org.apache.storm.scheduler.resource.strategies.scheduling

Class ConstraintSolverStrategy

java.lang.Object

org.apache.storm.scheduler.resource.strategies.scheduling.BaseResourceAwareStrategy

org.apache.storm.scheduler.resource.strategies.scheduling.ConstraintSolverStrategy

All Implemented Interfaces:

IStrategy

public class ConstraintSolverStrategy
extends BaseResourceAwareStrategy

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.storm.scheduler.resource.strategies.scheduling.BaseResourceAwareStrategy

BaseResourceAwareStrategy.NodeSortType

Field Summary

Fields inherited from class org.apache.storm.scheduler.resource.strategies.scheduling.BaseResourceAwareStrategy

cluster, compToExecs, config, execSorter, execToComp, nodes, nodeSorter, nodeSortType, orderExecutorsByProximity, searcherState, sortNodesForEachExecutor, topologyDetails, topoName

Constructor Summary

Constructors

Constructor and Description
ConstraintSolverStrategy()

Method Summary

Modifier and Type	Method and Description
protected SchedulingResult	checkSchedulingFeasibility() Check scheduling feasibility for a quick failure as the second step in BaseResourceAwareStrategy.schedule(Cluster, TopologyDetails).
protected boolean	isExecAssignmentToWorkerValid(ExecutorDetails exec, WorkerSlot worker) Check if any constraints are violated if exec is scheduled on worker.
protected void	prepareForScheduling(Cluster cluster, TopologyDetails topologyDetails) Initialize instance variables as the first step in BaseResourceAwareStrategy.schedule(Cluster, TopologyDetails).
static boolean	validateSolution(Cluster cluster, TopologyDetails topo) Determines if a scheduling is valid and all constraints are satisfied (for use in testing).

Methods inherited from class org.apache.storm.scheduler.resource.strategies.scheduling.BaseResourceAwareStrategy

assignBoundAckersForNewWorkerSlot, getMaxStateSearchFromTopoConf, hostnameToNodes, idToNode, isOrderByProximity, prepare, schedule, scheduleExecutorsOnNodes, setExecSorter, setNodeSorter

Methods inherited from class java.lang.Object

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

Constructor Detail

ConstraintSolverStrategy

public ConstraintSolverStrategy()

Method Detail

prepareForScheduling

protected void prepareForScheduling(Cluster cluster,
                                    TopologyDetails topologyDetails)

Description copied from class: BaseResourceAwareStrategy

Initialize instance variables as the first step in BaseResourceAwareStrategy.schedule(Cluster, TopologyDetails). This method may be extended by subclasses to initialize additional variables as in prepareForScheduling(Cluster, TopologyDetails).

Overrides:

prepareForScheduling in class BaseResourceAwareStrategy

Parameters:

cluster - on which executors will be scheduled.

topologyDetails - to be scheduled.

checkSchedulingFeasibility

protected SchedulingResult checkSchedulingFeasibility()

Description copied from class: BaseResourceAwareStrategy

Check scheduling feasibility for a quick failure as the second step in BaseResourceAwareStrategy.schedule(Cluster, TopologyDetails). If scheduling is not possible, then return a SchedulingStatus object with a failure status. If fully scheduled then return a successful SchedulingStatus. This method can be extended by subclasses checkSchedulingFeasibility() to check for additional failure conditions.

Overrides:

checkSchedulingFeasibility in class BaseResourceAwareStrategy

Returns:

A non-null SchedulingResult to terminate scheduling, otherwise return null to continue scheduling.

isExecAssignmentToWorkerValid

protected boolean isExecAssignmentToWorkerValid(ExecutorDetails exec,
                                                WorkerSlot worker)

Check if any constraints are violated if exec is scheduled on worker.

Overrides:

isExecAssignmentToWorkerValid in class BaseResourceAwareStrategy

Parameters:

exec - being scheduled.

worker - on which to schedule.

Returns:

true if scheduling exec on worker does not violate any constraints, returns false if it does

validateSolution

public static boolean validateSolution(Cluster cluster,
                                       TopologyDetails topo)

Determines if a scheduling is valid and all constraints are satisfied (for use in testing). This is done in three steps.

Check if nodeCoLocationCnt-constraints are satisfied. Some components may allow only a certain number of executors to exist on the same node ConstraintSolverConfig.getMaxNodeCoLocationCnts(). Check if incompatibility-constraints are satisfied. Incompatible components ConstraintSolverConfig.getIncompatibleComponentSets() should not be put on the same worker. Check if CPU and Memory resources do not exceed availability on the node and total matches what is expected when fully scheduled.

Parameters:

cluster - on which scheduling was done.

topo - TopologyDetails being scheduled.

Returns:

true if solution is valid, false otherwise.