Run EXPLAIN on Wikimedia Toolforge SQL queries

https://sql-optimizer.toolforge.org

You can report bugs or make feature requests by filing an issue on GitHub: https://github.com/MusikAnimal/sql-optimizer/issues

Or you can use on Wikimedia's Phabricator. Please tag with the Tools project and add MusikAnimal as a subscriber.

Prerequisites:

• Node.js with the version specified by .nvmrc.
• npm
• A Wikimedia developer account and access to the Toolforge environment.

Installation:

• git clone https://github.com/MusikAnimal/sql-optimizer

• cd sql-optimizer

• npm install

• Establish an SSH tunnel to the Toolforge replicas. It is important to connect to a specific database server. The command will be something similar to:

  ssh -L 4711:enwiki.web.db.svc.eqiad.wmflabs:3306 [email protected]
  

• cp env.json.dist env.json and fill out the details. In the above example, the db_port would be 4711.

• npm run-script build && npm run-script start - note you will need to re-run this command as you make changes during development.

• You should be up and running at http://localhost:8000

• Note you can only query against the database you set up in your SSH tunnel (enwiki in the above example). In production, the host in env.json is set to *.web.db.svc.eqiad.wmflabs which gets changed to the appropriate host for the given database at run time.