Hi,
I wrote up current status of instance states, and described a proposal how we could implement this feature.
Rather than paste in the entire text, I'm just linking to the wiki writeup. https://www.aeolusproject.org/redmine/projects/aeolus/wiki/Design_the_model_...
Any thoughts or improvement ideas are welcomed.
-- Jozef
On 04/18/2012 03:57 PM, Jozef Zigmund wrote:
Hi,
I wrote up current status of instance states, and described a proposal how we could implement this feature.
Rather than paste in the entire text, I'm just linking to the wiki writeup. https://www.aeolusproject.org/redmine/projects/aeolus/wiki/Design_the_model_...
Any thoughts or improvement ideas are welcomed.
-- Jozef
Hi Jozef, I might be completely wrong but from the subject: "Design the model changes for support of stateful instances" I think that the goal is slightly different than what you describe on the wiki page. The thing is that now, when a user stops an instance, there is no way how to start the instance again later because till now we considered all instances to be stateless (not re-launchable).
Off the top of my head, to add stateful instances we will have to: - distinguish between stopped (re-launchable) and terminated state - update method which compute uptimes - update deployment/instance launch methods to be able to work with existing objects (now we always create new instance/deployment) - allow start action for stopped instances (and probably for whole deployments?) in UI
Jan
On 04/20/2012 07:59 AM, Jan Provazník wrote:
On 04/18/2012 03:57 PM, Jozef Zigmund wrote:
Hi,
I wrote up current status of instance states, and described a proposal how we could implement this feature.
Rather than paste in the entire text, I'm just linking to the wiki writeup. https://www.aeolusproject.org/redmine/projects/aeolus/wiki/Design_the_model_...
Any thoughts or improvement ideas are welcomed.
-- Jozef
Hi Jozef, I might be completely wrong but from the subject: "Design the model changes for support of stateful instances" I think that the goal is slightly different than what you describe on the wiki page. The thing is that now, when a user stops an instance, there is no way how to start the instance again later because till now we considered all instances to be stateless (not re-launchable).
Off the top of my head, to add stateful instances we will have to:
- distinguish between stopped (re-launchable) and terminated state
The real "fun" here is that a lot of this is provider-specific. Generally, the hope will be that something in the 'stopped' state can be started again, but that a 'terminated' instance can not start again. This may not be true for all providers, though. Deltacloud has a notion in the driver of the valid state transitions for an instance, so we can use that to determine whether a 'stopped' instance may be restarted. The other thing we'll need to decide is whether we'll continue to fully support stateless instances alongside stateful instances, or are we moving to stateful-only? In the former case, will the stateful/stateless decision be made in the image, the instance, the deployable, or the deployment? Is there a need to support deployments with both stateful and stateless components?
- update method which compute uptimes
Uptime and run history. Really, we probably need to know each time an instance was started and stopped, as well as maintaining an accumulated uptime measurement.
- update deployment/instance launch methods to be able to work with
existing objects (now we always create new instance/deployment)
So I would imagine that the "launch" sequence we have now will be mostly unchanged (except for, possibly, needing a stateful/stateless tab). Launch == "Create and Start", and the whole UI is based on choosing a set of images to create a new deployment. For starting a previously-run instance/deployable, we wouldn't need the launch sequence -- the user would see a 'start' action on the deployment details page, and there might be a 'start' action on the list view alongside the 'stop' action to allow restarting of more than one deployment at a time.
- allow start action for stopped instances (and probably for whole
deployments?) in UI
Yeah, I'd think that the deployment level would be the main focus here -- 'stop deployment', then 'start deployment', etc. As it is we're limiting actions on individual instances within a deployment. If we allow individually stopping instances in a deployment, then restarting should also be allowed.
Jan
Scott
On Wednesday 18 April 2012 15:57:32 Jozef Zigmund wrote:
Hi,
I wrote up current status of instance states, and described a proposal how we could implement this feature.
Rather than paste in the entire text, I'm just linking to the wiki writeup. https://www.aeolusproject.org/redmine/projects/aeolus/wiki/Design_the_model_ changes_for_support_of_stateful_instances
Any thoughts or improvement ideas are welcomed.
-- Jozef
Hi,
I've updated the wiki page https://www.aeolusproject.org/redmine/projects/aeolus/wiki/Design_the_model_...
After gathering more information, I've proposed (with Jan's help) those tasks to establish stateful instances in Conductor.
Again any thoughts or improvement ideas are welcomed
-- Jozef
aeolus-devel@lists.fedorahosted.org