com.mesosphere.sdk.offer.evaluate.placement

Class RoundRobinByHostnameRule

java.lang.Object

com.mesosphere.sdk.offer.evaluate.placement.AbstractRoundRobinRule

com.mesosphere.sdk.offer.evaluate.placement.RoundRobinByHostnameRule

All Implemented Interfaces:

PlacementRule

public class RoundRobinByHostnameRule
extends AbstractRoundRobinRule

Implements logic for Marathon's GROUP_BY operator for hostnames. Ensures that tasks are evenly distributed across agents in the system as they are rolled out. Example: hostname | tasks ----------+--------------- host-1 | a-1, b-1, c-1 host-2 | a-2, c-2, c-3 host-3 | b-2, c-4 Result: allow (only) host-3, unless we know that there's >=4 hosts via the agent-count parameter Example: hostname | tasks ----------+--------------- host-1 | a-1, b-1, c-1 host-2 | a-2, c-2, c-3 host-3 | b-2, c-4, b-3 Result: allow any of host-1/host-2/host-3, unless we know that there's >=4 hosts via the agent-count parameter. This enforcement is applied by task name. By default the rule will only count e.g. tasks named 'index-.*'. This allows us to only enforce the rule against certain task types or task instances within the service.

Field Summary

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

distinctKeyCount, taskFilter

Constructor Summary

Constructors

Constructor and Description
RoundRobinByHostnameRule(java.util.Optional<java.lang.Integer> agentCount)
RoundRobinByHostnameRule(java.util.Optional<java.lang.Integer> agentCount, StringMatcher taskFilter)

Method Summary

Modifier and Type	Method and Description
protected java.lang.String	getKey(Offer offer) Returns a value to round robin against from the provided Offer.
protected java.lang.String	getKey(TaskInfo task) Returns a value to round robin against from the provided 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.AbstractRoundRobinRule

equals, filter, hashCode

Methods inherited from class java.lang.Object

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

Constructor Detail

RoundRobinByHostnameRule

public RoundRobinByHostnameRule(java.util.Optional<java.lang.Integer> agentCount)

RoundRobinByHostnameRule

public RoundRobinByHostnameRule(java.util.Optional<java.lang.Integer> agentCount,
                                StringMatcher taskFilter)

Method Detail

getKey

protected java.lang.String getKey(Offer offer)

Returns a value to round robin against from the provided Offer.

Specified by:

getKey in class AbstractRoundRobinRule

getKey

protected java.lang.String getKey(TaskInfo task)

Returns a value to round robin against from the provided TaskInfo.

Specified by:

getKey in class AbstractRoundRobinRule

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

getPlacementFields

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

Description copied from interface: PlacementRule

Returns the PlacementFields to which this rule applies.