Squid game: how we load-tested Ably’s Control API

The Control API is a new feature from Ably that enables users to manage configurations programmatically. It has been designed with dependability in mind, adhering to four pillars of reliability: Performance, Integrity, Reliability, and Availability. To ensure its robustness under heavy load, the Control API was subjected to rigorous load testing using Apache JMeter and Locust. The tests aimed to simulate realistic usage patterns from various types of users, including typical, power, bad, and bot users. Rate-limiting issues were addressed by using Squid proxy to forward requests from different IPs. Resources for managing the load testing system were closely monitored to prevent excessive costs. Overall, the Control API's performance under heavy load was satisfactory, providing confidence in its ability to handle real-world usage scenarios.