What are Service Units?

This is a new feature of the Nectar cloud, for existing users please also see what has changed

A Service Unit (SU) is a measure of the cost of using Nectar compute resources. Each Nectar flavor has an associated SU-per-hour cost, as set out in the Nectar Flavors document.

Methodology: There is an (internal) formula that is used to convert the flavor attributes (VCPUs, CPU priorities, RAM and so on) to a base SU cost per hour for each flavor.  The base cost is then adjusted for various reasons.  For example, the costs of the deprecated (m1, m2, etc)  flavors are weighted to encourage users to migrate to newer flavors.

Currently, we only assign an SU cost to explicit computational resources. In the future, we may extend this model to resources such as load balancers and databases that have associated implicit compute resources.

Note: When instances are shut down or suspended, they still continue consuming SU's. Only when an instance is shelved or deleted, then it will stop consuming SU's.

Requesting a Service Unit Budget

Each allocation will have a Service Unit Budget.  This is the number of Service Units that can be used by the project in its current allocation period; i.e. from the start date to the end date. Your allocation’s Service Unit Budget is requested on the Allocation Request form, and is subject to review and approval by the allocation approvers.

As you fill in the Allocation Request form, you will need to estimate how many SUs you require.

Notes about the Service Unit Budget :

  1. Unused Service Units do not “carry over” to the next allocation period.

  2. If you consume 100% of your Service Unit Budget before the end of the allocation period, the project expiration process starts, just as if you had reached the end of your allocation period. 

  3. If your project’s budget will be consumed before the end of the project allocation period, you can submit an “early” request to renew. The Approvers will make a judgment as to whether or not to grant your request based on the circumstances, and on resource demand from other Nectar projects.

More information

How to estimate a Service Unit Budget

Understand how to track your Service Unit usage

Transitioning current allocations to a Service Unit Budget