如何在 celery 任務中使用 asyncio 和 aioredis 鎖？

Question

目標：

1. 運行 asyncio 協程的可能性。
2. 更正 celery 異常和任務重試的行為。
3. 使用 aioredis 鎖的可能性。

---

那么，如何正確運行異步任務來實現目標呢？

什么是RuntimeError: await wasn't used with future （如下），我該如何解決？

---

我已經嘗試過：

1. asgiref

async_to_sync （來自 asgiref https://pypi.org/project/asgiref/ ）。

此選項可以運行 asyncio 協程，但重試功能不起作用。

2. 芹菜池異步

（ https://pypi.org/project/celery-pool-asyncio/ ）

與 asgiref 中的問題相同。 （此選項可以運行 asyncio 協程，但重試功能不起作用。）

3.編寫自己的異步到同步裝飾器

我已經嘗試創建自己的裝飾器，例如運行協程線程安全（ asyncio.run_coroutine_threadsafe ）的 async_to_sync ，但我的行為如上所述。

4.異步模塊

我還在 celery 任務中嘗試asyncio.run()或asyncio.get_event_loop().run_until_complete() （和self.retry(...) ）。 這很好用，任務運行，重試工作，但是協程執行不正確 - 在async function 內部我不能使用 aioredis。

實施說明：

• 啟動 celery 命令： celery -A celery_test.celery_app worker -l info -n worker1 -P gevent --concurrency=10 --without-gossip --without-mingle
• celery 應用程序：

transport = f"redis://localhost/9"
celery_app = Celery("worker", broker=transport, backend=transport,
                    include=['tasks'])

celery_app.conf.broker_transport_options = {
    'visibility_timeout': 60 * 60 * 24,
    'fanout_prefix': True,
    'fanout_patterns': True
}

• 實用程序：

@contextmanager
def temp_asyncio_loop():
    # asyncio.get_event_loop() automatically creates event loop only for main thread
    try:
        prev_loop = asyncio.get_event_loop()
    except RuntimeError:
        prev_loop = None
    loop = asyncio.new_event_loop()
    asyncio.set_event_loop(loop)
    try:
        yield loop
    finally:
        loop.stop()
        loop.close()
        del loop
        asyncio.set_event_loop(prev_loop)


def with_temp_asyncio_loop(f):
    @functools.wraps(f)
    def wrapper(*args, **kwargs):
        with temp_asyncio_loop() as t_loop:
            return f(*args, loop=t_loop, **kwargs)

    return wrapper


def await_(coro):
    return asyncio.get_event_loop().run_until_complete(coro)

• 任務：

@celery_app.task(bind=True, max_retries=30, default_retry_delay=0)
@with_temp_asyncio_loop
def debug(self, **kwargs):
    try:
        await_(debug_async())
    except Exception as exc:
        self.retry(exc=exc)


async def debug_async():
    async with RedisLock(f'redis_lock_{datetime.now()}'):
        pass

• redis鎖

class RedisLockException(Exception):
    pass


class RedisLock(AsyncContextManager):
    """
    Redis Lock class

    :param lock_id: string (unique key)
    :param value: dummy value
    :param expire: int (time in seconds that key will storing)
    :param expire_on_delete: int (time in seconds, set pause before deleting)

        Usage:
            try:
                with RedisLock('123_lock', 5 * 60):
                    # do something
            except RedisLockException:
    """

    def __init__(self, lock_id: str, value='1', expire: int = 4, expire_on_delete: int = None):
        self.lock_id = lock_id
        self.expire = expire
        self.value = value
        self.expire_on_delete = expire_on_delete

    async def acquire_lock(self):
        return await redis.setnx(self.lock_id, self.value)

    async def release_lock(self):
        if self.expire_on_delete is None:
            return await redis.delete(self.lock_id)
        else:
            await redis.expire(self.lock_id, self.expire_on_delete)

    async def __aenter__(self, *args, **kwargs):
        if not await self.acquire_lock():
            raise RedisLockException({
                'redis_lock': 'The process: {} still run, try again later'.format(await redis.get(self.lock_id))
            })
        await redis.expire(self.lock_id, self.expire)

    async def __aexit__(self, exc_type, exc_value, traceback):
        await self.release_lock()

在我的 windows 機器上await redis.setnx(...)塊 celery 工作人員並且它停止生成日志並且Ctrl+C不起作用。

在 docker 容器內，我收到一個錯誤。 有部分回溯：

Traceback (most recent call last):
  File "/usr/local/lib/python3.9/site-packages/aioredis/connection.py", line 854, in read_response
    response = await self._parser.read_response()
  File "/usr/local/lib/python3.9/site-packages/aioredis/connection.py", line 366, in read_response
    raise ConnectionError(SERVER_CLOSED_CONNECTION_ERROR)
aioredis.exceptions.ConnectionError: Connection closed by server.

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/local/lib/python3.9/site-packages/celery/app/trace.py", line 451, in trace_task
    R = retval = fun(*args, **kwargs)
  File "/usr/local/lib/python3.9/site-packages/celery/app/trace.py", line 734, in __protected_call__
    return self.run(*args, **kwargs)
  File "/usr/local/lib/python3.9/site-packages/celery/app/autoretry.py", line 54, in run
    ret = task.retry(exc=exc, **retry_kwargs)
  File "/usr/local/lib/python3.9/site-packages/celery/app/task.py", line 717, in retry
    raise_with_context(exc)
  File "/usr/local/lib/python3.9/site-packages/celery/app/autoretry.py", line 34, in run
    return task._orig_run(*args, **kwargs)
  File "/app/celery_tasks/tasks.py", line 69, in wrapper
    return f(*args, **kwargs) # <--- inside with_temp_asyncio_loop from utils
  ...
  File "/usr/local/lib/python3.9/contextlib.py", line 575, in enter_async_context
    result = await _cm_type.__aenter__(cm)
  File "/app/db/redis.py", line 50, in __aenter__
    if not await self.acquire_lock():
  File "/app/db/redis.py", line 41, in acquire_lock
    return await redis.setnx(self.lock_id, self.value)
  File "/usr/local/lib/python3.9/site-packages/aioredis/client.py", line 1064, in execute_command
    return await self.parse_response(conn, command_name, **options)
  File "/usr/local/lib/python3.9/site-packages/aioredis/client.py", line 1080, in parse_response
    response = await connection.read_response()
  File "/usr/local/lib/python3.9/site-packages/aioredis/connection.py", line 859, in read_response
    await self.disconnect()
  File "/usr/local/lib/python3.9/site-packages/aioredis/connection.py", line 762, in disconnect
    await self._writer.wait_closed()
  File "/usr/local/lib/python3.9/asyncio/streams.py", line 359, in wait_closed
    await self._protocol._get_close_waiter(self)
RuntimeError: await wasn't used with future

• 庫版本：

celery==5.2.1
aioredis==2.0.0

Answer 1

也許它有幫助。 https://github.com/aio-libs/aioredis-py/issues/1273

要點是：

將對get_event_loop 的所有調用替換為 get_running_loop ，這將在未來附加到不同的循環時刪除該運行時異常。