Rational Team Concert For z/OS Incremental Build Performance Comparison Between Releases

Introduction

The performance data provided is obtained by benchmark test of each release. The report includes build duration and links to the detailed build activities.

Disclaimer

The information in this document is distributed AS IS. The use of this information or the implementation of any of these techniques is a customer responsibility and depends on the customer’s ability to evaluate and integrate them into the customer’s operational environment. While each item may have been reviewed by IBM for accuracy in a specific situation, there is no guarantee that the same or similar results will be obtained elsewhere. Customers attempting to adapt these techniques to their own environments do so at their own risk. Any pointers in this publication to external Web sites are provided for convenience only and do not in any manner serve as an endorsement of these Web sites. Any performance data contained in this document was determined in a controlled environment, and therefore, the results that may be obtained in other operating environments may vary significantly. Users of this document should verify the applicable data for their specific environment.

Performance is based on measurements and projections using standard IBM benchmarks in a controlled environment. The actual throughput or performance that any user will experience will vary depending upon many factors, including considerations such as the amount of multi-programming in the user’s job stream, the I/O configuration, the storage configuration, and the workload processed. Therefore, no assurance can be given that an individual user will achieve results similar to those stated here.

This testing was done as a way to compare and characterize the differences in performance between different versions of the product. The results shown here should thus be looked at as a comparison of the contrasting performance between different versions, and not as an absolute benchmark of performance.

What our tests measure

We use predominantly automated tooling such as Rational Performance Tester (RPT) to simulate a workload normally generated by client software such as the Eclipse client or web browsers. All response times listed are those measured by our automated tooling and not a client.

The diagram below describes at a very high level which aspects of the entire end-to-end experience (human end-user to server and back again) that our performance tests simulate. The tests described in this article simulate a segment of the end-to-end transaction as indicated in the middle of the diagram. Performance tests are server-side and capture response times for this segment of the transaction.

Findings

Based on the test data, incremental build performance of the RTC for z/OS has improved significantly from 4.0.2 to 6.0.1.

• From 4.0.2 to 5.0.2, the overall improvement of the build time is about 30% to 50% depending on different test scenarios.
• From 5.0.2 to 6.0, the time of incremental build with large change set improved more than 20%. "Collecting buildable files" and "Updating dependency data" activities during build preprocessing are the main improved activities.
• From 6.0 to 6.0.1, "Updating Dependency data" activity is improved 120% and 'Compile' activity is improved 6%.

Constant performance enhancements have been made into release 4.0.3, 4.0.5, 4.0.6, 5.0, 6.0 and 6.0.1 to improve the build preprocessing speed.

Topology

The tests are executed in a Single Tier Topology infrastructure like the one in the following diagram:

Single Tier Topology: zLinux

The RTC server was set up based on WebSphere and DB2 on Linux for System z. The build machine with Rational Build Agent was on zOS.

Methodology

The sample projects for the test are:

• Mortgage Application *100 which is 100 duplicates of the Mortgage sample application
• Mortgage Application *1000 which is 1000 duplicates of the Mortgage sample application

In the repository the source code is stored in one stream with one single component which includes 5 zComponent Projects.

Enterprise builds are executed twice against each version.

Test Scenario Description

After a complete build of all the programs, different changes are performed and a rebuild requested. These requests will rebuild the changed programs and impacted ones.

Results

Run duration & Build Activities

The charts below show the run duration comparison from 4.0.2 until 6.0.1. Builds are run twice against each release and the average time is taken for comparison. From 4.0.2 to 5.0.2, the overall improvement of the build time is from about 30% to 50%. From 5.0.2 to 6.0, the time of incremental build with large change set improved more than 20%. Links to the individual pages are provided for the detailed build activities.

Change a copybook file and execute build

Detailed build activities comparison for this test scenario "Change a copybook file and execute build" can be found here.

Change a COBOL file and execute build

Detailed build activities comparison for this test scenario "Change a COBOL file and execute build" can be found here.

Change all copybook files and execute build

Detailed build activities comparison for this test scenario "Change all copybook files and execute build" can be found here.

Change all COBOL files and execute build

Detailed build activities comparison for this test scenario "Change all COBOL files and execute build" can be found here.

Appendix A - Key Tuning Parameters

 -Xmn512m -Xgcpolicy:gencon -Xcompressedrefs -Xgc:preferredHeapBase=0x100000000
 -Xmx4g -Xms4g

* hard nofile 120000                    
* soft nofile 120000

About the authors

SuHui LuLu

Questions and comments:

• What other performance information would you like to see here?
• Do you have performance scenarios to share?
• Do you have scenarios that are not addressed in documentation?
• Where are you having problems in performance?

Warning: Can't find topic Deployment.PerformanceDatasheetReaderComments