usl (version 1.2.1)

scalability: Scalability function of a USL model

Description

scalability is a higher order function and returns a function to calculate the scalability for the specific USL model.

Usage

## S3 method for class 'USL':
scalability(object, sigma, kappa)

Arguments

object

A USL object.

sigma

Optional parameter to be used for evaluation instead of the parameter computed for the model.

kappa

Optional parameter to be used for evaluation instead of the parameter computed for the model.

Value

• A function with parameter x that calculates the scalability value of the specific model.

Details

The returned function can be used to calculate specific values once the model for a system has been created.

The parameters sigma or kappa are useful to do a what-if analysis. Setting these parameters override the model parameters and show how the system would behave with a different contention or coherency delay parameter.

References

Neil J. Gunther. Guerrilla Capacity Planning: A Tactical Approach to Planning for Highly Scalable Applications and Services. Springer, Heidelberg, Germany, 1st edition, 2007.

See Also

usl, peak.scalability

Examples

require(usl)

data(raytracer)

## Compute the scalability function
s <- scalability(usl(throughput ~ processors, raytracer))

## Print scalability for 32 CPUs for the demo dataset
print(s(32))

## Plot scalability for the range from 1 to 64 CPUs
plot(s, from=1, to=64)