The Rise of Grid
Grid computing takes advantage of networked computers, creating a virtual environment that distributes application processing across a parallel infrastructure. Grids can employ a number of computational models to achieve their goal of high throughput.
Heterogeneous grid computing relies on a mix of different, geographically distributed computers to solve massive computational problems such as simulating earthquakes. Mainframes in California and Massachusetts may work with clusters of midrange systems in China and thousands of PCs across Europe to solve a single problem.
The drive to heterogeneous grid computing arose from sheer frustration. With limited access to scarce, expensive resources such as supercomputers, users recognized that compute-intensive problems could be broken up and distributed across multiple, lower cost machines that were readily available. Typically, the resulting calculations could be delivered faster and more cost effectively.
With the advantages of grid computing, the appearance of homogeneous grids simply reflects the fact that clusters of low-cost, homogenous PCs running Linux can be a genuine alternative to higher priced computer architectures. Numerous Wall Street firms now run complex financial simulations such as Monte Carlo calculations on large clusters of Linux machines.
On the Web, the massive throughput offered by grid computing takes on a new meaning. Rather than focus on solving a single problem—sequencing the human genome, for example—a grid can focus on executing a single task, such as serving web pages. Web portals such as Google, Yahoo, and Amazon all have demonstrated the efficacy of running thousands of commodity Linux machines as web servers.
Clearly, the grid architecture works for many well-known Internet companies. Now, users are starting to move transactional applications onto the grid architecture. The all-or-nothing nature of transactional applications can make moving to commodity grid computing a delicate matter for companies that are used to running these applications on high-end architectures that are perceived as more robust and reliable. On the other hand, the grid advantages can prove to be an irresistible lure.
