Before we go down the path of creating twice as much work for half the gain
let me challenge a core assumption here: contrary to what is being assumed,
the PaaS model will not work for education unless structured within an IaaS
framework! This is not because of elegant technical considerations but
rather the most basic and practical of considerations--within the
educational domain the "achievable" economics of the two models are
significantly different with the decisive advantage going to the IaaS model!
The proof is somewhat tedious but I will work it up. 

In the meantime, could we do this in a way that minimizes the reverse
engineering necessary to port the key functionality of what you are
purposing to do back into a more viable economic framework? I will concede
up front and without debate that what you are proposing is a better solution
for certain service provider scenarios. But with that said, it is NOT a
better solution for the grossly underserved educational community where cost
is a tradeoff between free lunch and technology facilitated learning
opportunities. The harsh reality is that cost is the single most, and
sometimes the only, relevant criteria in making educational decisions.
Absent affordability it doesn't much matter what the solution looks like
because the underserved will not be using it.

If we want a different outcome, this is where it has to begin.

Sam Averitt 

-----Original Message-----
From: John Bass [] 
Sent: Thursday, May 14, 2009 4:16 PM
Subject: Re: VCL Experimental Architecture

I agree. Here is a starter list of high level issues:

- architecture modularity
 . core
 . resource management
 . gui/api
 . operational metrics and logging
 . component templating
- security model
- database independence/abstraction
- language independence
- storage implementation (user and image)
- virtualization management
- future extensibility
- experimental development branch

I'm working on a summary of security model issues. The idea behind the vcl
security model is to list and encapsulate  each of the components, objects,
roles, etc in the architecture so that most any security model can be
implemented instead of locking the project into a particular security model
(although we'll have to start with one model). Currently, the security model
is undefined and 'hard-wired' into the architecture. This greatly limits the
ability for vcl to be deployed into new environments with different security
policies or to adapt to future security policies in currently deployed
environments. More on this later.

Please feel free to jump in on a topic. There is lots to discuss.

John Bass
(919) 515-0154

On Thu, May 14, 2009 at 3:40 PM, Josh Thompson

> Hash: SHA1
> I really think that before any more implementation design work is done
> toward
> long term restructuring, a lot of high level discussion and design work
> needs
> to be done.  It causes a fractured community if a few people in the
> community
> decide to redesign large parts of the codebase without having discussions
> about it on this list.
> Josh
> On Thursday May 14, 2009, Andrew Brown wrote:
> > I've just made a clarification on the vcl experimental architecture
> > document:
> >
> > In regards to the core's frontend API interface about values including
> > image_id, ticket_id, and so fourth, the frontend needs to map which
> > resource manager corresponds to those values, but they may or may not be
> > unique. To solve this, it needs to be paired with its resource manager
> id.
> > Here's how that will work:
> >
> > "Above" the core, i.e. in communication with a frontend, values such as
> > image_id and ticket_id will be a tuple: (resource_manager_id, actual_id)
> >
> > "Below" the core, i.e. in communication with a resource manager, these
> > values will be just a single integer.
> >
> > This way the core won't need to keep some kind of mapping (which
> > work anyways since the ids are only unique to a single resource manager)
> > nor will it need to poll all resource managers for the right one. The
> > frontend will be responsible for passing both values back to the core.
> > -Andrew
> - --
> - -------------------------------
> Josh Thompson
> Systems Programmer
> Virtual Computing Lab (VCL)
> North Carolina State University
> 919-515-5323
> my GPG/PGP key can be found at
> Version: GnuPG v1.4.6 (GNU/Linux)
> Q/0EoJ3rssbEgdUAEjc6yIQ=
> =5H1g

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