How do EC2 placement groups help optimize instance performance for specific networking or availability requirements?

EC2 placement groups let you influence how your instances are physically placed on underlying hardware, with a cluster placement group packing instances close together within a single Availability Zone for the lowest possible network latency between them, a spread placement group placing instances on distinct underlying hardware to minimize the risk of correlated hardware failures affecting multiple instances at once, and a partition placement group grouping instances into logical partitions that do not share underlying hardware, useful for distributed systems like Hadoop that need to isolate failure domains.

aws ec2 create-placement-group --group-name my-cluster-group --strategy cluster