Modelling and applications sizing

Workload Management

Demand Management

Demand Management is the name given to a number of techniques that can be used to modify demand for a particular resource or service. Some techniques for Demand Management can be planned in advance– and these are covered in more detail in the Service Design publication. However, there are other aspects of Demand Management that are of a more operational nature, requiring shorter-term action.

If, for example, the performance of a particular service is causing concern, and short-term restrictions on concurrency of user s are needed to allow performance improvements for a smaller restricted group, then Service Operation function s will have to take action to implement such restrictions – usually accompanied by concurrent action to implement the logging-out of users who have been inactive for an agreed period of time to free up resources for others.

There may be occasions when optimization of infrastructure resources is needed to maintain or improve performance or throughput. This can often be done through Workload Management, which is a generic term to cover such actions as:

• Rescheduling a particular service or workload to run at a different time of day, or day of the week etc. (usually away from peak-times to off-peak windows) – which will often mean having to make adjustments to job-scheduling software.
• Moving a service or workload from one location or set of CIs to another – often to balance utilization or traffic.
• Technical Virtualization: setting up and using virtualization systems to allow movement of processing around the infrastructure to give better performance/ resilience in a dynamic fashion.
• Limiting or moving demand for resources through Demand Management techniques (see above and also the Service Design publication).

It will only be possible to manage workloads effectively if a good understanding exists of which workloads will run at what time and how much resource utilization each workload places upon the IT Infrastructure. Diligent monitoring and analysis of workload s is therefore needed on an ongoing operational basis.

Modelling and/or sizing of new services and/or application s must, where appropriate, be done during the planning and transition phases – see the Service Design and Service Transition publications. However, the Service Operation function s have a role to play in evaluating the accuracy of the predictions and feeding back any issues or discrepancies.

Дата добавления: 2014-12-23