CLM reliability report: CLM 4.0.5 release

Introduction

Reliability testing is about exercising the CLM applications so that failures are discovered and removed before the system is deployed. There are many different combinations of alternate pathways through the complex CLM application, this test scenario exercises the most likely use cases (explained in detail below). The use cases are put under constant load for a seven day period to validate that the CLM application provides the expected level of service, without any downtime or degradation in overall system performance. This report is a sample of the results from a recent CLM 405 Reliability test.

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

Performance goals

Primary Goals - Detection

• Test the CLM software performance under given conditions, and monitoring for any degradation in performance over the course of the 7 day run.
• Monitor for increases in the overall page or page element averages.
• Report on any specific page which increases over time.

Secondary Goals - Analysis

• To discover the main cause of any failure.
• To find and correlate the structure of repeating failures.

Findings

• Completion of 7 day run without any crashes or noticeable degradation in performance.
• Several page transactions were visibly increasing in response time over the seven day period. Further analysis of these specific transaction will be conducted.
• Final load results will be further analyzed to determine if the actual load fits within our anticipated scalability needs.

Topology

The topology under test is based on Standard Topology (E1) Enterprise - Distributed / Linux / DB2.

The specifications of machines under test are listed in the table below. Server tuning details listed in Appendix A

Network connectivity

All CLM server machines and RPT test driver machines are located on the same subnet. The LAN has 1000 Mbps of maximum bandwidth, and the average latency between the IHS server and all distributed Application Servers is 1.12ms. The LDAP Server is also on the same subnet, but has a latency of less than 0.8ms with the CLM Servers.

Data volume and shape

At the beginning of the test the repository projects were populated to have the following size:

RM/DNG - 10 projects with 100K artifacts CCM - 10 projects populated with 100K artifacts QM - 10 projects populated with 100K artifacts Admin – 10 CLM projects with artifacts linked across all projects

Methodology

Rational Performance Tester was used to simulate the CLM workload created using the web client. Each user is distributed across a set of user groups. Each user group represents a CLM product area, e.g. CCM, QM, RM. Each user group performs a random set of use cases from a set of available use cases. A Rational Performance Tester script is created for each use case. The scripts are organized by pages and each page represents a single user action.

Based on real customer use, the CLM test scenario provides a ratio of 70% reads and 30% writes. The users completed use cases at a rate of 6.25 pages per second, over a seven day period. Each CLM performance test runs for seven days with no decline in usage or other downtime.

The total CLM workload distribution is 45% CCM, 30% QM, 10% Integrations, 5% DNG Web, and 10% RM. Test cases with the higher weights will be run more frequently within the User Groups.

CLM test cases and weighted distribution

Results

IHS Thread Analysis

IHS threads usage is monitored to determine how well IHS server was keeping up with the load, and determine if IHS was tuned properly to move the threads through the system most efficiently. The following chart shows how well the IHS server was handling it's threads, and of note are the threads in WAS module which do not accumulate over time which indicates the WebSphere Application servers are keeping up with the load. IHS server-status command monitoring indicates the webserver is processing approximately 91.4 requests/sec.

RPT Page Hit Rate

RPT Page Hit Rate is captured to monitor the load and help with correlation of any incidences where load changes. For purposes of this test the load is constant.

RPT Page Element Response over Time

Page Element Response Rate is captured to monitor the average page element response over time.

RPT Average Page Response Time

RPT Average Page Response Time shows the average of all pages over time. This is very useful in determining which if/any pages are unexpectedly increasing in response time over the seven day period. For example, two page response times appear to be steadily increasing, so further analysis of these two page transactions will be performed to determine if they are a result of a test design issue, with increasing data volumes pushing up response times, or if this is indeed a product issue.

The two tests under investigation here are "RQM_TestCase_SelectPickFolder", and "RRC_Collection_SelectPickFolder". The RQM_TestCase_SelectPickFolder is a page which is part of the process of creating a new RM requirement in a specific folder from within a new RQM Testcase. The second page RRC_Collection_SelectPickFolder is part of the use case where an RQM Quality Plan is validated by a new RM requirements collection that is created from within RQM.

RPT Byte Transfer Rate

RPT Byte Transfer Rate shows us if bytes being sent or received are changing over time, indicating a drop in throughput.

Appendix A

 -Xgcpolicy:gencon -Xmx8g -Xms8g -Xmn1g -Xcompressedrefs -Xgc:preferredHeapBase=0x100000000 -XX:MaxDirectMemorySize=1g

 -Xgcpolicy:gencon -Xmx8g -Xms4g -Xmn512m -Xcompressedrefs -Xgc:preferredHeapBase=0x100000000 -XX:MaxDirectMemorySize=1g

 -Xgcpolicy:gencon -Xmx4g -Xms4g -Xmn512m -Xcompressedrefs -Xgc:preferredHeapBase=0x100000000 -XX:MaxDirectMemorySize=1g

 -Xgcpolicy:gencon -Xmx4g -Xms4g -Xmn512m -Xcompressedrefs -Xgc:preferredHeapBase=0x100000000 -XX:MaxDirectMemorySize=1g

Garbage collection

Verbose garbage collection analysis helps determine how the memory and garbage collection are performing for the CLM applications running our use cases. Optimal JVM configuration depends very greatly on the usage pattern. Our goal is to provide guidance on where to start and what key tuning factors impact performance.

JTS

CCM

QM

RM

For more information

• Collaborative Lifecycle Management 2012 Sizing Report (Standard Topology E1)

About the authors

MarkGravina

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