TiDB 2.0.1 Release Notes

On May 16, 2018, TiDB 2.0.1 is released. Compared with TiDB 2.0.0 (GA), this release has great improvement in MySQL compatibility and system stability.

TiDB

Update the progress of Add Index to the DDL job information in real time
Add the tidb_auto_analyze_ratio session variable to control the threshold value of automatic statistics update
Fix an issue that not all residual states are cleaned up when the transaction commit fails
Fix a bug about adding indexes in some conditions
Fix the correctness related issue when DDL modifies surface operations in some concurrent scenarios
Fix a bug that the result of LIMIT is incorrect in some conditions
Fix a capitalization issue of the ADMIN CHECK INDEX statement to make its index name case insensitive
Fix a compatibility issue of the UNION statement
Fix a compatibility issue when inserting data of TIME type
Fix a goroutine leak issue caused by copIteratorTaskSender in some conditions
Add an option for TiDB to control the behaviour of Binlog failure
Refactor the Coprocessor slow log to distinguish between the scenario of tasks with long processing time and long waiting time
Log nothing when meeting MySQL protocol handshake error, to avoid too many logs caused by the load balancer Keep Alive mechanism
Refine the “Out of range value for column” error message
Fix a bug when there is a subquery in an Update statement
Change the behaviour of handling SIGTERM, and do not wait for all queries to terminate anymore

PD

Add the Scatter Range scheduler to balance Regions with the specified key range
Optimize the scheduling of Merge Region to prevent the newly split Region from being merged
Add Learner related metrics
Fix the issue that the scheduler is mistakenly deleted after restart
Fix the error that occurs when parsing the configuration file
Fix the issue that the etcd leader and the PD leader are not replicated
Fix the issue that Learner still appears after it is closed
Fix the issue that Regions fail to load because the packet size is too large

TiKV

Fix the issue that SELECT FOR UPDATE prevents others from reading
Optimize the slow query log
Reduce the number of thread_yield calls
Fix the bug that raftstore is accidentally blocked when generating the snapshot
Fix the issue that Learner cannot be successfully elected in special conditions
Fix the issue that split might cause dirty read in extreme conditions
Correct the default value of the read thread pool configuration
Speed up Delete Range