Java Performance Tuning

Starting to Tune

Before diving into the actual tuning, there are a number of considerations that will make your tuning phase run more smoothly and result in clearly achieved objectives.

User Agreements

Any application must meet the needs and expectations of its users, and a large part of those needs and expectations is performance. Before you start tuning, it is crucial to identify the target response times for as much of the system as possible. At the outset, you should agree with your users (directly if you have access to them, or otherwise through representative user profiles, market information, etc.) what the performance of the application is expected to be.

The performance should be specified for as many aspects of the system as possible, including:

• Multiuser response times depending on the number of users (if applicable)

• Systemwide throughput (e.g., number of transactions per minute for the system as a whole, or response times on a saturated network, again if applicable)

• The maximum number of users, data, files, file sizes, objects, etc., the application supports

• Any acceptable and expected degradation in performance between minimal, average, and extreme values of supported resources

Agree on target values and acceptable variances with the customer or potential users of the application (or whoever is responsible for performance) before starting to tune. Otherwise, you will not know where to target your effort, how far you need to go, whether particular performance targets are ...