Tuning parameter hot list
WebSphere Application Server provides several tunable parameters and options to match the application server environment to the requirements of your application. The following hot list contains recommendations that have proved performance or scalability, or both, for many applications.
- Check hardware configuration and settings
Check network connections to make sure that they are running at their highest speed. Sometimes transient errors can cause Ethernet adapters to shift down to a lower speed. Verify that the system has adequate memory and that the number and position of memory dual inline memory module (DIMM) are optimal. With some systems, there are some memory DIMM configurations that permit higher performance than other DIMM configurations. Verify that the hardware which is used is the hardware that is supposed to be used.
- Review your application design
We can track many performance problems back to the application design. Review the design to determine if it causes performance problems.
- Tune the operating systems
Operating system configuration plays a key role in performance. In many cases, adjustments to some TCP/IP parameters might be necessary for your application.
- Set the minimum and maximum Java virtual machine (JVM) heap sizes
Many applications need a larger heap size for best performance.
- Use a type 4 (or pure Java) JDBC driver
The type 4 JDBC drivers generally perform faster than type 2 JDBC drivers. Use the immediately preceding link to view a list of database vendor-specific requirements, which can tell you if a type 4 JDBC driver is supported for your database.
- Tune WebSphere Application Server JDBC data sources and associated connection pools
The JDBC data source configuration might have a significant performance impact. For example, the connection pool size and prepared statement cache need to be sized based on the number of concurrent requests being processed and the design of the application.
- Enable the pass by reference option
Applications that can take advantage of the pass by reference option to avoid the cost of copying parameters.
- Ensure that the transaction log is assigned to a fast disk
Some applications generate a high rate of writes to the WAS transaction log. Locating the transaction log on a fast disk or disk array can improve response time
- Tune related components, for example, Web servers and databases
In many cases, some other component, for example, a Web server or databases needs adjustments to achieve higher throughput for your entire configuration.
Related Tasks
Tuning the application serving environment
Tuning Web servers
Task overview: Using the dynamic cache service to improve performance