If you use PayPal, you're tapping into a 4,000-server Red Hat Enterprise Linux grid
PayPal processes $1,571 worth of transactions per second in 17 different currencies on about 4,000 servers running a specially stripped-down and security-enhanced version of Red Hat Enterprise Linux, according to Information Week.
(PayPal Chief Technology Officer Scott) Thompson supervises a payment system that operates on about 4,000 servers running Red Hat Linux in the same manner that eBay and Google conduct their business on top of a grid of Linux servers. "I have been pleasantly surprised at how much we've been able to do with this approach. It operates like a mainframe," he said.As PayPal grows it's much easier to grow the grid with Intel-based servers than it would be to upgrade a mainframe, he said. In a mainframe environment, the cost to increase capacity a planned 15% or 20% "is enormous. It could be in the tens of millions to do a step increase. In [PayPal's] world, we add hundreds of servers in the course of a couple of nights and the cost is in the thousands, not millions," he said.