Vitess

Vitess is a set of servers and tools meant to facilitate scaling of MySQL databases for the web. It's currently used as a fundamental component of YouTube's MySQL infrastructure.

sougou presented Vitess at Fosdem '14 in the go devroom. Here are the slides, and here is the video.

Vitess is currently not ready for unsupervised use yet. There's good deal of documentation missing. Also, some functionality is under development and some APIs are still changing. But if you feel adventurous, you're welcome to try it. If you run into issues, please subscribe and post to our mailing list. We'll do our best to help you.

• Vision
• Concepts
• General Concepts
• Replication Graph
• Serving graph
• Tools
• Getting Started
• Operations
• Preparing for production
• Reparenting
• Resharding
• Schema management
• Zookeeper data

vttablet

TODO: Move this content to its own markdown.

Smart middleware sitting in front of MySQL and serving clients requests.

• Connection pooling.
• SQL parser: Although very close, the vtocc SQL parser is not SQL-92 compliant. It has left out constructs that are deemed uncommon or OLTP-unfriendly. It should, however, allow most queries used by a well-behaved web application.
• Query rewrite and sanitation (adding limits, avoiding non-deterministic updates).
• Query consolidation: reuse the results of an in-flight query to any subsequent requests that were received while the query was still executing.
• Rowcache: the mysql buffer cache is optimized for range scans over indices and tables. Unfortunately, it’s not good for random access by primary key. The rowcache will instead maintain a row based cache (using memcached as its backend) and keep it consistent by fielding all DMLs that could potentially affect them.
• Update stream: A server that streams the list of rows that are changing in the database, which can be used as a mechanism to continuously export the data to another data store.
• Integrated query killer for queries that take too long to return data.
• Discard idle backend connections to avoid offline db errors.
• Transaction management: Ability to limit the number of concurrent transactions and manage deadlines.

License

Unless otherwise noted, the vitess source files are distributed under the BSD-style license found in the LICENSE file.