Comparison
OverprovisioningvsRightsizing
Overprovisioning
every service asked for four cores because that is what the template said, and the fleet averages eight percent CPU.
Running more capacity than the workload needs, usually through copied defaults, fear of the last incident, or requests set from peak rather than from measurement. It is the largest single source of waste in most estates and the easiest to quantify, since utilisation data already exists. It is distinct from deliberate headroom, and telling the two apart is the first task of any cost exercise.
Full entry →Rightsizing
you look at a fortnight of real usage and cut the requests in half, and nothing at all happens.
Matching provisioned resources to observed usage plus deliberate headroom. It is unglamorous, repeatable and usually the single largest available saving, and it decays continuously as workloads change, so it is a recurring exercise rather than a project. The risk is rightsizing to an average and discovering the peak, which is why the percentile you size to should be a decision rather than an accident.
Full entry →