com.mesosphere.sdk.scheduler.decommission

Class DecommissionPlanFactory

java.lang.Object

com.mesosphere.sdk.scheduler.decommission.DecommissionPlanFactory

public class DecommissionPlanFactory
extends java.lang.Object

Handles creation of the decommission plan, used for removing nodes from a service. The plan is structured as a series of phases, one per pod to be decommissioned. Each pod will be decommissioned as follows:

1. Tasks in the pod are set to a DECOMMISSIONED+IN_PROGRESS state, from DECOMMISSIONED+PENDING which was set when the Plan was initialized.
2. Kill is issued for all tasks in the pod.
3. As resources for tasks within the pod are offered, the DECOMMISSIONED+IN_PROGRESS state results in those resources being unreserved and removed from the TaskInfo.
4. Once the resources are all cleared, the task is deleted from the StateStore.

Note that this is different from uninstall behavior in a couple ways, resulting in different handling from uninstall:

• The decommission operation can be cancelled by incrementing pod count, whereas uninstall cannot be cancelled once it's started. We remove resources from the TaskInfos instead of marking them with tombstones to reduce the likelihood of a partial decommission causing problems.
• The decommission operation occurs serially in a predictable order, whereas uninstall attempts to unreserve all known resources in parallel. We enforce this by having the decommission plan set the DECOMMISSIONED+IN_PROGRESS bit one pod at a time, and only unreserve pods that are marked as DECOMMISSIONED+IN_PROGRESS.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
(package private) static class	DecommissionPlanFactory.PodKey A utility class for ordering a SortedMap of pods to be decommissioned.

Field Summary

Fields

Modifier and Type	Field and Description
static GoalStateOverride.Status	DECOMMISSIONING_STATUS The status for a task whose resources should be unreserved because its resources are currently being decommissioned.

Constructor Summary

Constructors

Constructor and Description
DecommissionPlanFactory(ServiceSpec serviceSpec, StateStore stateStore, TaskKiller taskKiller)

Method Summary

Modifier and Type	Method and Description
java.util.Optional<Plan>	getPlan() Returns a Plan for decommissioning tasks, or an empty Optional if nothing needs to be decommissioned.
(package private) static java.util.SortedMap<DecommissionPlanFactory.PodKey,java.util.Collection<Protos.TaskInfo>>	getPodsToDecommission(ServiceSpec serviceSpec, java.util.Collection<Protos.TaskInfo> tasks) Returns a mapping of pods to be decommissioned with affected tasks within those pods.
java.util.Collection<Step>	getResourceSteps() Returns all ResourceCleanupSteps associated with the decommission plan, or an empty list if no steps are applicable.

Methods inherited from class java.lang.Object

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

Field Detail

DECOMMISSIONING_STATUS

public static final GoalStateOverride.Status DECOMMISSIONING_STATUS

The status for a task whose resources should be unreserved because its resources are currently being decommissioned.

Constructor Detail

DecommissionPlanFactory

public DecommissionPlanFactory(ServiceSpec serviceSpec,
                               StateStore stateStore,
                               TaskKiller taskKiller)

Method Detail

getPlan

public java.util.Optional<Plan> getPlan()

Returns a Plan for decommissioning tasks, or an empty Optional if nothing needs to be decommissioned.

getResourceSteps

public java.util.Collection<Step> getResourceSteps()

Returns all ResourceCleanupSteps associated with the decommission plan, or an empty list if no steps are applicable.

getPodsToDecommission

static java.util.SortedMap<DecommissionPlanFactory.PodKey,java.util.Collection<Protos.TaskInfo>> getPodsToDecommission(ServiceSpec serviceSpec,
                                                                                                                       java.util.Collection<Protos.TaskInfo> tasks)

Returns a mapping of pods to be decommissioned with affected tasks within those pods. The returned mapping will be in the order that the pods should be decommissioned.