org.apache.drill.yarn.appMaster

Class TaskState

java.lang.Object

org.apache.drill.yarn.appMaster.TaskState

Direct Known Subclasses:

TaskState.EndingState, TaskState.KillingState

public abstract class TaskState
extends Object

Represents the behaviors associated with each state in the lifecycle of a task.

Startup process:

START --> REQUESTING

New task sends a container request to YARN.

REQUESTING --> LAUNCHING

Container received from YARN, launching the tasks's process.

LAUNCHING --> RUNNING

Task launched and needs no start Ack.

LAUNCHING --> WAIT_START_ACK

Task launched and needs a start Ack.

WAIT_START_ACK --> RUNNING

Start Ack received.

Shutdown process:

RUNNING --> WAIT_END_ACK | END

The resource manager reported task completion.

RUNNING --> ENDING

Request sent to the task for a graceful shutdown.

RUNNING --> KILLING

Request sent to the node manager to forcibly kill the task.

ENDING --> WAIT_END_ACK | END

The task gracefully exited as reported by the resource manager.

ENDING --> KILLING

The wait for graceful exit timed out, a forced kill message sent to the node manager.

KILLING --> WAIT_END_ACK | END

The task exited as reported by the resource manager.

END_ACK --> END

The end-ack is received or the wait timed out.

This is a do-it-yourself enum. Java enums values are instances of a single class. In this version, each enum value is the sole instance of a separate class, allowing each state to have its own behavior.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	TaskState.EndingState Task for which a termination request has been sent to the Drill-bit, but confirmation has not yet been received from the Node Manager.
static class	TaskState.KillingState Task for which a forced termination request has been sent to the Node Manager, but a stop message has not yet been received.

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	cancellable
static TaskState	END
static TaskState	ENDING
protected boolean	hasContainer
static TaskState	KILLING
protected String	label
static TaskState	LAUNCHING
protected TaskLifecycleListener.Event	lifeCycleEvent
static TaskState	REQUESTING
static TaskState	RUNNING
static TaskState	START
static TaskState	WAIT_END_ACK
static TaskState	WAIT_START_ACK

Constructor Summary

Constructors

Constructor and Description
TaskState(boolean hasContainer, TaskLifecycleListener.Event lcEvent, boolean cancellable)

Method Summary

Modifier and Type	Method and Description
void	cancel(EventContext context) Cluster manager wishes to cancel this task.
protected void	completed(EventContext context, org.apache.hadoop.yarn.api.records.ContainerStatus status)
void	completionAck(EventContext context) The monitoring plugin has detected that the task has confirmed that it has started shutdown.
void	containerAllocated(EventContext context, org.apache.hadoop.yarn.api.records.Container container) Resource Manager reports that the task has been allocated a container.
void	containerCompleted(EventContext context, org.apache.hadoop.yarn.api.records.ContainerStatus status) Resource Manager reports that the task has completed execution and provided the completion status.
void	containerStarted(EventContext context) Node Manager reports that the task has started execution.
void	containerStopped(EventContext context) Node Manager reports that the task has stopped execution.
protected void	endOrAck(EventContext context)
String	getLabel()
boolean	hasContainer()
boolean	isCancellable()
void	launchFailed(EventContext context, Throwable t) The launch of the container failed.
void	requestContainer(EventContext context)
void	startAck(EventContext context) The monitoring plugin has detected that the task has confirmed that it is fully started.
void	stopTaskFailed(EventContext context, Throwable t) The node manager request to stop a task failed.
protected void	taskStartFailed(EventContext context, Task.Disposition disposition) Task failed when starting.
protected void	taskTerminated(EventContext context) A running task terminated.
void	tick(EventContext context, long curTime)
String	toString()
protected void	transition(EventContext context, TaskState newState) Implement a state transition, alerting any life cycle listeners and updating the log file.

Methods inherited from class java.lang.Object

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

Field Detail

START

public static final TaskState START

REQUESTING

public static final TaskState REQUESTING

LAUNCHING

public static final TaskState LAUNCHING

WAIT_START_ACK

public static final TaskState WAIT_START_ACK

RUNNING

public static final TaskState RUNNING

ENDING

public static final TaskState ENDING

KILLING

public static final TaskState KILLING

WAIT_END_ACK

public static final TaskState WAIT_END_ACK

END

public static final TaskState END

hasContainer

protected final boolean hasContainer

lifeCycleEvent

protected final TaskLifecycleListener.Event lifeCycleEvent

label

protected final String label

cancellable

protected final boolean cancellable

Constructor Detail

TaskState

public TaskState(boolean hasContainer,
                 TaskLifecycleListener.Event lcEvent,
                 boolean cancellable)

Method Detail

endOrAck

protected void endOrAck(EventContext context)

requestContainer

public void requestContainer(EventContext context)

containerAllocated

public void containerAllocated(EventContext context,
                               org.apache.hadoop.yarn.api.records.Container container)

Resource Manager reports that the task has been allocated a container.

Parameters:

context -

container -

launchFailed

public void launchFailed(EventContext context,
                         Throwable t)

The launch of the container failed.

Parameters:

context -

t -

containerStarted

public void containerStarted(EventContext context)

Node Manager reports that the task has started execution.

Parameters:

context -

startAck

public void startAck(EventContext context)

The monitoring plugin has detected that the task has confirmed that it is fully started.

stopTaskFailed

public void stopTaskFailed(EventContext context,
                           Throwable t)

The node manager request to stop a task failed.

Parameters:

context -

t -

completionAck

public void completionAck(EventContext context)

The monitoring plugin has detected that the task has confirmed that it has started shutdown.

containerStopped

public void containerStopped(EventContext context)

Node Manager reports that the task has stopped execution. We don't yet know if this was a success or failure.

Parameters:

context -

containerCompleted

public void containerCompleted(EventContext context,
                               org.apache.hadoop.yarn.api.records.ContainerStatus status)

Resource Manager reports that the task has completed execution and provided the completion status.

Parameters:

context -

status -

cancel

public void cancel(EventContext context)

Cluster manager wishes to cancel this task.

Parameters:

context -

tick

public void tick(EventContext context,
                 long curTime)

transition

protected void transition(EventContext context,
                          TaskState newState)

Implement a state transition, alerting any life cycle listeners and updating the log file. Marks the start time of the new state in support of states that implement a timeout.

Parameters:

context -

newState -

taskStartFailed

protected void taskStartFailed(EventContext context,
                               Task.Disposition disposition)

Task failed when starting. No container has been allocated. The task will go from:
* --> END

If the run failed, and the task can be retried, it may then move from
END --> STARTING

Parameters:

context -

disposition -

taskTerminated

protected void taskTerminated(EventContext context)

A running task terminated. It may have succeeded or failed, this method will determine which.

Every task goes from:
* --> END

If the run failed, and the task can be retried, it may then move from
END --> STARTING

Parameters:

context -

completed

protected void completed(EventContext context,
                         org.apache.hadoop.yarn.api.records.ContainerStatus status)

toString

public String toString()

Overrides:

toString in class Object

hasContainer

public boolean hasContainer()

getLabel

public String getLabel()

isCancellable

public boolean isCancellable()