DevOps Articles

Speeding up our Rails apps with asynchronous cache writes

At carwow our applications can be chatty, making one or several API calls to each other in order to fulfil a request. In fact, around 48% of all user-facing requests in the last 7 days made at least one API request to another one of our applications before responding. One of the tools we use to reduce the strain we put between our applications is caching.

Something I’ve learned to do during optimisation work is to think of all the changes we intend to make as experiments, and that means taking a lot of measurements.

To test the effectiveness of this change we rolled it out to 50% of our application servers and had a look at overall performance impact on web requests.