Diagramming Clouds

Welcome to one of the pleasures (!) of early days in a new technology area.  We spend a lot of time arguing about (or you could say discussing) just what we're talking about, where the edges are, and what to call things.  I'm famous for sitting in these discussions with a yellow pad rather than my computer because I want to sketch diagrams and charts and they are hard to do with today's interfaces and tools (and, yes, I have tried some of the drawing, charting, and mind-mapping tools).

What follows was initially sketched on the back of an envelope during lunch with a colleague, Michael Salsburg.  He's Chief Architect at Unisys.  We have lunch every month to talk about what's going on (in the industry -- no secrets are exchanged).  We're both quite interested in cloud computing and we've been trying to decide what a cloud computing architecture looks like.

NOTE:  He's a formal architect; I'm not.

I noted that I was using this layer cake approach:

Integration of Applications

SaaS Software

Management

Utility Computing  (Infrastructure)

I discussed the fact that you could know buy infrastructure from a platform vendor (Amazon, Google, Opsource, IBM, etc.) with or without the Management layer.  ISVs (or customers, for that matter) could then add SaaS applications.  Few have gotten to the top layer where they try to enhance the user experience by integrating the applications (which may be coming from multiple platforms and applications), offering them under a single sign-on and interface (hard), and offering at least some data integration.

Michael Salsburg noted that he was thinking about a different architecture:

Management	XAAS
	Utility Computing

In his version, Management isn't a separate layer, but rather a layer that sits outside everything else and integrates and manages it.  I liked that a lot.  In fact, I ended up altering my own chart as a result:

Management	Integration of Applications
	SaaS Software
	<------------------------------------------Management
	Utility Computing  (Infrastructure)

The layer cake has changed, with Management moving out to the left, becoming a separate element that integrates all the other layers.  Now I'll be testing offerings to see how well they can fit this newer and more sophisticated architecture.

The cloud is in a constant state of flux.  Improvements, both intellectual and physical are welcome.  So are your comments.