Paul Strong of Sun has a very good article in the most recent of ACMQueue. His subject (and the subject of the entire issue) is enterprise grid.
He makes some great points. He starts by looking at the enterprise data center.
Today’s data center could be viewed as a primordial enterprise grid. The resources form a networked fabric and the applications are disaggregated and distributed. Thus, the innate performance, scaling, resilience, and availability attributes of a grid are in some sense realized. The economies of scale, latent efficiency, and agility remain untapped, however, because of management silos. How can this be changed? And what is the difference between an enterprise grid and a traditional data center?
This is exactly right. The data center has great potential for grid-enablement. He points to Microsoft's Dynamic Systems Initiative and Sun's N1 Software as examples of how the data center is evolving. But Microsoft is quick to point out that DSI is an initiative, not a product:
The Dynamic Systems Initiative (DSI) is a commitment from Microsoft and its partners to help IT teams capture and use knowledge to design more manageable systems and automate ongoing operations, reducing costs and freeing up their time so they can proactively focus on what is truly important.
Similarly, N1 is software that helps run a datacenter.
What neither of them do is dynamically take advantage of the compute resources in a datacenter to ensure that the tasks that need compute power are receiving it, and that would-be idle machines are lending compute power when they can.
Paul's article spends a lot of time talking about why people might want a grid, then extols the benefits of virtualization, seamless use of heterogeneous resources, "holistic architecture," and abstraction. These are all long term benefits that people are looking forward to; organizations like the Enterprise Grid Alliance and the Global Grid Forum are creating standards to ensure that these goals become reality.
However, those goals are fairly abstract and, for most organizations, not the place to start experimenting with grid computing. Above all, the promise of grid is what Paul Strong notes in the first page of his article:
You can apply far more resources to a particular workload across a network than you ever could within a single, traditional computer. This may result in greater throughput for a transactional application or perhaps a shorter completion time for a computationally intensive workload.
Oddly enough, this is in the section of the article entitled "Hype." Strange, because this is the promise of grid that can actually be realized today. Grid computing is about making things go faster, and people are doing this now. It isn't hype. It's been happening for a few years with a few different Linux and UNIX solutions; it's happening now with Windows solutions (because of solutions like Digipede.
I look forward to the hype of grid computing--millions of PCs available just by plugging a computer in the wall, massive virtualization, seamless repurposing of millions of heterogeneous machines. But I also like where grid is now: tapping dozens, hundreds, or thousands of machines in the enterprise, making slow things happen faster.