org.gridgain.grid.kernal.visor.cmd

Class VisorMultiNodeTask<A,R,J>

java.lang.Object

org.gridgain.grid.kernal.visor.cmd.VisorMultiNodeTask<A,R,J>

Type Parameters:

A - Task argument type.

R - Task result type.

All Implemented Interfaces:

Serializable, GridComputeTask<GridBiTuple<Set<UUID>,A>,R>

Direct Known Subclasses:

VisorAckTask, VisorCacheCollectMetricsTask, VisorEventsCollectTask, VisorGcTask, VisorLicenseCollectTask, VisorOneNodeTask

public abstract class VisorMultiNodeTask<A,R,J>
extends Object
implements GridComputeTask<GridBiTuple<Set<UUID>,A>,R>

Base class for Visor tasks intended to query data from a multiple node.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected A	taskArg Task argument.

Constructor Summary

Constructors

Constructor and Description
VisorMultiNodeTask()

Method Summary

Methods

Modifier and Type	Method and Description
protected abstract VisorJob<A,J>	job(A arg)
Map<? extends GridComputeJob,GridNode>	map(List<GridNode> subgrid, GridBiTuple<Set<UUID>,A> arg) This method is called to map or split grid task into multiple grid jobs.
GridComputeJobResultPolicy	result(GridComputeJobResult res, List<GridComputeJobResult> rcvd) Asynchronous callback invoked every time a result from remote execution is received.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.gridgain.grid.compute.GridComputeTask

reduce

Field Detail

taskArg

protected A taskArg

Task argument.

Constructor Detail

VisorMultiNodeTask

public VisorMultiNodeTask()

Method Detail

job

protected abstract VisorJob<A,J> job(A arg)

Parameters:

arg - Task arg.

Returns:

New job.

map

@Nullable
public Map<? extends GridComputeJob,GridNode> map(List<GridNode> subgrid,
                                                  @Nullable
                                                  GridBiTuple<Set<UUID>,A> arg)
                                           throws GridException

This method is called to map or split grid task into multiple grid jobs. This is the first method that gets called when task execution starts.

Specified by:

map in interface GridComputeTask<GridBiTuple<Set<UUID>,A>,R>

Parameters:

subgrid - Nodes available for this task execution. Note that order of nodes is guaranteed to be randomized by container. This ensures that every time you simply iterate through grid nodes, the order of nodes will be random which over time should result into all nodes being used equally.

arg - Task execution argument. Can be null. This is the same argument as the one passed into Grid#execute(...) methods.

Returns:

Map of grid jobs assigned to subgrid node. Unless GridComputeTaskContinuousMapper is injected into task, if null or empty map is returned, exception will be thrown.

Throws:

GridException - If mapping could not complete successfully. This exception will be thrown out of GridComputeTaskFuture.get() method.

result

public GridComputeJobResultPolicy result(GridComputeJobResult res,
                                List<GridComputeJobResult> rcvd)
                                  throws GridException

Asynchronous callback invoked every time a result from remote execution is received. It is ultimately upto this method to return a policy based on which the system will either wait for more results, reduce results received so far, or failover this job to another node. See GridComputeJobResultPolicy for more information about result policies.

Specified by:

result in interface GridComputeTask<GridBiTuple<Set<UUID>,A>,R>

Parameters:

res - Received remote grid executable result.

rcvd - All previously received results. Note that if task class has GridComputeTaskNoResultCache annotation, then this list will be empty.

Returns:

Result policy that dictates how to process further upcoming job results.

Throws:

GridException - If handling a job result caused an error. This exception will be thrown out of GridComputeTaskFuture.get() method.