Class SimulatedResilienceObjective

java.lang.Object

com.eqixiac.equinix.design.resilience.SimulatedResilienceObjective

All Implemented Interfaces:

Objective

public final class SimulatedResilienceObjective
extends Object
implements Objective

"simulated_resilience": the share of a portfolio's baseline service that survives its worst single-element failure, 0 to 100, measured by building the design graph and simulating every metro, Cloud Router, on-ramp and connection loss (N1Survival). A workload's service is the site weight that still reaches it within its limits times the share of its bandwidth its cloud connections still carry, so "survives at 40% capacity" scores 40, not 100. Larger is better.

Richer than the built-in resilience objective (which only removes metros and counts what is left): it sees Cloud Routers, on-ramps, single connections, capacity and failover latency. Contributed by ResiliencePlugin; weight it in a spec with objectives.weights.simulated_resilience.

Field Summary

Fields

Modifier and Type	Field	Description
static final String	ID	The objective id.

Fields inherited from interface Objective

COMPLIANCE, COST, LATENCY, PROVIDER_COVERAGE, RESILIENCE

Modifier and Type	Field	Description
static final String	COMPLIANCE	Share of the stated compliance and sovereignty zones the portfolio satisfies, 0 to 100.
static final String	COST	Total monthly cost of the portfolio in the spec's currency.
static final String	LATENCY	Site-weighted round-trip latency from the sites to their nearest metro in the portfolio, in ms.
static final String	PROVIDER_COVERAGE	Share of the required clouds and service providers reachable from the portfolio, 0 to 100.
static final String	RESILIENCE	How well the portfolio survives losing a metro or a region, 0 to 100.

Constructor Summary

Constructors

Constructor	Description
SimulatedResilienceObjective()	Always evaluates, with the default options.
SimulatedResilienceObjective(ResilienceOptions options, boolean onlyWhenWeighted)

Method Summary

Modifier and Type	Method	Description
Direction	direction()
ObjectiveValue	evaluate(MetroPortfolio portfolio, DesignContext context)	Measures a portfolio.
String	id()
ValueScale	scale(DesignContext context)	A percentage is its own score.
String	unit()

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

ID

public static final String ID

The objective id.

See Also:

• Constant Field Values

Constructor Details

SimulatedResilienceObjective

public SimulatedResilienceObjective()

Always evaluates, with the default options.

SimulatedResilienceObjective

public SimulatedResilienceObjective(ResilienceOptions options,
 boolean onlyWhenWeighted)

Parameters:

options - graph and simulation options

onlyWhenWeighted - when true, a spec that gives "simulated_resilience" no positive weight (after its profile is applied) gets an unknown value without simulating, which keeps a large search fast; the explanation says so

Method Details

id

public String id()

Specified by:

id in interface Objective

Returns:

the id weights refer to (for example Objective.LATENCY); stable, lower_snake_case

direction

public Direction direction()

Specified by:

direction in interface Objective

Returns:

whether smaller or larger values are better

scale

public ValueScale scale(DesignContext context)

A percentage is its own score.

Specified by:

scale in interface Objective

Parameters:

context - the facts of this run

Returns:

the scale

unit

public String unit()

Specified by:

unit in interface Objective

Returns:

the unit of ObjectiveValue.value(), for display (for example ms, USD/month, score)

evaluate

public ObjectiveValue evaluate(MetroPortfolio portfolio,
 DesignContext context)

Description copied from interface: Objective

Measures a portfolio.

Specified by:

evaluate in interface Objective

Parameters:

portfolio - the metros of one candidate design

context - the facts of this run

Returns:

the measurement, or ObjectiveValue.unknown(String) when it cannot be made