placementGroup

The Amazon EC2 placement group to associate with your compute resources. If you intend to submit multi-node parallel jobs to your compute environment, you should consider creating a cluster placement group and associate it with your compute resources. This keeps your multi-node parallel job on a logical grouping of instances within a single Availability Zone with high network flow potential. For more information, see Placement groups in the Amazon EC2 User Guide for Linux Instances . When updating a compute environment, changing the placement group requires an infrastructure update of the compute environment. For more information, see Updating compute environments in the AWS Batch User Guide .

This parameter isn't applicable to jobs that are running on Fargate resources. Don't specify it.