Celery: Redis as broker leaving task meta keys

Question

I have celery app with Redis as broker.

The code consist of the following in a loop :

running = []
res = add.apply_async([1,2], queue='add')
running.append(res)

while running:
    r = running.pop()
    if r.ready():
        print r.get()
    else:
        running.insert(0,r)

everything works fine but when i redis-cli into redis and execute keys * I see bunch of celery-task-meta keys.

Why arent they cleaned up?
What are those for?

--

[EDIT]

I've read about CELERY_TASK_RESULT_EXPIRES setting.
Is it possible for the task keys in Redis to be cleaned up right after the result is read rather than wait until the expiration time?

Answer 1

From the Celery Doc:

AsyncResult.forget()
   Forget about (and possibly remove the result of) this task.

You have to first r.get() then r.forget()

But, You needn't cleaned up the keys. For,doc say that:

CELERY_TASK_RESULT_EXPIRES

Default is to expire after 1 day.