回调中出现Tornado IOLoop异常无芹菜工作线程

Question

我在celery worker中使用tornado.ioloop，因为我需要使用mongodb。

class WorkerBase():
    @gen.engine
    def foo(self,args,callback)
        bar = ['Python','Celery','Javascript','HTML']

        # ... process something ....

        callback(bar)

    @gen.engine
    def RunMyTask(self,args):

        result = yield gen.Task(self.foo,args=args)
        # Stop IOLoop instance
        IOLoop.instance().stop()


@task(name="MyWorker",base=WorkerBase)
def CeleryWorker(args):
    # This works because i'm adding base as WorkerBase
    CeleryWorker.RunMyTask(args)
    IOLoop.instance().start()
    return True

当我调用一个任务时，它给出一个错误，说：

[2014-10-02 12:12:11,561: ERROR/Worker-4] Exception in callback None
Traceback (most recent call last):
    File "/var/www/myapp/env/local/lib/python2.7/site-packages/tornado/ioloop.py", line 832, in start
fd_obj, handler_func = self._handlers[fd]
KeyError: 16

或

[2014-10-02 12:12:11,561: ERROR/Worker-4] Exception in callback None
Traceback (most recent call last):
    File "/var/www/myapp/env/local/lib/python2.7/site-packages/tornado/ioloop.py", line 832, in start
fd_obj, handler_func = self._handlers[fd]
KeyError: 14

这些错误是不一致的。是否有提升条件？

Answer 1

这看起来像是线程问题。我不熟悉celery的线程模型，但它看起来像是启动了多个CeleryWorker副本，每个副本都试图运行相同的单例IOLoop.instance()。如果您要像这样运行每个工作线程，那么每个工作线程都需要自己的IOLoop -看看同步tornado.httpclient.HTTPClient如何创建和运行临时IOLoop

Answer 2

看起来你的工作任务在ioloop停止之前刚刚返回并被视为已完成，所以我猜gen.engine的回调无法找到原始的stack_context。

@task(name="MyWorker"，base=WorkerBase) def CeleryWorker(args)：#这是可行的，因为我添加了WorkerBase CeleryWorker.RunMyTask(args) IOLoop.instance().start() return True

我有一些建议给你

1)删除返回

@task(name="MyWorker",base=WorkerBase)
def CeleryWorker(args):
    # This works because i'm adding base as WorkerBase
    CeleryWorker.RunMyTask(args)
    IOLoop.instance().start()

2)使用run_sync

import functools

@task(name="MyWorker",base=WorkerBase)
def CeleryWorker(args):
    # This works because i'm adding base as WorkerBase
    func = functools.partial(CeleryWorker.RunMyTask, args)
    IOLoop.instance().run_sync(func)