Final answer:
To design systems that are fault-tolerant, three AWS features that help in supporting this principle are Availability Zones for geographic isolation and fault tolerance, Elastic Load Balancer for traffic distribution and increased fault tolerance, and Regions for deploying applications to ensure availability despite regional failures.
Step-by-step explanation:
In the context of Amazon Web Services (AWS), the principle of "design for failure and nothing will fail" is about creating systems that are resilient to failures by accounting for potential faults and automating recovery processes. To support this design principle, AWS offers several services and features:
- Availability Zones: These are distinct locations within a region that are engineered to be isolated from failures in other Availability Zones. They offer the ability to operate production applications and databases that are more highly available, fault tolerant, and scalable than would be possible from a single data center.
- Elastic Load Balancer (ELB): ELB automatically distributes incoming application traffic across multiple targets, such as Amazon EC2 instances, containers, and IP addresses. It can handle the varying load of your application traffic in a single Availability Zone or across multiple Availability Zones.
- Regions: AWS has the concept of Regions, which refer to separate geographic areas. Running applications in multiple regions can provide better latency to end users and help ensure that applications remain available even if a disaster affects an entire region.
When using Availability Zones and Regions, an application can be designed to failover to another zone or region in case of an outage, ensuring high availability. The Elastic Load Balancer helps to achieve a level of fault tolerance within the application architecture by distributing traffic and reducing the impact of a failure on a single instance or endpoint.