SSD solves bank's traffic jam
Faster I/O processing improves teller service
Texas State Bank switched to solid-state disk when slow transaction processing caused customer service problems.
By M.C. Kincora
As the lines at Texas State Bank's (TSB) drive-through tellers lengthened, it became clear that the bank had more than one kind of traffic jam. During peak check-cashing hours on Friday afternoons, the response time of TSB's transaction processing application was being counted in minutes rather than seconds. Customers and employees alike got hot under the collar waiting for the system to respond.
TSB, founded in McAllen, Texas in 1984, has seen explosive growth in its data volume in the past decade. Besides handling the transactions for its own branches, TSB also processes transactions for seven other independent banks and their branches. Currently, TSB's data center processes about 200,000 check transactions on a daily basis. As the number of transactions processed grew, so did slowdowns in the response times.
Craig Swann, TSB's executive vice president of information systems, could find only two possible explanations for the traffic jams: lack of processor resources or inadequate I/O performance. Swann began exploring processor upgrades for the Unisys NX4800 system that handles transactions. To pinpoint the processor problem, he ran a performance analysis. He was surprised to find that processors were not at fault.
Further analysis showed that TSB's EMC Symmetrix 3000 disk storage system was handling batch processing very well. The bottleneck occurred in online processing, which required greater speed than the drives could provide, explains Swann.
Since I/O performance was the culprit, Blue Bell, Penn.-based Unisys Corp. advised TSB to look into solid-state disk (SSD) technology. I/O performance bottleneck problems can be caused by the inability of mechanical disk drives to spin fast enough to keep up with high-speed processor capabilities in a high volume, high I/O transaction environment such as Texas State Bank's.
Unisys sent TSB an SSD diagnostic software product called Sherlock. Distributed by Englewood, Colo.-based Dynamic Solutions International Corp (DSI), Sherlock is designed to run on Unisys ClearPath NX/A Series mainframes. It traps data about pack file activity, particularly the file size and number of physical I/Os, by trapping file close and file interval records as they are written to the systems SUMLOG file. Sherlock then determines which host files should be moved to an SSD for the maximum performance improvement.
The Sherlock results made it clear that the bank would benefit by installing an SSD system. The DSI, Unisys and TSB team decided that a 3GB Alpine SSD drive system would fit TSB's needs. DSI repackages El Segundo, Calif.- based Imperial Technology Inc.'s SSD drives under its own Alpine brand for the Unisys market. DSI sent Swann an evaluation unit. "We installed it and immediately saw the problems go away," he says.
Being a 24/7 shop, TSB needs its ATM and Internet banking applications to be up all the time. The only window for taking the system down occurs at midnight on weekend nights. "We took the system down at that time and installed the drives via DSI's instructions with the help of on-site Unisys engineers," says Swann. "Within a few hours, the system was back up and functioning."
Swann was pleasantly surprised by how simple and straightforward it was to install the SSD drive. "Usually that's not the case with disk systems," he says.
Swann was impressed by the speed of the solid-state disks. "At the worst, before we used SSD, our response time could be counted in minutes," says Swann. Now, TSB's transaction processing response time averages .2 seconds. "That's outstanding," says Swann.
Although TSB's primary goal with SSD was to improve online response times, the SSD system has improved batch processing performance. Nightly updates used to take six hours to complete. With the Alpine SSD, they only take four hours.
Recently, Swann installed more SSD drives. "We had mirrored all of the disk drives in all of our other disk subsystems, because we are a 24/7 shop and access to data is so critical," says Swann. After deciding that SSD was a keeper, Swann installed backup SSD drives to mirror the transaction drive.
"Mirroring makes it possible to put some larger and more critical files on our initial SSD drive without worrying about losing the information," says Swann. "We hope to put other files on the solid-state system to improve access speed."
This experience has taught Swann the importance of file allocation. His advice to IT managers: "If certain files are very I/O intensive, put those files on the fastest type of disk drive that you can afford."
Swann has been very pleased with the Alpine SSD. "It solved the response time problem. So, our tellers take care of our customers," he says. "It's done everything it was advertised to do."
For more information on Imperial Technology, visit its Web site.
To find out more about Texas State Bank, visit its Web site.
To learn more about Dynamic Solutions International, visit its Web site.
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