SchedulerStateImpl (Drill : 1.20.3 API)

java.lang.Object
- org.apache.drill.yarn.appMaster.SchedulerStateImpl

All Implemented Interfaces:

SchedulerState, SchedulerStateActions
```
public final class SchedulerStateImpl
extends Object
implements SchedulerState, SchedulerStateActions
```
Manages a the set of tasks associated with a scheduler. The scheduler decides which tasks to run or stop; the task group manages the life-cycle of the tasks for the given scheduler.
Schedulers, and hence their groups, define a priority. When starting, higher priority (lower priority value) groups run before lower priority groups. Similarly, when shrinking the cluster, lower priority groups shrink before higher priority groups.

Field Summary

Fields
Modifier and Type	Field and Description
`protected Map<org.apache.hadoop.yarn.api.records.ContainerId,Task>`	`activeContainers` Tracks running tasks: those that have been allocated containers and are starting, running, failed or ended.
`protected List<Task>`	`allocatingTasks` Tracks the tasks for which containers have been requested.
`protected List<Task>`	`pendingTasks` Tracks the tasks to be started, but for which no work has yet been done.

Constructor Summary

Constructors
Constructor and Description

SchedulerStateImpl(ClusterControllerImpl controller, Scheduler scheduler)

Constructors
Constructor and Description
`SchedulerStateImpl(ClusterControllerImpl controller, Scheduler scheduler)`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`adjustTasks()` Adjust the number of running tasks as needed to balance the number of running tasks with the desired number.
`void`	`cancel(Task task)`
`void`	`checkTasks(EventContext context, long curTime)`
`void`	`containerAllocated(EventContext context, org.apache.hadoop.yarn.api.records.Container container)` A container request has been granted.
`void`	`containerAllocated(Task task)` Mark that a task has become active and should be tracked by its container ID.
`void`	`containerReleased(Task task)` Mark that a task has completed: its container has expired or been revoked or the task has completed: successfully or a failure, as given by the task's disposition.
`void`	`dequeueAllocatingTask(Task task)` Remove a task from the list of those waiting for a container allocation.
`void`	`dequeuePendingRequest(Task task)` Remove a task from the queue of tasks waiting to send a container request.
`void`	`enqueueAllocatingTask(Task task)` Put a task onto the queue awaiting an allocation response from YARN.
`void`	`enqueuePendingRequest(Task task)` Put a task into the queue waiting to send a container request to YARN.
`List<Task>`	`getActiveTasks()` Returns the list of active tasks that have not yet been cancelled.
`int`	`getCancelledTaskCount()` The number of active tasks that have been cancelled, but have not yet ended.
`ClusterController`	`getController()`
`int`	`getLiveCount()`
`int`	`getMaxRetries()`
`String`	`getName()` Returns the name of the scheduler associated with this task action group.
`int`	`getRequestCount()`
`Scheduler`	`getScheduler()` Returns the scheduler associated with this task group.
`List<Task>`	`getStartingTasks()` Returns the list of tasks awaiting a container request to be sent to YARN or for which a container request has been sent to YARN, but no container allocation has yet been received.
`int`	`getStopTimeoutMs()`
`Task`	`getTask(int id)`
`int`	`getTaskCount()` The number of tasks in any active (non-ended) lifecycle state.
`boolean`	`hasTasks()` Report if this task group has any tasks in the active part of their life-cycle: pending, allocating or active.
`boolean`	`isDone()` Determine if this task group is done.
`int`	`maxCurrentRequests()`
`boolean`	`requestContainers(EventContext context, int maxRequests)` Request a container the first task that we wish to start.
`boolean`	`requestStop(Task task)` Request a graceful stop of the task.
`void`	`shutDown(EventContext context)` Shut down this task group by canceling all tasks not already cancelled.
`void`	`start(Task task)` Define a new task in this group.
`void`	`taskEnded(Task task)` Mark that a task has completed successfully or a failure, as given by the task's disposition.
`void`	`taskRetried(Task task)` Mark that a task is about to be retried.
`void`	`visitTaskModels(TaskVisitor visitor)`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - pendingTasks
```
protected List<Task> pendingTasks
```
    Tracks the tasks to be started, but for which no work has yet been done. (State == PENDING).
  - allocatingTasks
```
protected List<Task> allocatingTasks
```
    Tracks the tasks for which containers have been requested. (State == REQUESTED).
  - activeContainers
```
protected Map<org.apache.hadoop.yarn.api.records.ContainerId,Task> activeContainers
```
    Tracks running tasks: those that have been allocated containers and are starting, running, failed or ended. We use a map for this because, during these states, the task is identified by its container. (State == LAUNCHING, RUNNING or ENDING).
- Constructor Detail
  - SchedulerStateImpl
```
public SchedulerStateImpl(ClusterControllerImpl controller,
                          Scheduler scheduler)
```
- Method Detail
  - getName
```
public String getName()
```
    Description copied from interface: SchedulerStateActions
    
