IT Management

“TPF has limitations … and the total cost of ownership isn’t low,” says Grigorian. “But TPF is just fantastic, and we won’t compromise the business.”

Part of TPF’s value as a transaction processor for IHG is TPF’s ability to have a database, which it believes is one of the best for rapid transaction processing. IHG also has decades of intellectual investment in its reservation system that makes the system one of the best in the business.

“We think of these benefits because … TPF is an expensive operating system to run,” says Bryson Koehler, vice president of Revenue and Guest Technology at IHG. “The majority of our code is in Assembler, and this can get expensive to maintain. We’re considering moving to z/TPF, but we also know that a migration will be very costly because of the number of regression tests and recompiles it will entail.”

Like other TPF shops, IHG admits it has considered moving off the TPF platform into an alternate environment such as distributed Java. “But we’re a very legacy-oriented shop, and it’s hard to argue with a transaction processor that has proved itself over and over again, and that has been so successful for our business.”


IBM’s release of z/TPF comes at a time when many sites are well under way with initiatives that leverage Linux with z/OS with virtual Linux on the System z. In this environment, the same shops also run pre-production multiple test systems for TPF that are virtualized under z/VM. They have staff already working on other platforms, and already trained in both the z/OS and Linux worlds. With this skills “jump,” they can move right into z/TPF.

The approach works because sites using TPF also are very likely to run z/OS and z/VM.

“TPF does a small number of things very quickly, but there is a limit as to how many tasks can be assigned to a single system instance,” says Boyes. “This is why you are very likely to also find z/OS in a TPF shop, which is used to process any transactional data that doesn’t have a hard real-time processing requirement—and of course, z/VM, which is used to both test and supply many TPF systems to do certain tasks.”

Boyes further clarified that TPF can be run for time-critical tasks outside the z/VM environment by using a Logical Partition (LPAR). In this context, TPF often is a front-end to CICS and talks to a series of time-critical remote processing machines such as those processing credit cards.

“The deployment is done this way because z/VM introduces some overhead,” says Boyes. “There are some systems that simply won’t tolerate this overhead—[such as] credit card processing or air traffic control. … What’s really remarkable about TPF is that when you’re building a TPF application, you’re actually constructing an entire system, with the operating system, application, data management and I/O management all rolled into one. Then, you test the TPF system under z/VM.”

Such benefits may prove enticing to new customers, just as they have to Marriott, IHG, and other veteran users.

”We also are getting new TPF customers in emerging markets where there’s very rapid transaction growth,” says IBM’s Walberg. “As Radio Frequency Identification (RFID) grows globally, with input coming in from remote devices around the world, something also has to be in place to gather all these transaction pieces for processing. TPF has this capability, and it hasn’t gone unnoticed.”

TPF may not remain obscure indefinitely as that “other” operating system; because of timely enhancements in z/TPF, it may even flourish.  

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