DB2 for z/OS Buffer Pool Simulation

By Jeff BergerDB2 z/os buffer pool computer memory

For many years the price of z/OS memory has been decreasing, and IBM has been pushing the idea of large amounts of memory. DB2® for z/OS has virtually eliminated its virtual storage constraints.

DB2 performs best when it has lots of memory (i.e. real memory). Memory is still not free, but large memory can save money by reducing CPU consumption while at the same time reducing DB2 transaction response time. More memory also increases DB2 availability in cases where it is necessary to dump the DB2 address space, because if dumping causes paging to occur, the dump will take longer, and DB2 is not available during that time.

DB2 Buffer Pool Analyzer for z/OS

The first thing that comes to mind for the use of large memory is to increase the size of DB2 buffer pools. This can reduce the number of synchronous I/Os by increasing the buffer hit ratio. Furthermore, reducing the number of synchronous I/Os will reduce CPU consumption, because I/Os cost CPU time.

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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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Game Changer for z/OS Transaction Reporting

Todd-Havekost

By Todd Havekost

Periodically, a change comes to an industry that introduces a completely new and improved way to accomplish an existing task that had previously been difficult, if not daunting. Netflix transformed the home movie viewing industry by offering video streaming that was convenient, affordable, and technically feasible – a change so far-reaching that it ultimately led to the closing of thousands of Blockbuster stores. We feel that IBM recently introduced a similar “game changer” for transaction reporting for CICS, IMS and DB2.

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