Mainframes ARE IT

by Bob Shimizu

Do you think that mainframe computers aren't cool? Check this out: A lot of the world (and especially the younger folks) think that mainframes no longer exist. They're totally sync'd into technology with PCs, gaming devices, and iEverything. But the fabric of western civilization is held together by mainframe computers. They didn't die and go away. Instead, they retreated into mega datacenters and became MORE POWERFUL.

Deep in bomb-proof basements, huge machines handle millions of transactions a second. They're bigger, faster, more secure and do more than you may be aware of. Do you really think your Visa card is handled by a network of PCs? Nope! Behind all the web-based apps and front-end processing – at the deepest layer – it's all handled by mainframes.

Mainframes ARE IT.

No desktop or laptop PC, no iAnything will ever handle the millions of transactions per second that mainframes do. Nothing approaches the throughput of a mainframe computer, or its inherent security or its reliability.

Throughput: Your PC has eight processors at 3.4Mhz? Yawn. How about 64-processors for each LPAR, with a BUNCH of LPARs on a physical machine? That's what the big banks are running, 24/7. THAT's throughput! "Multi-threading"? Your PC can multi-task? The Wintel memory model is a Frankenstein monster. It was never designed to do what it does today. Mainframe engineers were thinking about – and offering – true multi-tasking twenty years before Windows 3.1. In today's z/OS world, you can define several gigabytes of memory, on the fly, and use it all. It's a very sophisticated virtualization of memory – light years ahead of the Wintel model.

Security: Your Wintel box is constantly in danger of being hacked. You need constant OS updates, a personal firewall and up-to-the-second anti-virus software just to survive the Internet. A mainframe computer has so many layers of security around it – AND built-in protection at the OS level – that you just can't break in. Even if you COULD break in, the architecture is so robust and intricate that you'd lose your way. Forget it: Legions of scary-smart mainframe engineers have been thinking about this problem since before you were born.

Reliability: Somehow, we ACCEPT the fact that a PC or Mac needs to be rebooted periodically because it "loses its way"? In the mainframe world, that engineering would have been scrapped before it EVER hit production! Mainframe computers run for months at a time. You only "reboot" them when you want to – to load new maintenance. And, if things are running along and you need to swap out a processor or increase it's capabilities, you can "hot swap" components without stopping the machine. Do you think that your PC will ever give you 99.999% reliability? Can you swap in a hard drive or upgrade the processor while your PC is running? We don't think so!

Mainframe computing is about SERIOUS engineering on both the hardware and software side. Every possible contingency is evaluated when writing mainframe software. Mainframe software engineers have to guard against corrupted data, improper inputs of all kinds, the possibility of delay anywhere in a process. And a "process" can be many hundreds or thousands of individual programs that run together in an orchestrated flow. Mainframe engineers have to be able to grasp the entire picture and handle interruptions or delays anywhere in the process.

And the operating systems themselves? These are the most complex abstract constructs ever devised by man. No one person can comprehend all that happens inside a modern mainframe OS. You can spend years learning something new every day. They PAY you to learn! Knowledge is power, and that's cool.

Right now, an entire generation of mainframe programmers and technologists are getting ready to retire. This creates opportunity for young people who want to get ahead. Bright young people who want to ensure a great career and a good living should consider getting involved in mainframe technology!