Introducing schemadiff, an internal library in Vitess that has been one of its best-kept secrets until now. At its core, schemadiff is a declarative, programmatic library that can produce a diff in SQL format of two entities: tables, views, or full blown database schemas. But it then goes beyond that to normalize, validate, export, and even apply schema changes, all declaratively and without having to use a MySQL server. Let's dive in to understand its functionality and capabilities.

Note: The content was originally published at PlanetScale Connection pooling is a commonly used technique in modern applications to manage database connections efficiently. It involves creating a cache of database connections that the application can use as needed. Instead of creating a new connection for each request to the database, the application retrieves a connection from the pool. After the application finishes using the connection, it is returned to the pool to be reused later, rather than being closed outright.

We are pleased to announce the general availability of Vitess 16! Documentation improvements # In this release the maintainer team has decided to put an emphasis on reviewing, editing, and rewriting the website documentation to be current with the code. With help from CNCF, we have also improved the search experience. We welcome feedback on the current incarnation of the docs. GA announcements # We are marking VDiff v2 as Generally Available or production-ready in v16.

Some of the Vitess maintainers traveled to Brussels, Belgium to attend and speak at pre-FOSDEM MySQL Days and at FOSDEM. pre-FOSDEM MySQL Days # When: Feb 2-3 Who: Deepthi Sigireddi, Harshit Gangal, Shlomi Noach What: VTOrc - How Vitess achieves consensus using MySQL Replication by Deepthi Highlights # There were a lot of questions about how Vitess handles various failure scenarios. We had good conversations with both the MySQL team and MySQL/Vitess community users.

Vitess 15 is now generally available, with a number of new enhancements designed to make Vitess easier to use, more resilient, and easier to scale! VTOrc release # VTOrc, a Vitess-native cluster monitoring and recovery component, is now GA. VTOrc monitors and repairs Vitess clusters, eliminating paging and manual intervention and automating recovery. This makes Vitess fully self-healing and resilient to MySQL server failures. It also obsoletes the third-party integration with Orchestrator that users have traditionally relied on to recover from MySQL server failures.

There was an idea. An idea to make Vitess self-reliant. An idea to get rid of the friction between Vitess and external fault-detection-and-repair tools. An idea that gave birth to VTOrc… Both VTOrc and Orchestrator are tools for managing MySQL instances. If I were to describe these tools using a metaphor, I would say that they are kinda like the monitor of a class of students. They are responsible for keeping the MySQL instances in check and fixing them up in case they misbehave, just like how a monitor ensures that no mischief happens in the classroom.

Introduction # MySQL group replication is a new replication mechanism that was released in 2016. Group replication involves establishing a group of nodes that are coordinated automatically via Group Communication System (GCS) protocols, an implementation of Paxos. For a transaction to commit, a majority of the group has to agree on the order of a given transaction in the global sequence of transactions. Deciding to commit or abort a transaction is done by each server individually, but all servers make the same decision.

We are pleased to announce the general availability of Vitess 14. Major Themes # In this new release, major improvements have been made in several areas of Vitess, including usability and reliability. Online DDL is now GA. Gen4 planner is the new default planner. VTAdmin and VTOrc are officially in beta with Vitess 14. Usability # Command-Line Syntax Deprecation # This release marks the beginning of Vitess standardizing its command-line and flags syntax.

Kubecon+CloudNativeCon EU 2022 # When: May 16-20 Who: Deepthi Sigireddi, Harshit Gangal, Manan Gupta What: Vitess project booth, maintainer talk, office hours Event Details # May 16-17 were co-located events. We were there for the main conference which was May 18-20. There were 7000+ attendees. The Vitess team were attending in their capacity as project maintainers to staff a booth in the Project Pavilion, hold office hours and to give a talk.

Vitess supports managed, non-blocking schema migrations based on VReplication, aptly named vitess migrations. Vitess migrations are powerful, revertible, and failure agnostic. They take an asynchronous approach, which is more lightweight on the database server. The asynchronous approach comes with an implementation challenge: how to cut-over with minimal impact to the user/app and risk free of data loss. In this post we take a deep dive into the cut-over logic used in vitess migrations.