    Returns the name of the scheduler associated with this task action group.
    
    Specified by:
    
    getName in interface SchedulerStateActions
    
    Returns:
    
    The name of the scheduler associated with this task action group.
  - getMaxRetries
```
public int getMaxRetries()
```
  - getStopTimeoutMs
```
public int getStopTimeoutMs()
```
  - getScheduler
```
public Scheduler getScheduler()
```
    Description copied from interface: SchedulerStateActions
    
    Returns the scheduler associated with this task group.
    
    Specified by:
    
    getScheduler in interface SchedulerStateActions
    
    Returns:
    
    The scheduler associated with this task group.
  - start
```
public void start(Task task)
```
    Define a new task in this group. Adds it to the pending queue so that a container will be requested.
    
    Specified by:
    
    start in interface SchedulerState
    
    Parameters:
    
    task -
  - enqueuePendingRequest
```
public void enqueuePendingRequest(Task task)
```
    Put a task into the queue waiting to send a container request to YARN.
    
    Parameters:
    
    task -
  - maxCurrentRequests
```
public int maxCurrentRequests()
```
  - requestContainers
```
public boolean requestContainers(EventContext context,
                                 int maxRequests)
```
    Description copied from interface: SchedulerStateActions
    
    Request a container the first task that we wish to start.
    
    Specified by:
    
    requestContainers in interface SchedulerStateActions
  - dequeuePendingRequest
```
public void dequeuePendingRequest(Task task)
```
    Remove a task from the queue of tasks waiting to send a container request. The caller must put the task into the proper next state: the allocating queue or the completed task list.
    
    Parameters:
    
    task -
  - enqueueAllocatingTask
```
public void enqueueAllocatingTask(Task task)
```
    Put a task onto the queue awaiting an allocation response from YARN.
    
    Parameters:
    
    task -
  - containerAllocated
```
public void containerAllocated(EventContext context,
                               org.apache.hadoop.yarn.api.records.Container container)
```
    Description copied from interface: SchedulerStateActions
    
    A container request has been granted. Match the container up with the first task waiting for a container and launch the task.
    
    Specified by:
    
    containerAllocated in interface SchedulerStateActions
  - checkTasks
```
public void checkTasks(EventContext context,
                       long curTime)
```
    Specified by:
    
    checkTasks in interface SchedulerStateActions
  - dequeueAllocatingTask
```
public void dequeueAllocatingTask(Task task)
```
    Remove a task from the list of those waiting for a container allocation. The allocation may be done, or cancelled. The caller is responsible for moving the task to the next collection.
    
    Parameters:
    
    task -
  - containerAllocated
```
public void containerAllocated(Task task)
```
    Mark that a task has become active and should be tracked by its container ID. Prior to this, the task is not associated with a container.
    
    Parameters:
    
    task -
  - containerReleased
```
public void containerReleased(Task task)
```
    Mark that a task has completed: its container has expired or been revoked or the task has completed: successfully or a failure, as given by the task's disposition. The task can no longer be tracked by its container ID. If this is the last active task for this group, mark the group itself as completed.
    
    Parameters:
    
    task -
  - taskEnded
```
public void taskEnded(Task task)
```
    Mark that a task has completed successfully or a failure, as given by the task's disposition. If this is the last active task for this group, mark the group itself as completed.
    
    Parameters:
    
    task -
  - taskRetried
```
public void taskRetried(Task task)
```
    Mark that a task is about to be retried. Task still retains its state from the current try.
    
    Parameters:
    
    task -
  - shutDown
```
public void shutDown(EventContext context)
```
    Description copied from interface: SchedulerStateActions
    
    Shut down this task group by canceling all tasks not already cancelled.
    
