Placement Groups

When several EC2 instances are launched, AWS offers to distribute the instances physically such that it can reduce the number of system crashes, thus offering high availability. However, this can be troublesome when instances require low-latency communication. Imagine a group of instances that require constant low-latency and high throughput communication to offer services to the users, and each instance is deployed on a different physical structure in an AZ. To cater to such issues, Amazon EC2 also offers placement groups.

A placement group allows control of the deployment of interdependent instances across the underlying infrastructure. Placement groups are purposely designed to meet our workload requirements.

Let’s take a deeper look into different placement strategies and their benefits.

Types of placement groups

EC2 offers different placement groups to cater to various application needs related to performance, availability, and fault tolerance. Each placement group offers flexibility to arrange instances as per the needs. Let’s take a look at them in detail. 

Cluster placement group

The cluster placement group is a logical grouping of interrelated instances to achieve the best throughput and low latency rate possible within an Availability Zone. Instances in the cluster placement group may belong to a single VPC or between peered VPCs in the same region.