Skip to main content

Grids, data centres and reliability

In my work with the Grid Computing Now! Knowledge Transfer Network, I talk about "virtualisation" and "service-oriented architecture" just as much as "grid" itself. People sometimes ask what is the difference between these concepts. My first answer is perhaps rather glib - I say that I don't care as long as the technology gets the job done. Although this is not a straight answer, those of us on the GCN! team believe it is important to put the business answers before any notion of technological purity.

But if we turn to the question as stated, I think that as long as a solution includes the key concepts of virtualised resources and dynamic allocation of applications across those resource, then that to me is enough to call the system a grid. But, of course, we can go further.
A recent conversation reminded me of the important point that distributed systems typically have to manage failure. As systems scale to many machines and many sites, then some of those are going to fail some of the time. The systems have to be resilient enough to adapt and recover. Systems also have to cope with additions and deletions from the set of available resources.

This is most obvious in cycle-stealing grids, which use spare power of desktop PCs, and of scientific grids, which link many research sites across the world. The interesting question is whether this also applies to the data centre. That seems to depend to some extent on how the system is designed. For example, Google is built specifically around this approach; they have always used lots of generic systems and just replaced resources when they fail. I believe Ebay's massive server farms use the same dynamic approach.

This question arose in a conversation I had with Liam Newcombe, an independent consultant. We were supposed to be talking about Green IT (of which more another time), but our discussion wandered to include all sorts of ideas. Liam is working on an open source model of data centre reliability and performance. He believes that reliability is best achieved by adopting this approach of explicitly allowing for it within the software - rather than, for example, attempting to make the hardware itself ultra-reliable.

A key question must be how high up the stack does this awareness have to extend? Can we write applications without worrying about this or does every application have to have some potential adaptability built in? It's a fascinating topic and I look forward to reading the book the Liam is co-authoring, in due course.

Comments

Popular posts from this blog

Webinar: Powering your business with Cloud Computing

On October 14th, I will be hosting a Grid Computing Now! web seminar on the topic of Cloud Computing. We have lined up two very interesting speakers who are using Cloud now to make businesses work. Ross Cooney had a good technological solution to sell but couldn't make it economic until Cloud Computing allowed him to pay for his computation only when he needed it. He will discuss the instant benefits and long term impact of cloud computing to the development, competitiveness and scalability of your application. Alan Williamson created the BlueDragon Java CFML runtime engine that powers MySpace.com. He advises several businesses and will give an overview of the different types of services available and how to avoid being locked-in to a single supplier. You can register for this event here .

Technology Strategy Board: Information Day, 22nd October

I've been asked to publicise the following event. The Technology Strategy Board has arranged an Information Day for Wednesday 22nd October to outline the various R & D Competitions being planned over the next 9 months. This Information Day will provide delegates with an opportunity to find out about the activities of the Technology Strategy Board and gain an understanding of the application process for Collaborative R&D Competitions as well as find out about other Technology Strategy Board activities. The event, being held at the Hyatt Regency Hotel in Central Birmingham, will open at 09:30 for a 10:00 start and will close at approximately 16:30; a full agenda will be available shortly. To register for this event please click on the following link and complete the on-line registration form For more information on the Technology Strategy Board please visit their web site

Business Model Canvas

A Business Model Canvas is a tool for mapping the core functions and capabilities of an organisation.  Compared to the Core Diagrams that I described in an earlier post , the business model canvas attempts to present more aspects of the business, starting with the value proposition – a statement of what the organisation offers to its users (in the business world, to its customers).  It shows the activities and resources, as Core Diagrams do, but also shows user relationships & channels, and also benefits and costs.  I’m not aware of any universities that have used this tool but you can find examples from elsewhere on the web. We are considering business model canvases as a tool for mapping the strategic capabilities of units at the University of Edinburgh.  Phil Taylor, our EA contractor, sketched an outline of what a business model canvas might begin to look like for HR: This is only intended to be suggestive: the real canvas would need to result from in-depth discussions abo