2017-06-05-tidb-weekly.md

title	date	summary	tags
Weekly update (May 22 ~ June 05, 2017)	2017-06-05	Last two weeks, we landed 53 PRs in the TiDB repositories and 33 PRs in the TiKV repositories.	TiDB TiKV

Weekly update in TiDB

Last two weeks, we landed 53 PRs in the TiDB repositories.

Added

• Support using After and First to specify column position in the Alter Table Statement.

• Support the password builtin function.

• Support the inet6_ntoa builtin function.

• Support the Extract and Unquote function for Json.

• Support json_{set/insert/replace} and json_merge for Json.

• Support batched Index Lookup Join.

Fixed

• Fix a goroutine leak problem.

• Fix a bug in double read executor.

• Fix a bug for type inferrer of Bit literal value.

• Fix a bug about context cancellation.

Improved

• Refactor expression evaluation:

  • Refactor the cast function.
  • Add the GetTypeClass() interface in Expression.

• Update stored password in mysql.user table to make it consistent with MySQL.

• Speed up the DDL process:

  • Use etcd to synchronise schema version instead of waiting two leases.
  • Enable DDL speed up.

• Add the references_priv column in mysql.user.

• Close DDL worker gracefully when shutting down the TiDB server.

Weekly update in TiKV

Last two weeks, We landed 33 PRs in the TiKV repositories.

Added

• Introduce gRPC, see 1850, 1865, 1868, 1879.
• Report the written keys to PD for better scheduler.
• Balance the hot regions by peer and leader together.
• Record the cluster bootstrap time.
• Add the state for operators.
• Add the metrics for balance.
• Add the disaster recovery tool for PD.
• Output the allocation statistics when receiving SIGUSR1.
• Add the direct IO configuration for RocksDB.

Fixed

• Check the cluster ID when re-connecting to PD.
• Reuse the timer to avoid spawning thread frequently.
• Remove the realtime signal handler.
• Prevent accessing nil store when recovering cluster.
• Check the environment TZ setting.
• Use the forward mode for scanning data in GC command.
• Check the last apply index to determine handing snapshot.

Improved

• Increase the region size from 64 MB to 96 MB.
• Split total region peer cache.
• Use FlatMap instead of HashMap to improve performance.
• Modify the default compression in RocksDB.