AWS::EC2::PlacementGroup

• Set where ec2 instances will be provisioned
• Placements groups are created separately and associated with a EC2 instance at its creation

Properties

• https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-ec2-placementgroup.html

Strategy

• cluster (high performance): deploy to same rack (and same AZ). High performance + High risk. Good for HPC. 10 Gbps network

• spread (high availability): deploy to different racks (at most one instance per rack) across different AZ's (in the same region). Limited to 7 instances per AZ

• partition (balanced): deploy to the same rack (and same AZ), but they are replicated to other racks (and other AZs) as a backup. The number of partitions define the number of replicas. Use case for HDFS, HBase, Cassandra, Kafka