Db2 Buffer Pool Tuning: How do you know if your Db2 buffer pools are tuned?

Db2 for z/OS and vendor products collect and report on several buffer pool characteristics. Db2 statistics (SMF 100 records) and accounting (SMF 101) records can provide buffer pool performance information at the subsystem and thread level. Db2 can externalize multiple IFCIDs (198, 199, 201, and 202) with detailed buffer pools and object information.

Focus on the following metrics when looking at buffer pool performance; they will give you a good idea of overall buffer pool health:

In addition to these watching these metrics, it’s important to monitor adverse events occurring in the Db2 subsystem, including

Buffer Pool Performance Tuning Tools

Buffer pool performance management can be a challenge, but tools are available to help you. These tools fall into two groups: general purpose monitors and buffer pool tools. (BMC System Performance for Db2 provides both types of tools.)

Db2 performance monitors monitor buffer pools in real time and may provide near and long-term historical reporting capabilities. Monitors report Db2 accounting and statistics data about buffer pool performance. Monitors can capture many adverse events, and you can use automation capabilities to respond to these problems. Detailed analysis of buffer pool configurations is typically not provided. Depending on your environment, this may be the only type of Db2 buffer pool monitoring tool you need.

For other Db2 environments, “deep-dive” products provide extensive monitoring and analysis. These tools collect and report on real-time performance metrics and maintain detailed historical performance data that can provide long term analysis of buffer pool performance to help you identify and respond to negative trends. These tools also recommend buffer pool configuration changes including number and size of pools, thresholds, and Db2 object placement.