EC2 Placement Groups
Placement groups allow you to define where your EC2 instances are deployed on AWS infrastructure.
A placement group is either:
- A cluster: puts your instances in a low latency group in the same AZ. This helps with networking as instances are close to one another. Drawback is if the AZ fails, they all fail. use case: Good for big data jobs, apps that need low latency between instances.
- Spread: Think of this as opposite to clusters. Each instance is on different hardware across different AZs. This means reduced failure risk. Limited to 7 AZ per placement group. Use case: maximum high availability.
- Partition: spreads instances across different partitions within an AZ. Each partition represents a rack in AWS. Instances are distributed across different hardware racks and AZs in same region. use cases: Big data application, which are petition aware.
