1장. Understanding DCN

Distributed compute node (DCN) architecture is for edge use cases that require Compute and storage nodes to be deployed remotely while sharing a centralized control plane. With DCN architecture, you can position workloads strategically closer to your operational needs for higher performance.

The central location consists of, at a minimum, the RHOSO control plane installed on a Red Hat OpenShift Container Platform (RHOCP) cluster. Compute nodes can also be deployed at the central location. The edge locations consist of Compute and optional storage nodes.

DCN architecture consists of multiple availability zones (AZs) to ensure isolation per-site scheduling of the OpenStack resources.

You configure each site with a unique AZ. In this guide, the central site uses az0, the first edge location uses az1, and so on. You can use any naming convention to ensure that the AZ names are unique per site.

그림 1.1. Basic distributed compute node architecture with storage

DCN architecture is a hub-and-spoke routed network deployment. DCN is comparable to a spine-leaf deployment for routed provisioning and control plane networking with RHOSO.

When you launch an instance at an edge site, the required image is copied to the local Image service (glance) store automatically. You can copy images from the central Image store to edge sites by using glance multistore to save time during instance launch.