TiDB 3.1.0 GA Release Notes

Release date: April 16, 2020

TiDB version: 3.1.0 GA

TiDB Ansible version: 3.1.0 GA

Compatibility Changes

• TiDB

  • Support directly stopping starting TiDB if the HTTP listening port is unavailable when the report-status configuration item is enabled #16291

• Tools

  • Backup & Restore (BR)

    • BR does not support restoring data from the TiKV cluster earlier than 3.1 GA #233

New Features

• TiDB

  • Support displaying the information of Coprocessor tasks in explain format = "dot" #16125
  • Reduce the redundant stack information of log using the disable-error-stack configuration item #16182

• Placement Driver (PD)

  • Optimize the hot Region scheduling #2342

• TiFlash

  • Add the metrics report related to the read and write workloads of DeltaTree engine
  • Support pushing down the fromUnixTime and dateFormat functions
  • Disable the rough set filter by default

• TiDB Ansible

  • Add TiFlash monitor #1253 #1257
  • Optimize the configuration parameters of TiFlash #1262 #1265 #1271
  • Optimize the TiDB starting script #1268

Bug Fixes

• TiDB

  • Fix the panic issue caused by the merge join operation in some scenarios #15920
  • Fix the issue that some expressions are repeatedly counted in selectivity calculation #16052
  • Fix the panic issue occurred when loading the statistics information in extreme cases #15710
  • Fix the issue that an error is returned in some cases when equivalent expressions cannot be recognized in SQL query #16015
  • Fix the issue that an error is returned when querying the view of one database from another database #15867
  • Fix the panic issue that occurs when the column is handled using fast analyze #16080
  • Fix the incorrect character set of the current_role print result #16084
  • Refine the log of MySQL connection handshake error #15799
  • Fix the panic issue caused by port probing after the audit plugin is loaded #16065
  • Fix the panic issue of the sort operator on left join because the TypeNull class is mistaken as a variable-length type #15739
  • Fix the issue of inaccurate count of monitoring session retry errors #16120
  • Fix the issue of wrong results of weekday in the ALLOW_INVALID_DATES mode #16171
  • Fix the issue that Garbage Collection (GC) might not work normally when the cluster has TiFlash nodes #15761
  • Fix the issue that TiDB goes out of memory (OOM) when users set a large partition count when creating the hash partitioned table #16219
  • Fix the issue that warnings are mistaken as errors, and make the UNION statement have the same behavior as the SELECT statement #16138
  • Fix the execution error when TopN is pushed down to mocktikv #16200
  • Increase the initial length of chunk.column.nullBitMap to avoid unnecessary overhead of runtime.growslice #16142

• TiKV

  • Fix the panic issue caused by replica read #7418 #7369
  • Fix the issue that the restoration process creates empty Regions #7419
  • Fix the issue that repeated resolve lock requests might harm the atomicity of pessimistic transactions #7389

• TiFlash

  • Fix the potential issue of the rename table operation when replicating the schema from TiDB
  • Fix the issue of data loss caused by the rename table operation under multiple data path configurations
  • Fix the issue that TiFlash reports incorrect storage space in some scenarios
  • Fix the potential issue caused by reading from TiFlash when Region Merge is enabled

• Tools

  • TiDB Binlog

    • Fix the issue that TiFlash-related DDL jobs might interrupt the replication of Drainer #948 #942

  • Backup & Restore (BR)

    • Fix the issue that the checksum operation is still executed when it is disabled #223
    • Fix the issue that incremental backup fails when TiDB enables auto-random or alter-pk #230 #231