fuel-docs/pages/reference-architecture/0030-cluster-sizing.rst

Cluster Sizing

Cluster Sizing

This reference architecture is well suited for production-grade OpenStack deployments on a medium and large scale when you can afford allocating several servers for your OpenStack controller nodes in order to build a fully redundant and highly available environment.

The absolute minimum requirement for a highly-available OpenStack deployment is to allocate 4 nodes:

• 3 controller nodes, combined with storage
• 1 compute node

If you want to run storage separately from the controllers, you can do that as well by raising the bar to 9 nodes:

• 3 Controller nodes
• 3 Storage nodes
• 2 Swift Proxy nodes
• 1 Compute node

Of course, you are free to choose how to deploy OpenStack based on the amount of available hardware and on your goals (such as whether you want a compute-oriented or storage-oriented environment).

For a typical OpenStack compute deployment, you can use this table as high-level guidance to determine the number of controllers, compute, and storage nodes you should have:

# of Nodes	Controllers	Computes	Storages
4-10	3	1-7	3 (on controllers)
11-40	3	3-32	3+ (swift) + 2 (proxy)
41-100	4	29-88	6+ (swift) + 2 (proxy)
>100	5	>84	9+ (swift) + 2 (proxy)