com.netflix.fenzo.plugins

Class HostAttrValueConstraint

java.lang.Object

com.netflix.fenzo.plugins.HostAttrValueConstraint

All Implemented Interfaces:

ConstraintEvaluator

public class HostAttrValueConstraint
extends java.lang.Object
implements ConstraintEvaluator

A constraint that ensures that a task gets a host with an attribute of a specified value.

Nested Class Summary

Nested classes/interfaces inherited from interface com.netflix.fenzo.ConstraintEvaluator

ConstraintEvaluator.Result

Constructor Summary

Constructors

Constructor and Description
HostAttrValueConstraint(java.lang.String hostAttributeName, Func1<java.lang.String,java.lang.String> hostAttributeValueGetter)

Method Summary

Modifier and Type	Method and Description
ConstraintEvaluator.Result	evaluate(TaskRequest taskRequest, VirtualMachineCurrentState targetVM, TaskTrackerState taskTrackerState) Tests a host to determine whether it has an attribute of the required value for this task request.
java.lang.String	getName() Returns the name of this constraint as a String, in the form of the class name followed by a dash followed by the value of hostAttributeName as it was set when this object was constructed.

Methods inherited from class java.lang.Object

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

Constructor Detail

HostAttrValueConstraint

public HostAttrValueConstraint(java.lang.String hostAttributeName,
                               Func1<java.lang.String,java.lang.String> hostAttributeValueGetter)

Method Detail

getName

public java.lang.String getName()

Returns the name of this constraint as a String, in the form of the class name followed by a dash followed by the value of hostAttributeName as it was set when this object was constructed.

Specified by:

getName in interface ConstraintEvaluator

Returns:

the name of this constraint

evaluate

public ConstraintEvaluator.Result evaluate(TaskRequest taskRequest,
                                           VirtualMachineCurrentState targetVM,
                                           TaskTrackerState taskTrackerState)

Tests a host to determine whether it has an attribute of the required value for this task request.

Specified by:

evaluate in interface ConstraintEvaluator

Parameters:

taskRequest - describes the task being evaluated for assignment to the host

targetVM - describes the host being evaluated as a target for the task

taskTrackerState - describes the state of tasks already assigned or running on hosts throughout the system

Returns:

a successful Result if the host has an attribute with the required value, or an unsuccessful Result otherwise