Multi-region serverless backend — reloaded
Accelerating Serverless Applications with Global Accelerator and Application Load Balancer
In 2018, I wrote a series of blog posts on building a multi-region, active-active, serverless architecture on AWS [1, 2, 3 and 4]. The solution was built using DynamoDB Global Tables, Lambda, the regional API Gateway feature, and Route 53 routing policies. It worked well as a resiliency pattern and as a disaster recovery (DR) strategy . But there was an issue.
Brace yourself: DNS isn’t perfect
DNS is one of the most important services on the Internet as it turns a user-friendly domain name like amazon.com into an IP address that computers use to identify each other and direct traffic to a network.
To do so, the DNS service uses a hierarchy of name servers distributed around the world that try to answer a simple question: “what is the IP for that particular domain name?” If a name server cannot answer the question, it may query another name server higher in the hierarchy. This process is called recursive query.
