EC2 Placement Groups: Cluster vs Spread vs Partition.

In Simple Words:

• Cluster: Packs instances together in a single AZ for ultra-low latency and 100 Gbps network throughput.
• Spread: Places each instance on distinct physical hardware racks to prevent correlated hardware failures.
• Partition: Spreads instances across logical partitions that don't share racks (ideal for HDFS, Kafka, Cassandra).

resource "aws_placement_group" "hpc_cluster" {
  name     = "hpc-cluster-group"
  strategy = "cluster"
}