Haizea

Haizea currently assumes that non-preemptable leases (such as, in practice, many immediate and AR leases) will run in full, and that the user would not want it to be suspended or resumed. As such, Haizea does not provide an API for users to request that the lease be temporarily suspended. However, user-requested suspension is a realistic scenario: a user may be using a VM interactively, knows he won't use it for a period of time (e.g., overnight), but still wants to have those resources available when he returns. Currently, Haizea would only allow this to be done by requesting separate leases for each interval of time during which the VM is going to be used (however, whether the VM image will persist correctly has not been tested with OpenNebula).

Adding this functionality has implications over several components:

• Lease data structure: Should be able to express this availability scenario (where a user may want a lease to be suspended)
• Scheduling: Supporting this would require modifying some of the scheduling algorithms, since Haizea can't predict when a user will want his resources back.
• XML-RPC API: The user must have a way to request that the lease be suspended/resumed.

I'm opening this ticket to discuss how we would go about implementing this functionality.