Professional SQL Server® 2008 Internals and Troubleshooting

Chapter 12. Introducing RML Utilities for Stress Testing and Trace File Analysis

WHAT'S IN THIS CHAPTER

• How and when to use RML Utilities

• Using RML Utilities to replay workload

• Ensuring fair and representative replay testing

Like many of the utilities presented in this book, the RML Utilities are a set of tools originally developed by the SQL Server support organization within Microsoft to help engineers effectively resolve customer support incidents. The RML Utilities consist of four key components: ReadTrace, OStress, ORCA, and Reporter. When combined, these utilities enable developers and administrators to replay workload, identify problems, and compare performance.

The high-level process to generate real production workload on a test server is as follows:

1. Capture a trace on a production server.

2. Convert the trace with ReadTrace.

3. Replay the trace on the test server using OStress.

The Replay Markup Language (RML) is an XML-like language that can be used to replay workload against a SQL Server. A trace containing the statements executed against a server are captured using SQL Server Profiler, then ReadTrace is used to convert the .TRC (profiler trace output) to .RML files, which can then be replayed using OStress.

It can be difficult to simulate production workload in a test environment, and RML Utilities addresses this challenge. In addition to providing a testing platform, the tools within RML Utilities can provide powerful insight into performance data. Moreover, the tools are easy to ...