The following hot list contains recommendations that have improved performance or scalability, or both, for many applications.
It is critical for proper functionality and performance to satisfy the minimum hardware and software requirements. Refer to IBM® WebSphere Application Server supported hardware, software, and APIs website which details hardware and software requirements.
The list of recommended updates is maintained on the Support site.
Verify network interconnections and hardware configuration is setup for peak performance.
Operating system configuration plays a key role in performance. For example, adjustments such as TCP/IP parameters might be necessary for your application
Many applications need a larger heap size then the default for best performance. It is also advised to select an appropriate GC policy based on the application's characteristics.
In general, the type 2 JDBC driver is recommended if the database exists on the same physical machine as the WebSphere instance. However, in the case where the database is in a different tier, the type 4 JDBC driver offers the fastest performance since they are pure Java not requiring native implementation. Use the link above 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 example, if your application does not use the web services addressing (WS-Addressing) support, disabling this function can improve performance.
Attention: Use this property with care because applications might require WS-Addressing MAPs to function correctly. Setting this property also disables WebSphere Application Server support for the following specifications, which depend on the WS-Addressing support: Web Services Atomic Transactions, Web Services Business Agreement and Web Services Notification.
To disable the support for WS-Addressing, refer to Enabling Web Services Addressing support for JAX-RPC applications
You can track many performance problems back to the application design. Review the design to determine if it causes performance problems.