TiDB 3.1.0 released, distributed NewSQL database

TiDB 3.1.0 is now released, the updated content of this version is as follows: 

Compatibility changes

• TiDB
  • Support TiDB when starting the service report-status , if the configuration item is turned on  , if it is found that the HTTP listening port is not available, then directly exit the startup  # 16291
• Tools
  • Backup & Restore (BR)
    • BR does not support recovery on TiKV clusters before version 3.1 GA  # 233

new function

• TiDB
  • Support  explain format = "dot" displaying information about coprocessor tasks in  # 16125
  • disable-error-stack Reduce the redundant stack information of logs through  configuration items  # 16182
• Placement Driver (PD)
  • Optimize hotspot Region scheduling  # 2342
• TiFlash
  • Add reporting metric information related to DeltaTree engine read and write load
  • Support  fromUnixTime and  dateFormat function pushdown
  • Coarse-grained index filter is disabled by default
• TiDB Ansible
  • Added TiFlash monitoring  # 1253  # 1257
  • Optimize TiFlash configuration parameters  # 1262  # 1265  # 1271
  • Optimized TiDB startup script  # 1268

Bug fix

• TiDB
  • Fix panic problem of merge join in certain scenes  # 15920
  • Fix the problem of repeatedly considering certain expressions when calculating the selection rate  # 16052
  • Fix panic problem that may appear in load statistics in extreme cases  # 15710
  • Fix the problem that the equivalent expression in the SQL query cannot be recognized in some cases, leading to an error  # 16015
  • Fix the view error when  querying one database from another database  # 15867
  • Fix panic problem when fast analyze handle column  # 16080
  • Fix the  current_role incorrect character set of the output result  # 16084
  • Improve logs related to MySQL connection handshake errors  # 15799
  • Fix panic issue after port audit activity after loading audit plugin  # 16065
  • Fix  the problem TypeNull that the sortoperator is panic  on the left join because the  class is incorrectly recognized as a variable-length type  # 15739
  • Fix inaccurate count of monitoring session retry error  # 16120
  • Fix  the problem of wrong results  in  ALLOW_INVALID_DATES mode # 16171weekday
  • Fix the problem that GC may not work normally when TiFlash node exists in the cluster  # 15761
  • Fix TiDB OOM when creating a very large number of partitions when creating a hash partition table  # 16219
  • Keep  union the behavior of the  select statement the same as the statement, and fix the problem of using warnings as  errors # 16138
  • Fix  TopN execution error pushed down to mocktikv  # 16200
  • Increase  chunk.column.nullBitMap the initialization length to avoid unnecessary  runtime.growslice overhead.  # 16142
• TiKV
  • Fix the issue of replica read causing TiKV panic  # 7418  # 7369
  • Fix the problem that restore produces many empty  regions # 7419
  • Fix an issue where repeated resolve lock requests may destroy the atomicity of pessimistic transactions  # 7389
• TiFlash
  • Fix rename table potential problems when synchronizing schema from TiDB 
  • Fix rename table the problem of data loss caused by multi-data path configuration 
  • Fixed an issue where TiFlash storage space reported errors under certain scenarios
  • Fix potential problems when reading from TiFlash with Region Merge turned on
• Tools
  • TiDB Binlog
    • Fix the issue that Drainer synchronization interrupted due to TiFlash related DDL job  # 948  # 942 # 942
  • BR
    • Fix the problem that checksum is still executed when checksum is closed  # 223
    • Fix the problem that the incremental backup fails when TiDB starts auto-random or alter-pk  # 230  # 231

Update instructions: https://pingcap.com/docs-cn/v3.1/releases/3.1.0-ga/