High availability at the low end

Although the Stratus ftServer W Series 2300 doesn’t deliver top-notch performance or provide much room to grow, it’s still worth the extra dough. Running the Standard Edition of Windows Server 2003, this entry-level Intel-based server integrates duplicate sets of system components on a single printed-circuit motherboard, offering high availability at an affordable price.

Other models in Stratus’ line of fault-tolerant servers are configured as 1U “slices” that house redundant components on separate circuit boards. By contrast, this 4U box merges two motherboards into one printed circuit, significantly reducing costs and allowing the ftServer 2300 to compete nicely on price with its nonredundant brethren. Although the circuit board is a potential single point of failure, the ftServer 2300’s low cost and high-availability configuration make it an excellent candidate for locations lacking IT resources, such as remote offices, lights-out environments, and retail or warehouse locations.

Mirror, mirror

The ftServer 2300 consists of two distinct servers working in concert. As with most datacenter systems these days, the 2300 comes with two fans and two power supplies, but it also comes with redundant 3.06GHz Xeon CPUs -- two physical processors comprising one logical CPU -- and two separate sets each of memory and PCI slots. When the system boots up, it queries all these components in stages. If there’s a problem with one, it’s skipped, and the duplicate takes over.

Available but unused working components stand by as active spares until they’re needed. Each set of hardware components runs the same instructions at the same time. If any single component fails, the ftServer will remove the corresponding set of components from service and the second set of components will continue to run without interruption. This Continuous Processing, as Stratus calls it, offers the advantages of high-availability clustering without the need to modify Windows applications or buy additional hardware.

Does it work? Running a custom application designed to shut off various system components, I tried kills of the CPU and disk I/O during testing. In both cases the ftServer didn’t even flinch. Of course, if the server experiences failures in both sets of components simultaneously, a crash will result.

In addition to redundant sets of components, the ftServer 2300 runs hardened device drivers and fail-safe software, which shield the operating system from hardware errors. When -- not if -- an operating system or application failure occurs, the failure is captured and available for later analysis by Stratus personnel. It’s an interesting and efficient way of handling high availability.

Server, phone home

The ftServer 2300 offers everything you expect in hardware and software redundancy. Stratus goes an extra mile in product support, where the options range from ftServer self-service to root-cause analysis of OS and application problems.

The ftServer 2300 constantly monitors its operational status. When it identifies a problem component, it automatically addresses it by securely phoning Stratus headquarters -- via landline or Internet -- and ordering a replacement. The ftServer also has strong remote management capabilities, allowing either in-house IT or Stratus staff to remotely troubleshoot and resolve problems. The out-of-band management module comes in fault-tolerant pairs, of course.