Читать книгу AWS Certified Solutions Architect Study Guide - Ben Piper, David Higby Clinton - Страница 57

By default AWS will attempt to spread your instances across their infrastructure to create a profile that will be optimal for most use cases. But the specific demands of your operation might require a different setup. EC2 placement groups give you the power to define nonstandard profiles to better meet your needs. There are, at this time, three kinds of placement groups:

 Cluster groups launch each associated instance into a single availability zone within close physical proximity to each other. This provides low‐latency network interconnectivity and can be useful for high‐performance computing (HPC) applications, for instance.

 Spread groups separate instances physically across distinct hardware racks and even availability zones to reduce the risk of failure‐related data or service loss. Such a setup can be valuable when you're running hosts that can't tolerate multiple concurrent failures. If you're familiar with VMware's Distributed Resource Scheduler (DRS), this is similar to that.

 Partition groups let you associate some instances with each other, placing them in a single “partition.” But the instances within that single partition can be kept physically separated from instances within other partitions. This differs from spread groups where no two instances will ever share physical hardware.