Editing Performance tuning (section)

{{Refimprove|date=July 2016}}
'''Performance tuning''' is the improvement of [[system]] [[Computer performance|performance]]. Typically in computer systems, the motivation for such activity is called a performance problem, which can be either real or anticipated. Most systems will respond to increased [[Load (computing)|load]] with some degree of decreasing performance. A system's ability to accept higher load is called [[scalability]], and modifying a system to handle a higher load is synonymous to performance tuning.

Systematic tuning follows these steps:
# Assess the problem and establish numeric values that categorize acceptable behavior.
# Measure the performance of the system before modification.
# Identify the part of the system that is critical for improving the performance. This is called the [[bottleneck (software)|bottleneck]].
# Modify that part of the system to remove the bottleneck.
# Measure the performance of the system after modification.
# If the modification makes the performance better, adopt it. If the modification makes the performance worse, put it back the way it was.

This is an instance of the measure-evaluate-improve-learn cycle from [[quality assurance]].

A performance problem may be identified by slow or unresponsive systems. This usually occurs because high system [[Load (computing)|loading]], causing some part of the system to reach a limit in its ability to respond. This limit within the system is referred to as a bottleneck.

A handful of techniques are used to improve performance. Among them are code optimization, load balancing, caching strategy, distributed computing and self-tuning.