TiDB 2.1.17 release, NewSQL distributed database

TiDB 2.1.17 has been released, updated as follows:

• New features

  • TiDB the  SHOW TABLE REGIONS syntax new  WHERE conditional clause
  • TiKV, PD new  config-check features for configuring Checker
  • pd-ctl new  remove-tomestone commands, support clean-up tombstone store records
  • Reparo new  worker-count and  txn-batch configuration item, for controlling the rate of recovery

• Improved upgrade

  • PD optimize the scheduling process, support the initiative to dispatch issued
  • TiKV optimize the boot process, reduce the jitter caused by restarting node

• Behavior change

  • TiDB slow the log  start ts from the last time to retry execution time of the first
  • TiDB slow log  Index_ids field is replaced with  Index_names the field, to enhance ease of use slow log
  • Add TiDB profile  split-region-max-num parameters for adjusting the  SPLIT TABLE maximum allowable number Region grammar, the default configuration, allowing the number increased from 1,000 to 10,000

TiDB

• SQL optimizer
  • Repair  EvalSubquery the building  Executor when an error occurs, the error message is not returned right questions  # 11811
  • Index Lookup Join repair, the number of rows in the appearance of more than one batch, the results of the query may not be the right questions; expand the scope Index Lookup Join: You can use  UnionScan as  IndexJoin child nodes  # 11843
  • Key's possible failure of the feedback process for the case of statistical information, SHOW STAT_BUCKETS the statement now adds Key's failure, for example: invalid encoded key flag 252 # 12098
• SQL execution engine
  • Repair  CAST when numeric type conversion function during the first converts a value to  UINT cause some problems incorrect results (for example, select cast(13835058000000000000 as double)) # 11712
  • Repair  DIV operation dividend for the  DECIMAL type and operational issues contain negative, the operation result may be incorrect  # 11812
  • Add  ConvertStrToIntStrict function to perform repair  SELECT/ EXPLAIN when the statement, some of the string conversion  INT problems result type is not compatible with MySQL  # 11892
  • Repair using  EXPLAIN ... FOR CONNECTION syntax, stmtCtx not set up properly cause  Explain the results may not be the right questions  # 11978
  • Repair  unaryMinus function, when Int result overflows, returns the result type is not compatible with MySQL did not lead to problems for the Decimal  # 11990
  • Repair  LOAD DATA statement is executed, the count sequence caused by  last_insert_id() possible incorrect question  # 11994
  • Repair user explicitly, implicitly written from mixing additional data last_insert_id() may be incorrect question  # 12001
  • Repair a  JSON_UNQUOTE function compatibility problem: only in double quotes ( "value) within the required Unquote, for example,  SELECT JSON_UNQUOTE("\\\\") should be " \\" (without Unquote) # 12096
• Server
  • When TiDB retry the transaction, recorded in the slow log  start ts the last retry time was changed to the time of the first performance  # 11878
  • In  LockResolver the number of transactions Key added: when the number of Key, avoid the entire Region of Scan operations, reduce the cost of clearing the lock  # 11889
  • Repair slow logs, succ field values may be incorrect question  # 11886
  • The slow log  Index_ids field is replaced with  Index_names the field, to enhance ease of use slow log  # 12063
  • Repair  Duration contained in the content  - (for example  select time(‘--’)), TiDB resolved to disconnect EOF Error cause errors  # 11910
  • Improvement  RegionCache: Region When a failure, it will be faster from the  RegionCache removal of, reducing the number of requests sent to the Region  # 11931
  • Repair  oom-action = "cancel" time, when  Insert Into … Select a problem occurs statement OOM, OOM Panic are not correctly handled resulting in disconnected  # 12126
• DDL
  • Is  tikvSnapshot added reverse scan interface for efficient query DDL History Job, after use of the interface  ADMIN SHOW DDL JOBS execution time significantly decreased  # 11789
  • Improved  CREATE TABLE ... PRE_SPLIT_REGION semantics: when the specified  PRE_SPLIT_REGION = N number of Region, the pre-segmentation by 2 ^ (N-1) to N ^ 2  # 11797
  • According to the impact load test each other online and Add Index , adjust the default parameters small Add Index background worker threads to avoid greater impact on the load line  # 11875
  • Improved  SPLIT TABLE syntax behavior: When used  SPLIT TABLE ... REGIONS N for cutting division Region, generates N data and an index Region Region  # 11929
  • Add the profile  split-region-max-num parameters, so  SPLIT TABLE the maximum number of Region syntax allows adjustable, the default value of the parameter  10000 # 12080
  • Repair write binlog, CREATE TABLE the statement in  PRE_SPLIT_REGIONS part is not annotated, resulting statement can not be resolved the problem downstream MySQL  # 12121
  • SHOW TABLE … REGIONS And  SHOW TABLE .. INDEX … REGIONS syntax of new  WHERE conditional clause  # 12124
• Monitor
  • Increased monitoring indicators  connection_transient_failure_count, statistics for  tikvclient the number of errors connected gRPC  # 12092

TiKV

• Region solve the problem within the key number in some cases inaccurate statistics  # 5415
• TiKV new  config-check option for checking the legality of TiKV configuration item  # 5391
• Start optimizing processes, reducing jitter caused by restarting node  # 5277
• Optimization process to unlock some cases, accelerate transaction unlock  # 5339
• Optimization  get_txn_commit_info of processes, accelerate transaction commit  # 5062
• Simplify Raft related log  # 5425
• To solve the problem in some cases TiKV abnormal exit  # 5441

PD

• PD new  config-check option for checking the legality of PD configuration item  # 1725
• pd-ctl new  remove-tomestone commands, support clean-up tombstone store record  # 1705
• Support actively delivers Operator, accelerate the speed of dispatch  # 1686

Tools

• TiDB Binlog

  • Reparo new  worker-count and  txn-batch configuration items used to control the rate of recovery  # 746
  • Drainer optimize memory usage, improve efficiency synchronous execution  # 735
  • Pump repair offline sometimes not normal bug  # 739
  • Pump optimization LevelDB processing logic to enhance the efficiency of GC  # 720

• TiDB Lightning

  • Repair reimported from the checkpoint point could lead to the collapse of tidb-lightning bug  # 239

TiDB Ansible

• Spark update version 2.4.3, and update TiSpark is compatible with version 2.2.0 of the Spark of  # 914 , # 919
• Fixed an issue when the password expires remote machine connected for long periods of waiting  # 937 , # 948

Release Notes: https://pingcap.com/docs-cn/v3.0/releases/2.1.17/