Celery任务状态仅为“ PENDING”和“ SUCCESS”。为什么任务状态中没有“ STARTED”？

我正在演示，代码很简单：

# tasks.py
import time

from celery import Celery

app = Celery('tasks',
             broker='redis://:5tgb^YHN7ujm*IK<@localhost:6379/0',
             backend='redis://:5tgb^YHN7ujm*IK<@localhost:6379/0'
             )


@app.task
def test_task(s):
    time.sleep(300)
    return s

然后开始工作

 celery -A celery_test.app  worker -n kalidog -c 2 -l debug -E

 -------------- celery@kalidog v4.3.0 (rhubarb)
---- **** ----- 
--- * ***  * -- Linux-4.9.0-8-amd64-x86_64-with-debian-9.8 2019-10-11 02:36:12
-- * - **** --- 
- ** ---------- [config]
- ** ---------- .> app:         tasks:0x7f17bf92e128
- ** ---------- .> transport:   redis://:**@localhost:6379/0
- ** ---------- .> results:     redis://:**@localhost:6379/0
- *** --- * --- .> concurrency: 2 (prefork)
-- ******* ---- .> task events: ON
--- ***** ----- 
 -------------- [queues]
                .> celery           exchange=celery(direct) key=celery          

然后安排任务：

>>>from celery_test import test_task
>>>result = test_task.apply_async((11,)) 
>>>result.status
'PENDING'
>>>result.state
'PENDING'
>>>result.state
'PENDING'
>>>result.state
'SUCCESS'

为什么任务状态中没有“开始”？我检查了redis。在任务完成之前，redis中没有当前任务的密钥，例如“ celery-task-meta-XXX”。