Class LatencyObjective

java.lang.Object

com.eqixiac.equinix.design.objective.LatencyObjective

All Implemented Interfaces:

Objective

public final class LatencyObjective
extends Object
implements Objective

Site-weighted round-trip latency from each site to its nearest metro in the portfolio, in ms. Sites whose latency to every portfolio metro is unknown are left out and the weights of the rest renormalised; the explanation names them, the worst-case site, and whether its figure is measured. Unknown when no site latency is known.

Field Summary

Fields

Modifier and Type	Field	Description
static final double	DEFAULT_WORST_ROUND_TRIP_MS	The round trip that scores 0 when the spec states no latency ceiling, in ms.

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
LatencyObjective()

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 fixed scale: 0 ms scores 100 and the spec's latency ceiling scores 0, or 200.0 ms round trip when the spec states none (an SDK assumption: about where interactive traffic stops feeling local).
String	unit()

Methods inherited from class Object

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

Field Details

DEFAULT_WORST_ROUND_TRIP_MS

public static final double DEFAULT_WORST_ROUND_TRIP_MS

The round trip that scores 0 when the spec states no latency ceiling, in ms.

See Also:

• Constant Field Values

Constructor Details

LatencyObjective

public LatencyObjective()

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 fixed scale: 0 ms scores 100 and the spec's latency ceiling scores 0, or 200.0 ms round trip when the spec states none (an SDK assumption: about where interactive traffic stops feeling local). A few milliseconds therefore cost a few points, whatever other options are in the set.

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