TOURCast Behind the Scenes
TOURCast's back end is a variable set of Linux servers run from IBM's on-demand hosting center, on IBM zSeries machines. The choice of Linux was actually a simple one for PGA TOUR, because PGATOUR.com itself had been running on Linux servers since 2000 at the recommendation of IBM. PGATOUR.com had proved incredibly solid with excellent uptime, so the group saw no reason to move away from their choice of server operating system.
IBM's on-demand hosting was also an easy sell, as this is entirely a Linux-based service and provides the flexibility needed by an application with fluctuating CPU and bandwidth needs. This service consists of a collection of firewalls, switches, load balancers, and zSeries machines. zSeries boxes are 64-bit servers with one to four CPUs on board. Where mainstream PC multi-CPU machines are not fully utilized unless an application is specifically written to take advantage of multiple processors, a zSeries machine separates the work among its processors in the hardware layer, meaning that any program can take advantage of the multiprocessing capabilities (the application must be written for a 64-bit rather than a 32-bit architecture).
TOURCast is stored as a server image in the on-demand control center, storing all its data on shared storage servers. It has its own custom security boundaries, and PGA TOUR initially designated what it thought would be the CPU and network load required. For the first three months of service, IBM tracked all aspects of bandwidth usage, CPU usage, and more, working with PGA TOUR to design the most appropriate service package for their needs, much like a cell phone carrier might. Monitoring continues; if usage for the one to four CPUs in the TOURCast server starts to climb, a new CPU can be added, or the TOURCast image can be pushed out to a new zSeries server at a moment's notice, and another one to four CPUs can be engaged.
With bandwidth, it's simpler. Just as PGA TOUR can contract for half of a CPU or more per month, they also contract for a specified average bandwidth per month. When TOURCast needs more "zoom" than contracted, that amount comes automatically, at a premium charge for the additional time, storage space, or bandwidth usage.
And the usage does spike. Typically, the hardest hits come from when play doesn't end on Sunday night, but is held over until Monday. By this point, most people are back at work and don't have television or radio access. Instead, subscribers rely on TOURCast for all of their golf news. (On a standard hosting setup, this situation would either slow the existing servers, or require new servers to be brought in at the last minute.)
For Evans, this scalable solution what would doubtless would be years lost from his life due to stress. "On Sunday night at 6:00 p.m.," he points out, "there's not much planning you can do for the next day. You can't just roll a pile of servers in for Monday morning." With on-demand bandwidth and CPUs are already there, waiting for the challenge.