[Engine-devel] Adding atomic restore snapshot command at backend

[Livnat Peer]

On 28/05/12 12:59, Michael Pasternak wrote:
> 
> Currently 'restore snapshot' done in two steps on a client side:
> 
> 1. TryBackToAllSnapshotsOfVm
> 2. RestoreAllSnapshots
> 
> This implementation creates race condition on 1 and therefore unstable & bug prone,
> i suggested refactoring 2 to include 1 as single atomic operation at backend.
> 
> 

Hi Michael,

The two commands above are used for functionality that is needed
regardless of the functionality you are looking for.
We want to present the user the option to preview a snapshot without
committing to it and without loosing the current snapshot.
I think we need to model the the two options above in the REST, it is
functionality that is used in the UI.

What you are looking for is a functionality 'restore to snapshot', this
functionality does not exist in the engine in a single step, and I think
that because we assumed that the user can get it in two steps It wasn't
prioritize so far.

Implementing the missing functionality with the two functions above is
a compromise that was done in the API.

To summarize I think the requirement you present is a missing
functionality in the engine and solving it is not about refactoring the
two existing verbs into one.

Thanks, Livnat