    Specified by:
    
    shutDown in interface SchedulerStateActions
  - hasTasks
```
public boolean hasTasks()
```
    Report if this task group has any tasks in the active part of their life-cycle: pending, allocating or active.
    
    Returns:
  - isDone
```
public boolean isDone()
```
    Description copied from interface: SchedulerStateActions
    
    Determine if this task group is done. It is done when there are no active tasks and the controller itself is shutting down. This latter check differentiates the start state (when no tasks are active) from the end state. The AM will not shut down until all task groups are done.
    
    Specified by:
    
    isDone in interface SchedulerStateActions
    
    Returns:
    
    True if this task group is done. False otherwise.
  - adjustTasks
```
public void adjustTasks()
```
    Description copied from interface: SchedulerStateActions
    
    Adjust the number of running tasks as needed to balance the number of running tasks with the desired number. May result in no change it the cluster is already in balance (or is in the process of achieving balance.)
    
    Specified by:
    
    adjustTasks in interface SchedulerStateActions
  - requestStop
```
public boolean requestStop(Task task)
```
    Request a graceful stop of the task. Delegates to the task manager to do the actual work.
    
    Returns:
    
    true if the graceful stop request was sent, false if not, or if this task type has no graceful stop
  - getTaskCount
```
public int getTaskCount()
```
    Description copied from interface: SchedulerState
    
    The number of tasks in any active (non-ended) lifecycle state.
    
    Specified by:
    
    getTaskCount in interface SchedulerState
    
    Specified by:
    
    getTaskCount in interface SchedulerStateActions
    
    Returns:
    
    The number of tasks in any active (non-ended) lifecycle state.
  - getCancelledTaskCount
```
public int getCancelledTaskCount()
```
    Description copied from interface: SchedulerState
    
    The number of active tasks that have been cancelled, but have not yet ended.
    
    Specified by:
    
    getCancelledTaskCount in interface SchedulerState
  - getStartingTasks
```
public List<Task> getStartingTasks()
```
    Description copied from interface: SchedulerState
    
    Returns the list of tasks awaiting a container request to be sent to YARN or for which a container request has been sent to YARN, but no container allocation has yet been received. Such tasks are simple to cancel. The list does not contain any tasks in this state which have previously been cancelled.
    
    Specified by:
    
    getStartingTasks in interface SchedulerState
    
    Returns:
    
    The list of tasks awaiting a container request to be sent to YARN or for which a container request has been sent to YARN, but no container allocation has yet been received.
  - getActiveTasks
```
public List<Task> getActiveTasks()
```
    Description copied from interface: SchedulerState
    
    Returns the list of active tasks that have not yet been cancelled. Active tasks are any task for which a container has been assigned, but has not yet received a RM container completion event.
    
    Specified by:
    
    getActiveTasks in interface SchedulerState
    
    Returns:
    
    The list of active tasks that have not yet been cancelled.
  - cancel
```
public void cancel(Task task)
```
    Specified by:
    
    cancel in interface SchedulerState
    
    Specified by:
    
    cancel in interface SchedulerStateActions
  - getLiveCount
```
public int getLiveCount()
```
    Specified by:
    
    getLiveCount in interface SchedulerStateActions
  - visitTaskModels
```
public void visitTaskModels(TaskVisitor visitor)
```
    Specified by:
    
    visitTaskModels in interface SchedulerStateActions
  - getTask
```
public Task getTask(int id)
```
    Specified by:
    
    getTask in interface SchedulerStateActions
  - getRequestCount
```
public int getRequestCount()
```
    Specified by:
    
    getRequestCount in interface SchedulerStateActions
  - getController
```
public ClusterController getController()
```
    Specified by:
    
    getController in interface SchedulerState

Class SchedulerStateImpl

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

pendingTasks

allocatingTasks

activeContainers

Constructor Detail

SchedulerStateImpl

Method Detail

getName

getMaxRetries

getStopTimeoutMs

getScheduler

start

enqueuePendingRequest

maxCurrentRequests

requestContainers

dequeuePendingRequest

enqueueAllocatingTask

containerAllocated

checkTasks

dequeueAllocatingTask

containerAllocated

containerReleased

taskEnded

taskRetried

shutDown

hasTasks

isDone

adjustTasks

requestStop

getTaskCount

getCancelledTaskCount

getStartingTasks

getActiveTasks

cancel

getLiveCount

visitTaskModels

getTask

getRequestCount

getController