Performance testing and tuning

There is a strong relationship between performance testing and tuning, in the
sense that one often leads to the other. Often, end-to-end testing unveils system
or application bottlenecks that are regarded as unacceptable for project target goals. Once those bottlenecks are discovered, the next step for most teams is a series of tuning efforts to make the application perform adequately.

Such efforts normally include, but are not limited to, the following:

• Configuring changes in system resources
• Optimizing database queries
• Reducing round trips in application calls, sometimes leading to redesigning and re-architecting problematic modules
• Scaling out application and database server capacity
• Reducing application resource footprint
• Optimizing and refactoring code, including eliminating redundancy and reducing execution time

Tuning efforts may also commence if the application has reached acceptable performance but the team wants to reduce the amount of system resources being
used, decrease the volume of hardware needed, or further increase system performance.

After each change (or series of changes), the test is re-executed to see whether the performance has improved or declined due to the changes. The process
will be continued with the performance results having reached acceptable goals.
The outcome of these test-tuning circles normally produces a baseline.