting column store replicas through DDL statements#14537
  • Add the feature that the optimizer can independently select different storage engines#14537
  • Add the feature that the SQL hint supports different storage engines#14537
  • Support reading data from followers by using thetidb_replica_readsystem variable#13464
• TiKV
  • Raftstore
    • Add thepeer_addressparameter to connect other nodes to the TiKV server#6491
    • Add theread_indexandread_index_respmonitoring metrics to monitor the number ofReadIndexrequests#6610
• PD Client
  • 支持本地线程统计报告s to PD#6605
• Backup
  • Replace theRocksIOLimiterflow control library with Rust’sasync-speed-limitflow control library to eliminate extra memory copies when backing up a file#6462
• PD
  • Tolerate backslash in the location label name#2084
• TiFlash
  • Initial release
• TiDB Ansible
  • Support deploying multiple Grafana/Prometheus/Alertmanager in one cluster#1143
  • Support deploying the TiFlash component#1148
  • Add monitoring metrics related to the TiFlash component#1152

Bug Fixes

• TiKV
  • Raftstore
    • Fix the issue that the read requests cannot be processed because data is not properly read from Hibernate Regions#6450
    • Fix the panic issue caused by theReadIndexrequests during the leader transfer process#6613
    • Fix the issue that Hibernate Regions are not correctly awakened in some special conditions#6730#6737#6972
  • Backup
    • Fix the inconsistent data index during the restoration caused by the backup of the extra data# 6659
    • Fix the panic caused by incorrectly processing the deleted values during the backup#6726
• PD
  • Fix the panic occurred because the rule checker fails to assign stores to Regions#2161
• Tools
  • TiDB Lightning
    • Fix the bug that the web interface does not work outside the Server mode#259
  • BR (Backup and Restore)
    • Fix the issue that BR cannot exit in time due to an unrecoverable error it encounters when restoring data#152
• TiDB Ansible
  • Fix the issue that the rolling update command fails because the PD Leader cannot be obtained in some scenarios#1122