TiDB-The Daily Ledger

TiDB (/’taɪdiːbi:/, "Ti" stands for Titanium) is an open-source NewSQL database that supports Hybrid Transactional and Analytical Processing (HTAP) workloads. It is MySQL compatible and can provide horizontal scalability, strong consistency, and high availability. It is developed and supported primarily by PingCAP and licensed under Apache 2.0. TiDB drew its initial design inspiration from Google's Spanner and F1 papers.

Release history

See all TiDB release notes. On April 7, 2022, TiDB 6.0 GA was released. On April 7, 2021 TiDB 5.0 GA was released. On May 28, 2020, TiDB 4.0 GA was released. Its key features include: TiFlash, TiDB Dashboard (experimental), TiUP, pessimistic transactions, cascading placement rules (experimental), elastic scheduling (experimental), large transactions, new SQL features, case-insensitive and accent-insensitive `utf8mb4_general_ci` and `utf8_general_ci` collations, improved encrypted communication, Transparent Data Encryption (TDE), Backup & Restore, Coprocessor Cache (experimental), Follower Read, and TiCDC (experimental). On June 28, 2019, TiDB 3.0 GA was released. On April 27, 2018, TiDB 2.0 GA was released. On October 16, 2017, TiDB 1.0 GA was released.

TiDB

Main features

Horizontal scalability

TiDB can expand both SQL processing and storage capacity by adding new nodes. This makes infrastructure capacity scaling easier and more flexible compared to traditional relational databases which only scale vertically.

TiDB

MySQL compatibility

TiDB acts like it is a MySQL 5.7 server to applications. A user can continue to use all of the existing MySQL client libraries. Because TiDB's SQL processing layer is built from scratch, not a MySQL fork, its compatibility is not 100%, and there are known behavior differences between MySQL and TiDB.

TiDB

Distributed transactions with strong consistency

TiDB internally shards a table into small range-based chunks that are referred to as "Regions". Each Region defaults to approximately 100 MB in size, and TiDB uses a two-phase commit internally to ensure that regions are maintained in a transactionally consistent way.

Cloud native

TiDB is designed to work in the cloud to make deployment, provisioning, operations, and maintenance flexible. The storage layer of TiDB, called TiKV, became a Cloud Native Computing Foundation (CNCF) member project in August 2018, as a Sandbox level project, and became an incubation-level hosted project in May 2019. TiKV graduated from CNCF in September 2020. The architecture of the TiDB platform also allows SQL processing and storage to be scaled independently of each other.

Real-time HTAP

TiDB can support both online transaction processing (OLTP) and online analytical processing (OLAP) workloads. TiDB has two storage engines: TiKV, a rowstore, and TiFlash, a columnstore. Data can be replicated from TiKV to TiFlash in real time to ensure that TiFlash processes the latest data.

High availability

TiDB uses the Raft consensus algorithm to ensure that data is highly available and safely replicated throughout storage in Raft groups. In the event of failure, a Raft group will automatically elect a new leader for the failed member, and self-heal the TiDB cluster without any required manual intervention. Failure and self-healing operations are transparent to the applications.

Deployment methods

Kubernetes with Operator

TiDB can be deployed in a Kubernetes-enabled cloud environment by using TiDB Operator. An Operator is a method of packaging, deploying, and managing a Kubernetes application. It is designed for running stateful workloads and was first introduced by CoreOS in 2016. TiDB Operator was originally developed by PingCAP and open-sourced in August, 2018. TiDB Operator can be used to deploy TiDB on a laptop, Google Cloud Platform’s Google Kubernetes Engine, and Amazon Web Services’ Elastic Container Service for Kubernetes.

TiUP

TiDB 4.0 introduces TiUP, a cluster operation and maintenance tool. It helps users quickly install and configure a TiDB cluster with a few commands.

TiDB Ansible

TiDB can be deployed using Ansible by using a TiDB Ansible playbook (not recommended).

Docker

Docker can be used to deploy TiDB in a containerized environment on multiple nodes and multiple machines, and Docker Compose can be used to deploy TiDB with a single command for testing purposes.