【Airflow】CeleryExecutor+RabbitMQ+HAProxy做好分布式后，启动调度出现的问题
如题，笔者按照上百篇（有点夸张，50多篇吧）文章，终于在踩过了无数坑后，
搭建出了三worker节点的、CeleryExecutor+RabbitMQ+HAProxy的分布式Airflow集群（鬼知道我经历了什么）。
然后，就在我准备举杯庆祝的时候——
启动worker成功，启动webserver成功，启动scheduler后，总是报类似如下错误，
Traceback (most recent call last):
File "/home/yurii/Tools/anaconda3/bin/airflow", line 28, in args.func(args)
File"/home/yurii/Tools/anaconda3/lib/python3.6/site-packages/airflow/bin/cli.py", line 839, in scheduler job.run()
File "/home/yurii/Tools/anaconda3/lib/python3.6/site-packages/airflow/jobs.py", line 200, in run self._execute()
File "/home/yurii/Tools/anaconda3/lib/python3.6/site-packages/airflow/jobs.py", line 1309, in _execute self._execute_helper(processor_manager)
File "/home/yurii/Tools/anaconda3/lib/python3.6/site-packages/airflow/jobs.py", line 1441, in _execute_helper self.executor.heartbeat()
File "/home/yurii/Tools/anaconda3/lib/python3.6/site-packages/airflow/executors/base_executor.py", line 124, in heartbeat self.execute_async(key, command=command, queue=queue)
File "/home/yurii/Tools/anaconda3/lib/python3.6/site-packages/airflow/executors/celery_executor.py", line 80, in execute_async args=[command], queue=queue)
File "/home/yurii/Tools/anaconda3/lib/python3.6/site-packages/celery/app/task.py", line 573, in apply_async **dict(self._get_exec_options(), **options)
File "/home/yurii/Tools/anaconda3/lib/python3.6/site-packages/celery/app/base.py", line 354, in send_task reply_to=reply_to or self.oid, **options
File "/home/yurii/Tools/anaconda3/lib/python3.6/site-packages/celery/app/amqp.py", line 310, in publish_task **kwargs
File "/home/yurii/Tools/anaconda3/lib/python3.6/site-packages/kombu/messaging.py", line 172, in publish routing_key, mandatory, immediate, exchange, declare)
File "/home/yurii/Tools/anaconda3/lib/python3.6/site-packages/kombu/connection.py", line 449, in _ensured return fun(*args, **kwargs)
File "/home/yurii/Tools/anaconda3/lib/python3.6/site-packages/kombu/messaging.py", line 188, in _publish mandatory=mandatory, immediate=immediate,
File "/home/yurii/Tools/anaconda3/lib/python3.6/site-packages/librabbitmq/init.py", line 122, in basic_publish mandatory or False, immediate or False,
TypeError: an integer is required (got type NoneType)这个坑还没等我放下酒杯就唰的一下，掉进去了，爬了好久。
搜遍了所有中文文章，基本上大同小异，没有关于深入问题的解决。忽然间想起了StackOverflow,问题终于得到了解决。
解决方法大致如下：
（如果你其他设置方面都没问题，比如，dags写的完全正确，其他配置也完全正确）：
Airflow 默认使用了librabbitmq 库作为 RabbitMQ Broker，而RabbitMQ 核心团队是不推荐使用这种方法，
言外之意就是出错别找我，略略略~~。
所以要卸载掉 librabbitmq，在每台Airflow服务器上运行如下命令：
pip uninstall librabbitmq并保证每台Airflow服务器安装了 Python库 amqp，命令如下：
pip install amqp至此，问题解决。
StackOverflow原文地址[点我]
经验教训，对于发源于国外的技术，为了少走弯路，求助于国外论坛是明智的选择。
放出一些图片，表示我在认真做这件事：
Airflow测试demo：
scheduler 正常工作：
worker 启动后正常连接：
RabbitMQ 相关：
HAProxy负载均衡：
