[Planetlab-devel] NM semantics

[Justin Cappos]

On Dec 5, 2007 6:46 PM, Faiyaz Ahmed <faiyaza at cs.princeton.edu> wrote:

> Hi Stephen,
>
> I can remove the Create() from the Ticket() call. It really is unneeded
> to have both encapsulated in 1 call and the ability to have a slice
> ready but not started may appeal to some users.
>

What does 'ready' mean?   The reason why I requested this is that sometimes
I'm going to want to destroy a VM that may not exist (I can't be sure) and I
need to pass the ticket before calling destroy.





>
>  >Why is NM keeping a record of data that is returned by the next
> GetSlivers?? call anyway?
>
> NM cache's getslivers data if connectivity to PLC is lost and operations
> on slivers needs to continue (ie. expiration, bandwidth limiting, etc).
> When connectivity exists, GetSlivers?() is called periodically by NM to
> the PLC API, and the NM database (cache) is updated with the latest
> slice information.
>
> During the time between polls, a user may dynamically create or destroy
> a sliver. For this operation to complete, the same information presented
> by GetSlivers? needs to be present in NM's database, so a natural work
> around is to encapsulate the sliver information in the signed ticket
> itself. The next time NM calls GetSlivers?, and attributes for the
> sliver have changed, the updated attributes are used in place of
> attributes presented by the ticket.
>

Also, I'm not sure I understand what you're saying here, but VMs are not
destroyed automatically if I neglect to add them to PLC.   They happily
exist on the node until I tell the NM to destroy them without me ever
contacting PLC.

Thanks,
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.planet-lab.org/pipermail/devel/attachments/20071205/221801c4/attachment.html