Intel AS/400 RISC Server, 170 Servers, 7xx Servers manual CPW Application Description

CPW Application Description

The CPW application simulates the database server of an online transaction processing (OLTP) environment. Requests for transactions are received from an outside source and are processed by application service jobs on the database server. It is based, in part, on the business model from benchmarks owned and managed by the Transaction Processing Performance Council. However, there are substantive differences between this workload and public benchmarks that preclude drawing any correlation between them. For more information on public benchmarks from the Transaction Processing Performance Council, refer to their web page at www.tpc.org.

Specific choices were made in creating CPW to try to best represent the relative positioning of iSeries and AS/400 systems. Some of the differences between CPW and public benchmarks are:

yThe code base for public benchmarks is constantly changing to try to obtain the best possible results, while an attempt is made to keep the base for CPW as constant as possible to better represent relative improvements from release to release and system to system.

yPublic benchmarks typically do not require full security, but since IBM customers tend to run on secure systems, Security Level 50 is specified for the CPW workload

yPublic benchmarks are super-tuned to obtain the best possible results for that specific benchmark, whereas for CPW we tend to use more of the system defaults to better represent the way the system is shipped to our customers.

yPublic benchmarks can use different applications for different sized systems and take advantage of all of the resources available on a particular system, while CPW has been designed to run as the same application at all levels with approximately the same disk and memory resources per simulated user on all systems

yPublic benchmarks tend to stress extreme levels of scaling at very high CPU utilizations for very limited applications. To avoid misrepresenting the capacity of larger systems, CPW is measured at approximately 70% CPU utilization.

yPublic benchmarks require extensive, sophisticated driver and middle tier configurations. In order to simplify the environment and add a small computational component into the workload, CPW is driven by a batch driver that is included as a part of the overall workload.

The net result is an application that IBM believes provides an excellent indicator of transaction processing performance capacity when comparing between members of the iSeries and AS/400 families. As indicated above, CPW is not intended to be a guarantee of performance, but can be viewed as a good indicator.

The CPW application simulates the database server of an online transaction processing (OLTP) environment. There are five business functions of varying complexity that are simulated. These transactions are all executed by batch server jobs, although they could easily represent the type of transactions that might be done interactively in a customer environment. Each of the transactions interacts with 3-8 of the 9 database files that are defined for the workload. Database functions and file sizes vary. Functions exercised are single and multiple row retrieval, single and multiple row insert, single row update, single row delete, journal, and commitment control. These operations are executed against files that vary from 100's of rows to 100's of millions of rows. Some files have multiple indexes, some only one. Some accesses are to the actual data and some take advantage of advanced functions such as index-only access.

IBM i 6.1 Performance Capabilities Reference - January/April/October 2008
© Copyright IBM Corp. 2008	Appendix A - CPW and CIW Descriptions	337