celery.contrib.abortable

Abortable Tasks.

from celery.contrib.abortable import AbortableTask
from celery.utils.log import get_task_logger

from proj.celery import app

logger = get_logger(__name__)

@app.task(bind=True, base=AbortableTask)
def long_running_task(self):
    results = []
    for i in range(100):
        # check after every 5 iterations...
        # (or alternatively, check when some timer is due)
        if not i % 5:
            if self.is_aborted():
                # respect aborted state, and terminate gracefully.
                logger.warning('Task aborted')
                return
            value = do_something_expensive(i)
            results.append(y)
    logger.info('Task complete')
    return results

import time

from proj.tasks import MyLongRunningTask

def myview(request):
    # result is of type AbortableAsyncResult
    result = long_running_task.delay()

    # abort the task after 10 seconds
    time.sleep(10)
    result.abort()

classcelery.contrib.abortable.AbortableAsyncResult(id, backend=None, task_name=None, app=None, parent=None)

Represents an abortable result.

Specifically, this gives the AsyncResult a abort() method, that sets the state of the underlying Task to ‘ABORTED’.

abort()

Set the state of the task to ABORTED.

Abortable tasks monitor their state at regular intervals and terminate execution if so.

Warning

Be aware that invoking this method does not guarantee when the task will be aborted (or even if the task will be aborted at all).

is_aborted()

Return True if the task is (being) aborted.

classcelery.contrib.abortable.AbortableTask

Task that can be aborted.

This serves as a base class for all Task’s that support aborting during execution.

All subclasses of AbortableTask must call the is_aborted() method periodically and act accordingly when the call evaluates to True.

AsyncResult(task_id)

Return the accompanying AbortableAsyncResult instance.

abstract=True

Deprecated attribute abstract here for compatibility.

is_aborted(**kwargs)

Return true if task is aborted.

Checks against the backend whether this AbortableAsyncResult is ABORTED.

Always return False in case the task_id parameter refers to a regular (non-abortable) Task.

Be aware that invoking this method will cause a hit in the backend (for example a database query), so find a good balance between calling it regularly (for responsiveness), but not too often (for performance).