Explore Vitess

Why do we need Vitess

MySQL does not have a good support of sharding, re-sharding, routing.(MySQL cluster is not open source). In addition, the performance of purely using MySQL is low: Client needs to establish connection for each query.

Architecture

• Topology Service:
  • It enables tablets to coordinate among themselves as a cluster.(A coordinator).
  • It enables Vitess to discover tablets, so it knows where to route queries.(For service discovery).
  • It stores Vitess configuration provided by the database administrator that is needed by many different servers in the cluster, and that must persist between server restarts.(For disaster recovery).
• VTGate: Stateless proxy to route queries.
• VTTablet: Daemon agent running along with mysqld on the same machine.

Try Vitess Operator on K8S

https://vitess.io/docs/get-started/operator/

Pros and Cons

Pros

• Query rewrite.
• Sharding mgmt for MySQL.
• Plug-in model for supporting topology service(Distributed lock manager, Repository for topology metadata): ETCD, ZooKeeper, Consul

Cons

• Migration is painful because you have to modify schema.

References

• Vitess Architecture
• Tech meetup: Vitess(Chinese version)
• Slack scale MySQL with Vitess
• Linkedin scale MySQL with Vitess
• Vitess at HubSpot