The following hot list contains recommendations that have improved performance or scalability, or both, for many applications.
Review the hardware and software requirements on the IBM WebSphere Application Server supported hardware, software, and APIs Web site to get started.
The list of recommended updates is maintained on the Support site.
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 that is used is the hardware that is supposed to be used.
You can track many performance problems back to the application design. Review the design to determine if it causes performance problems.
Operating system configuration plays a key role in performance. In many cases, adjustments to some TCP/IP parameters might be necessary for your application.
Many applications need a larger heap size for best performance.
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.
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.
See the Connection pooling topic for more information.
Use applications that can take advantage of the pass by reference option to avoid the cost of copying parameters to the stack.
In many cases, some other component, for example, a database, needs adjustments to achieve higher throughput for your entire configuration.
For more information, see the Queuing network topic.