From: David Lutterkort <[email protected]>
Date: Wed, 02 Mar 2011 16:21:29 -0800
High level question:
Are we trying to resolve
1. Does aeoulous/cloud-engine require that its backends support
stateless images?
2. Is the deltacloud api, itself, stateless?
3. Both 1 and 2.
4. Something else.
My understanding is that the answer to 1 has always been "Yes", and
that it continues to be. I'm agnostic about 2.
To revive this discussion, and put a firm proposal to resolve this
forward, here's what I think the best plan of action is:
Deltacloud
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Need to add the following capabilities to the API:
* Indicate for each image whether it can be used for launching a
stateful or stateless instance [1]
* Make it possible to copy/clone an existing image to a new image
Are these futures? Hugh, is there now discussion of adding stateful
image support to CE for rev1?
If CE doesn't need it, I wouldn't take it as a requirement for DC,
unless there's some unrelated-to-CE reason to think the api needs it.
Aeolus
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Since Aeolus wants to pretend that all clouds only support stateless
images, Condor will start all instances in a two-step process:
1. Ensure a stateless image for the instance exists: if the image
is stateful clone it, otherwise just use the original image
2. Launch the instance of the image from step (1)
3. Delete the cloned image, if necessary, when the instance is
terminated
David
[1] just to keep things clean, we should also indicate whether there is
a restriction on how many instances can be launched off an image
simultaneously (to guard against a freakish cloud that can only launch a
single instance of a stateless image)
