[Ovirt-devel] Thoughts about taskomatic redesign

[David Lutterkort]

On Mon, 2008-06-23 at 11:06 +0200, Chris Lalancette wrote:
> 3)  Transaction support in taskomatic (hi slinaberry!).  I'm not sure about this
> one; we are modifying state external to the database, so I'm not sure
> "rolling-back" a transaction means a whole hill of beans to us.  In fact, I
> might argue that rolling back is worse in this case; if you modified external
> state, and then crashed, when you come back you might "roll-back" your VM state
> to something that's totally invalid, and you'll need to be corrected by
> host-status anyway.  Does anyone have further thoughts here?

I wouldn't even worry about rolling back transactions - it seems like a
lot of pain for very dubious gain.

A slightly related question is: how do you deal with user actions that
require multiple tasks to be performed ? You'd need to keep track of
some higherlevel object that groups related tasks together, and when one
of them fails give the user an option to retry (e.g. when creating a
StoragePool failed, user adds manually more storage and then restarts
that whole task group, which will only redo the tasks that failed or
blocked on failure)

David