Performance

Performance refers to the way in which a system performs or functions given a particular workload.

Performance is typically measured in terms of response time, throughput and availability.

Response time is the elapsed time between a submitted request and the response from the return request. Examples include the time taken by a database query, or the time taken to display a retrieved document.

Throughput is a measure of the amount of work over a period of time. In other words, it is the number of workload operations that can be accomplished per unit of time. Examples include database transactions per minute, kilobytes of a file transferred per second, total number of legacy documents imported per hour.

Performance problems may be caused by poor application and system design; inadequate system resources such as CPU, memory, disks, and non-optimal tuning of system resources.

Performance tuning can be performed to improve the performance. It is a complex and iterative process. It involves establishing quantitative objectives, constant system monitoring, and selective and careful tuning to ensure that the objectives are met over time.