How Does Alibaba Cloud Power the Biggest Online Shopping Festival?

Designing a High Availability Infrastructure

As the Architect for Single’s Day since 2009, I will share with you some of our key strategies in designing our infrastructure.

Comprehensive Load Testing on System Architecture

Load testing is one of the default metric for performance testing in most systems. Basically, what we do is to simulate the traffic load of Single’s Day and test it on our existing infrastructure. We use traffic data collected from previous years as well as predicted data to account for this year’s growth. One of the important purpose of load testing is not only to discover the maximum capacity but also to determine the most common applications and services that customers use during this period.

System Architecture Fault Simulation

Essentially, fault simulation is a form of stress testing on our system architecture. We intentionally disable certain services, overloading the system with heavy loads. In particular, we look out for any Single-Point-of-Failures (SPOFs) in our architecture and eliminate them.

Cross-Region Server Deployment

In most scenarios, servers only run within a single region. However, this approach may not be sufficient when faced with extreme loads during Single’s Day. Therefore, we utilize cross-region deployment to expand the capacity and improve service availability. We split users into different servers based on user ID, and employ an active-active configuration in our clusters to maintain high availability and achieve seamless service handover. In addition, data is also backed up across multiple sites to enhance disaster recovery capabilities.

Automated Intelligent Control

Even with all of the technologies discussed previously, it is almost impossible to control traffic flow and scale resources in a large system manually. That is why we use an automated intelligent control, which focuses on traffic control and fault recovery.


As we can see, powering an event as large as Single’s Day is no easy task. With proper planning and design, we can cope even the most unexpected challenges for this event. We are confident that our evolved architecture can achieve a lot more for this year’s Single’s Day festival!



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