The physical placement of AWS EC2 instances can be influenced by an assigned placement strategy.
At the time of writing, AWS offers three:
- Cluster
- Within a single AZ
- Low latency, high throughput
- Rack or AZ become single points of failure
- Partition
- Distributes instances across multiple racks in different AZs
- Better fault tolerance
- Worse network performance
- Spread
- In between cluster and partition
- Different racks within a single AZ