TiDB Introduction

1. TiDB: Distributed, horizontally
scalable, MySQL compatible
FOSDEM 2019
Morgan Tocker (@morgo)

2. Agenda
● History and Community
● Technical Walkthrough
● Use Cases
● Benchmarks
● MySQL Compatibility

3. History and Community #singlepage
Founded in 2015 in China
Ti = Titanium
Apache 2.0 Licensed
Storage layer (TiKV) a CNCF project since 2018
US Office since 2018
Quick Numbers:
700+ Annual Conference Attendees
300+ Production Deployments
200+ GitHub Contributors (the TiDB server alone)

4. Agenda
● History and Community
● Technical Walkthrough
● Use Cases
● Benchmarks
● MySQL Compatibility

5. Introduction
TiDB is a distributed database that speaks the MySQL protocol
It is not based on the MySQL source code
It is an ACID/strongly consistent database
The inspiration is Google Spanner/F1
It separates SQL processing and Storage into separate components
Both of them are independently scalable
The SQL processing layer is stateless
It is designed for both Transaction and Analytical Processing (HTAP)

6. TiDB
TiDB
Region 1 L
TiKV Node 1
Region 2
Region 3
Region 4
Region 2 L
TiKVNode 3
Region 3
Region 4 L
Region 1
Region 4
TiKV Node 2
Region 3 L
Region 2
Region 1
TiKV Cluster
PD Cluster

7. Row + Column Storage (Announced Jan 2019)
Spark Cluster
TiDB
TiDB
Region 1
TiKV Node 1
Region 2
Region 3
Region 4
Region 2
TiKV Node 3
Region 3
Region 4
Region 1
Region 4
TiKV Node 2
Region 3
Region 2
Region 1
TiFlash Node 2
TiFlash Extension Cluster TiKV Cluster
TiSpark
Worker
TiSpark
Worker
TiFlash Node 1

8. TiDB: The SQL Layer
Node1 Node2 Node3 Node4
MySQL Network Protocol
SQL Parser
Cost-based Optimizer
Distributed Executor (Coprocessor)
ODBC/JDBC MySQL Client
Any ORM which
supports MySQL
TiDB
TiKV

9. TiKV: The Storage Foundation
RocksDB
Raft
Transaction
Txn KV API
Coprocessor
API
RocksDB
Raft
Transaction
Txn KV API
Coprocessor
API
RocksDB
Raft
Transaction
Txn KV API
Coprocessor
API
Raft
Group
Client
gRPC
TiKV Instance TiKV Instance TiKV Instance
gRPC gRPC
PD Cluster

10. Migration (in and out of TiDB)
DM
MySQL Binlog
SQL Dump File
Lightning
TiDB
Binlog
MySQL
Instances

11. Agenda
● History and Community
● Technical Walkthrough
● Use Cases
● Benchmarks
● MySQL Compatibility

12. Use Cases
1. Approaching the maximum size for MySQL
on a single server. Debating whether or not
to shard.
2. Already sharded MySQL, but having a hard
time doing analytics on up-to-date data.

13. Mobike + TiDB
● 200 million users
● 200 cities
● 9 million smart bikes
● ~30 TB / day

14. Agenda
● History and Community
● Technical Walkthrough
● Use Cases
● Benchmarks
● MySQL Compatibility

15. Benchmarks (TiDB 2.1) Thank you Alexander Rubin!
https://www.percona.com/blog/2019/01/24/a-quick-look-into-tidb-performance-on-a-single-server/

16. Benchmarks (TiDB 2.1) Thank you Alexander Rubin!
https://www.percona.com/blog/2019/01/24/a-quick-look-into-tidb-performance-on-a-single-server/

17. Benchmarks (TiDB 2.1) Thank you Alexander Rubin!
https://www.percona.com/blog/2019/01/24/a-quick-look-into-tidb-performance-on-a-single-server/

18. Agenda
● History and Community
● Technical Walkthrough
● Use Cases
● Benchmarks
● MySQL Compatibility

19. pingcap.com
/docs/sql/mysql-compatibility/

21. Summary
● Compatibility with MySQL 5.7:
○ Joins, subqueries, DML, DDL etc.
○ All SQL Modes
● On the 3.0 roadmap:
○ CTEs, Views, Window Functions
● Not Planned:
○ Stored Procedures, Triggers, Events, Fulltext

22. Nuanced
● Some features work differently
○ Auto Increment
○ Optimistic Locking
● TiDB works better with smaller transactions
○ Recommended to batch updates, deletes,
inserts to 5000 rows

23. Tools
● Mydumper, ProxySQL work
○ We maintain a branch of mydumper
○ We are looking to push upstream
● Innotop.. won’t work
● MySQL Workbench works!

24. Thank you!