TiDB Weekly

News & blog post

In TiDB 3.1 Beta released on Dec 20, 2019, TiDB introduced Follower Read, a highlight open-source feature that lets any follower replica in a Region serve a read request under the premise of strongly consistent reads. This feature improves the throughput of the TiDB cluster and reduces the load on the Raft leader.

Last week, we published a post that guides you through why we introduced Follower Read, how we implement it, and our future plans for it.

The full post is here:

Doubling System Read Throughput with Only 26 Lines of Code

Community

New contributors

tidb:

• hg2990656

tikv:

• xinhua5

Call for participation

• Issues to solve for TiDB
• Issues to solve for TiKV

Updates of the week

Progress

Last week, we landed 64 PRs in the TiDB repository, 3 PRs in the TiSpark repository, and 33 PRs in the TiKV and PD repositories.

Critical PRs

TiDB:

• Fully Enable the CAST push-down switcher
• Cache the point get result
• Fix the issue that lower()/upper() does not work if a string contains the utf8 character
• Merge overlapped ranges when building key ranges for indexJoin
• Support recording the rejected connection attempts in the audit log
• Update information_schema.tables to support AUTO_RANDOM
• Add the implementation rule for LogicalMemTable in the cascades planner
• Add TiKV metric tables
• Improve the concurrency of statement summary
• Count the number of Hash table collisions and build Elapse during Hash Join
• Improve the performance of WindowExec by using the sliding window
• Add the built-in json_objectagg aggregate function

TiSpark:

• Fix the CHblock decoding bug
• Enable the key ranges for the TiFlash dag request
• Fix the TiFlash Region cache

TiKV and PD:

• Fix builds on macOS
• Fix the issue that the yyyy-mm-dd HH:MM:SS format cannot be parsed to Duration
• Introduce the Pre-transfer Leader feature
• Support Yield for apply
• Add a benchmark for the batch system
• Add the CDC delegate
• Implement Initializer of CDC's Endpoint
• Optimize ChunkEncoder
• Support backing up the raw key-value pairs
• Store the placement rules in separated key-values pairs
• Add operator Influence when sorting stores
• Make the original HTTP API compatible with the configuration manager

Upcoming TiDB event

Infra Meetup No.124 (online) (in Chinese)

Date: February 15th, 2020