com.mesosphere.sdk.offer.evaluate.placement

Class MaxPerHostnameRule

java.lang.Object

com.mesosphere.sdk.offer.evaluate.placement.MaxPerRule

com.mesosphere.sdk.offer.evaluate.placement.MaxPerHostnameRule

All Implemented Interfaces:

PlacementRule

public class MaxPerHostnameRule
extends MaxPerRule

Ensures that no more than N instances of a task type are running on a given hostname (or hostname pattern). For example, this can ensure that no more than N tasks are running against the 'rack:foo' attribute (exact match), or it can ensure that no distinct 'rack:.*' value has more than N tasks running against it (wildcarded grouping). To illustrate, let's look at a deployment scenario of 3 hosts with the following tasks: hostname | tasks ----------+--------------- host-1 | a-1, b-1, c-1 host-2 | a-2, c-2, c-3 host-3 | b-2, c-4 In this example, let's assume a MaxPerHostnameRule with a limit of 2 and a regex of 'c-.*'. In this case, we're ensuring that no more than 2 tasks starting with 'c-' can be launched on any given host. Among the above three hosts, any offers from host-1 and host-3 will be accepted and offers from host-2 will be denied.

Field Summary

Fields inherited from class com.mesosphere.sdk.offer.evaluate.placement.MaxPerRule

max

Constructor Summary

Constructors

Constructor and Description
MaxPerHostnameRule(int maxTasksPerSelectedHostname) Creates a new rule which will block deployment on tasks which already have N instances running against a specified attribute, with no filtering on task names (all tasks across the service are counted against the max).
MaxPerHostnameRule(int maxTasksPerSelectedHostname, StringMatcher taskFilter) Creates a new rule which will block deployment on tasks which already have N instances running against a specified hostname.

Method Summary

Modifier and Type	Method and Description
EvaluationOutcome	filter(Offer offer, PodInstance podInstance, java.util.Collection<TaskInfo> tasks) Returns whether the provided Offer, combined with the accompanying TaskInfos, passes or fails this placement constraint.
java.util.Collection<java.lang.String>	getKeys(Offer offer)
java.util.Collection<java.lang.String>	getKeys(TaskInfo taskInfo)
java.util.Collection<PlacementField>	getPlacementFields() Returns the PlacementFields to which this rule applies.
java.lang.String	toString()

Methods inherited from class com.mesosphere.sdk.offer.evaluate.placement.MaxPerRule

equals, getTaskFilter, hashCode, isAcceptable

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

MaxPerHostnameRule

public MaxPerHostnameRule(int maxTasksPerSelectedHostname)

Creates a new rule which will block deployment on tasks which already have N instances running against a specified attribute, with no filtering on task names (all tasks across the service are counted against the max).

Parameters:

maxTasksPerSelectedHostname - the maximum number of tasks which may be run on a selected agent

MaxPerHostnameRule

public MaxPerHostnameRule(int maxTasksPerSelectedHostname,
                          StringMatcher taskFilter)

Creates a new rule which will block deployment on tasks which already have N instances running against a specified hostname.

Parameters:

maxTasksPerSelectedHostname - the maximum number of tasks which may be run on a selected agent

taskFilter - a filter on task names to determine which tasks are included in the count, for example counting all tasks, or just counting tasks of a given type

Method Detail

filter

public EvaluationOutcome filter(Offer offer,
                                PodInstance podInstance,
                                java.util.Collection<TaskInfo> tasks)

Description copied from interface: PlacementRule

Returns whether the provided Offer, combined with the accompanying TaskInfos, passes or fails this placement constraint.

Parameters:

offer - the offer to be examined

tasks - the currently deployed tasks in the system, possibly including a duplicate of the task being launched as represented in the offerRequirement. Use PlacementUtils.areEquivalent(TaskInfo, PodInstance) to detect duplicates

Returns:

an EvaluationOutcome object describing whether the placement succeeded or failed and why

getPlacementFields

public java.util.Collection<PlacementField> getPlacementFields()

Description copied from interface: PlacementRule

Returns the PlacementFields to which this rule applies.

getKeys

public java.util.Collection<java.lang.String> getKeys(TaskInfo taskInfo)

Specified by:

getKeys in class MaxPerRule

getKeys

public java.util.Collection<java.lang.String> getKeys(Offer offer)

Specified by:

getKeys in class MaxPerRule

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object