我在我的应用程序中结合了 dropbox 和 celery,如果用户连接了 dropbox,我将允许他们存储自己的照片。
我写了一段代码,但我担心这可能会导致死循环,从而杀死系统。
我正在使用的 API 一次只允许 60 张照片,然后它会为您提供分页。
这是我的 tasks.py 文件的副本 - 这实际上工作正常,但我想检查我做的事情是否正确并且不会对系统造成太大影响。
class DropboxUsers(PeriodicTask):
run_every = timedelta(hours=4)
def run(self, **kwargs):
logger = self.get_logger(**kwargs)
logger.info("Collecting Dropbox users")
dropbox_users = UserSocialAuth.objects.filter(provider='dropbox')
for db in dropbox_users:
...
...
...
sync_images.delay(first, second, third_argument)
return True
@task(ignore_result=True)
def sync_images(token, secret, username):
"""docstring for sync_images"""
logger = sync_images.get_logger()
logger.info("Syncing images for %s" % username)
...
...
...
...
feed = api.user_recent_media(user_id='self', count=60)
images = feed[0]
pagination = feed[1]
for obj in images:
### STORE TO DROPBOX
...
...
...
response = dropbox.put_file(f, my_picture, overwrite=True)
### CLOSE DB SESSION
sess.unlink()
if pagination:
store_images.delay(first, second, third, fourth_argument)
@task(ignore_result=True)
def store_images(token, secret, username, max_id):
"""docstring for sync_images"""
logger = store_images.get_logger()
logger.info("Storing images for %s" % username)
...
...
...
...
feed = api.user_recent_media(user_id='self', count=60, max_id=max_id)
images = feed[0]
try:
pagination = feed[1]
except:
pagination = None
for obj in images:
### STORE TO DROPBOX
...
...
...
response = dropbox.put_file(f, my_picture, overwrite=True)
### CLOSE DB SESSION
sess.unlink()
if pagination:
### BASICALLY RESTART THE TASK WITH NEW ARGS
store_images.delay(first, second, third, fourth_argument)
return True
非常感谢您的专业知识。
最佳答案
我没有发现任何重大问题。我还实现了一个任务启动另一个任务的系统。
有一段时间,我在服务器重启时遇到 celery 复制任务的问题。我写了一个装饰器来包装一个使用缓存后端的任务,以确保具有相同参数的相同任务不会运行得太频繁。可能对您有用,可以防止无限循环。
from django.core.cache import cache as _djcache
from django.utils.functional import wraps
class cache_task(object):
""" Makes sure that a task is only run once over the course of a configurable
number of seconds. Useful for tasks that get queued multiple times by accident,
or on service restart, etc. Uses django's cache (memcache) to keep track."""
def __init__(self, seconds=120, minutes=0, hours=0):
self.cache_timeout_seconds = seconds + 60 * minutes + 60 * 60 * hours
def __call__(self, task):
task.unsynchronized_run = task.run
@wraps(task.unsynchronized_run)
def wrapper(*args, **kwargs):
key = sha1(str(task.__module__) + str(task.__name__) + str(args) + str(kwargs)).hexdigest()
is_cached = _djcache.get(key)
if not is_cached:
# store the cache BEFORE to cut down on race conditions caused by long tasks
if self.cache_timeout_seconds:
_djcache.set(key, True, self.cache_timeout_seconds)
task.unsynchronized_run(*args, **kwargs)
task.run = wrapper
return task
用法:
@cache_task(hours=2)
@task(ignore_result=True)
def store_images(token, secret, username, max_id):
...
关于python - 任务中的 celery 任务,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/10719456/