Credit Card Transaction Timeouts – IOSQ Analysis

By Joe HydeCredit Card Transactions - IOSQ Analysis

Black Friday is one of the busiest transaction days of the year, and it often seems like an easy payday for most participating companies. But have you ever wondered what performance preparations must be made to accommodate the overly inflated volume of credit card transactions?

A large global bank was struggling because their latest version of a credit card swipe application was failing at high volume load testing. In preparations for Black Friday they needed the application to handle a much higher number of credit card swipes, but periodically their credit card transactions were timing out.

When we became involved they had spent weeks on the issue, thousands of man-hours and had incurred significant financial penalties because of the delays. They had spent the past two weeks on day-long conference calls with over 100 people on the phone (often forcing some off the line so others could join) all pointing fingers at one another. The performance team, application team, storage team, and the vendor all blamed one another for the timeouts.

You see, the delays had a significant revenue impact to their business as any credit card approval that timed out had to be sent over a competitor’s exchange, incurring significant fees. After the two weeks of conference calls proved to be unsuccessful in determining the root cause of the problem, they called us in. We took a deep dive into some of the key storage metrics and were able to provide the key insight in determining root cause of the timeouts in a few days of research and additional data acquisition.

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IBM z/OS’s Microscope – GTF

By Joe Hyde

chemistry icons background

Remember the first time you looked at pond water under a microscope? Who knew such creatures even existed, let alone in a drop of water that appears clear to the naked eye.

IBM z/OS also provides a microscope. It’s called the Generalized Trace Facility, GTF for short. With a GTF I/O summary trace you can look deeply into the inner world of your storage systems. What appears innocuous at the RMF level can have some surprising characteristics when put under the GTF microscope. However, GTF contains so much data that it is not easy to “focus” this microscope and get out all the information. Fortunately, IntelliMagic now created software to process and analyze GTF I/O summary traces, such you can focus on the gems that are hidden in GTF I/O traces using IntelliMagic Vision.

To illustrate the value of analyzing GTF data, here is a story on how I used this feature to show something otherwise invisible. I recently blogged about DB2 work volumes that were exhibiting high device busy delay times. A DS8870 firmware upgrade eliminated this problem, but only when I analyzed the GTF I/O summary trace using the new feature could I really explain why the firmware upgrade made such a marked improvement. Continue reading