Example Spec - The title of your RFE¶

Use Cases¶

What use cases does this address? What impact on actors does this change have? Ensure you are clear about the actors in each use case: Developer, End User, Deployer etc.

Alternatives¶

What other ways could we do this thing? Why aren’t we using those? This doesn’t have to be a full literature review, but it should demonstrate that thought has been put into why the proposed solution is an appropriate one.

Data model impact¶

REST API impact¶

Security impact¶

Describe any potential security impact on the system. Some of the items to consider include:

Other end user impact¶

Performance Impact¶

Describe any potential performance impact on the system, for example how often will new code be called, and is there a major change to the calling pattern of existing code.

Examples of things to consider here include:

• A periodic task might look like a small addition but if it calls conductor or another service the load is multiplied by the number of nodes in the system.
• Scheduler filters get called once per host for every instance being created, so any latency they introduce is linear with the size of the system.
• A small change in a utility function or a commonly used decorator can have a large impacts on performance.
• Calls which result in a database queries (whether direct or via conductor) can have a profound impact on performance when called in critical sections of the code.
• Will the change include any locking, and if so what considerations are there on holding the lock?

Other deployer impact¶

Discuss things that will affect how you deploy and configure OpenStack that have not already been mentioned, such as:

• What config options are being added? Should they be more generic than proposed (for example a flag that other hypervisor drivers might want to implement as well)? Are the default values ones which will work well in real deployments?
• Is this a change that takes immediate effect after its merged, or is it something that has to be explicitly enabled?
• If this change is a new binary, how would it be deployed?

Assignee(s)¶

Who is leading the writing of the code? Or is this a blueprint where you’re throwing it out there to see who picks it up?

If more than one person is working on the implementation, please designate the primary author and contact.

Primary assignee:

<launchpad-id or None>

Other contributors:

<launchpad-id or None>

Work Items¶

Work items or tasks – break the feature up into the things that need to be done to implement it. Those parts might end up being done by different people, but we’re mostly trying to understand the timeline for implementation.