“cover what I had neglected previously: performance considerations. Here, I will focus solely on the compute part of OpenStack”
Making the most of your application performance on OpenStack Cloud
by Piotr Siwczak

• Get to know your potential workload
• Choose the right proportions for OpenStack compute resources
• Choosing the right hypervisor for OpenStack
• Hypervisor and guest optimizations
• Choosing the right compute node
• Choosing the right user data storage
• Networking Capacity in OpenStack
• Avoid “enterpriseness” and shared resources

 

It turns out that in OpenStack, “controller node” and “compute node” can have variable meanings given how flexibly OpenStack components are deployed
Understanding your options: Deployment topologies for High Availability (HA) with OpenStack
by Piotr Siwczak

 

• Endpoint node: This node runs load balancing and high availability services that may include load-balancing software and clustering applications. A dedicated load-balancing network appliance can serve as an endpoint node. A cluster should have at least two endpoint nodes configured for redundancy.
• Controller node: This node hosts communication services that support operation of the whole cloud, including the queue server, state database, Horizon dashboard, and possibly a monitoring system. This node can optionally host the nova-scheduler service and API servers load balanced by the endpoint node. At least two controller nodes must exist in a cluster to provide redundancy. The controller node and endpoint node can be combined in a single physical server, but it will require changes in configuration of the nova services to move them from ports utilized by the load balancer.
• Compute node: This node hosts a hypervisor and virtual instances, and provides compute resources to them. The compute node can also serve as the network controller for instances it hosts, if a multihost network scheme is in use. It can also host non-demanding internal OpenStack services, like scheduler, glance-api, etc.
• Volume node: This is used if you want to use the nova-volume service. This node hosts thenova-volume service and also serves as an iSCSI target.

 

 

 

• Rackspace Open Cloud Reference Architecture
• OpenStack Documentation / Compute Administration Manual: Example Installation Architectures
• Ken Pepple: OpenStack Nova Architecture
• OpenStack Wiki: Real Deployments
• OpenStack Documentation: Compute and Image System Requirements
• OpenStack Documentation / Compute Administration Manual: Service Architecture