Yelp Product & Engineering Blog

tron - Centralized Scheduling

As Yelp has grown over the years, we've amassed huge collections of data - the collective output of the actions of tens of millions of users. Analyzing this data helps us improve the user experience across the site, from ranking businesses and extracting "review highlights" to fighting spam and keeping the site secure. These tasks involve long-running batch processes that analyze large logs and database tables, with workflows sometimes composed of five or more dependent processes. Managing these workflows with traditional scheduling tools - most notably the cron family - eventually caused us to breach the "complexity comfort zone" that surrounds any large engineering project. But then we had a vision, and it is that vision we are releasing today as tron.

Push it!

At Yelp, we push new code live every day. Pushing daily allows us to quickly prototype new features and squash bugs in a proactive manner. Because we aim to deploy new code so often, we're always looking for ways to make the process efficient and painless.

There are four main stages to the Yelp push process: code review, integration, testing, and finally, live deployment. Each step is important, and there are ways to maximize the efficiency of all of them.