Python Pykafka-异步发送消息和接收确认
PyKafka有以下限制: 传递报告队列是线程本地的:它只为从当前线程生成的消息提供报告 我正在尝试编写一个脚本,在这个脚本中,我可以使用一个函数异步发送消息,并通过另一个函数不断接收确认 以下是功能:Python Pykafka-异步发送消息和接收确认,python,asynchronous,parallel-processing,pykafka,Python,Asynchronous,Parallel Processing,Pykafka,PyKafka有以下限制: 传递报告队列是线程本地的:它只为从当前线程生成的消息提供报告 我正在尝试编写一个脚本,在这个脚本中,我可以使用一个函数异步发送消息,并通过另一个函数不断接收确认 以下是功能: def SendRequest(producer): count=0 while True: count += 1 producer.produce('test msg', partition_ke
def SendRequest(producer):
count=0
while True:
count += 1
producer.produce('test msg', partition_key='{}'.format(count))
if count == 50000:
endtime=datetime.datetime.now()
print "EndTime : ",endtime
print "Done sending all messages.Waiting for response now"
return
def GetResponse(producer):
count_response=0
while True:
try:
msg, exc = producer.get_delivery_report(block=False)
if exc is not None:
count_response+=1
print 'Failed to deliver msg {}: {}'.format(
msg.partition_key, repr(exc))
else:
print "Count Res :",count_response
count_response+=1
except Queue.Empty:
pass
except Exception,e:
print "Unhandled exception : ",e
线程和多处理没有帮助。上述两个功能需要异步/并行运行。这里应该使用什么方法
问题:我可以在哪里异步发送消息。。。并不断收到确认
此带有asyncio.coroutine
的解决方案将满足您的需要
注意:有一些缺点强>
- 此
代码至少需要Python 3.5asyncio
- 对于每条消息,都会创建一个新的任务
类AsyncProduceReport()
:
import asyncio
from pykafka import KafkaClient
import queue, datetime
class AsyncProduceReport(object):
def __init__(self, topic):
self.client = KafkaClient(hosts='127.0.0.1:9092')
self.topic = self.client.topics[bytes(topic, encoding='utf-8')]
self.producer = self.topic.get_producer(delivery_reports=True)
self._tasks = 0
# async
@asyncio.coroutine
def produce(self, msg, id):
print("AsyncProduceReport::produce({})".format(id))
self._tasks += 1
self.producer.produce(bytes(msg, encoding='utf-8'))
# await - resume next awaiting task
result = yield from self.get_delivery_report(id)
self._tasks -= 1
# This return values are passed to self.callback(task)
return id, result
def get_delivery_report(self, id):
"""
This part of a Task, runs as long as of receiving the delivery_report
:param id: ID of Message
:return: True on Success else False
"""
print("{}".format('AsyncProduceReport::get_delivery_report({})'.format(id)))
while True:
try:
msg, exc = self.producer.get_delivery_report(block=False)
return (not exc, exc)
except queue.Empty:
# await - resume next awaiting task
yield from asyncio.sleep(1)
@staticmethod
def callback(task):
"""
Processing Task Results
:param task: Holds the Return values from self.produce(...)
:return: None
"""
try:
id, result = task.result()
print("AsyncProduceReport::callback: Msg:{} delivery_report:{}"
.format(id, result))
except Exception as e:
print(e)
def ensure_futures(self):
"""
This is the first Task
Creates a new taks for every Message
:return: None
"""
# Create 3 Tasks for this testcase
for id in range(1, 4):
# Schedule the execution of self.produce(id): wrap it in a future.
# Return a Task object.
# The task will resumed at the next await
task = asyncio.ensure_future(self.produce('test msg {} {}'
.format(id, datetime.datetime.now()), id))
# Add a Result Callback function
task.add_done_callback(self.callback)
# await - resume next awaiting task
# This sleep value could be 0 - Only for this testcase == 5
# Raising this value, will give more time for waiting tasks
yield from asyncio.sleep(5)
# print('Created task {}...'.format(_id))
# await - all tasks completed
while self._tasks > 0:
yield from asyncio.sleep(1)
用法:
Qutput:
AsyncProduceReport::produce(1)
AsyncProduceReport::get_delivery_report(1)
AsyncProduceReport::produce(2)
AsyncProduceReport::get_delivery_report(2)
AsyncProduceReport::callback: Msg:1 delivery_report:(True, None)
AsyncProduceReport::produce(3)
AsyncProduceReport::get_delivery_report(3)
AsyncProduceReport::callback: Msg:2 delivery_report:(True, None)
AsyncProduceReport::callback: Msg:3 delivery_report:(True, None)
使用Python:3.5.3-pykafka:2.7.0进行测试可能的副本实际上是不同的。在这里,我希望同时获取请求和确认。在您提到的示例中,首先发送所有请求,然后读取确认,因此它仍然是顺序的。
AsyncProduceReport::produce(1)
AsyncProduceReport::get_delivery_report(1)
AsyncProduceReport::produce(2)
AsyncProduceReport::get_delivery_report(2)
AsyncProduceReport::callback: Msg:1 delivery_report:(True, None)
AsyncProduceReport::produce(3)
AsyncProduceReport::get_delivery_report(3)
AsyncProduceReport::callback: Msg:2 delivery_report:(True, None)
AsyncProduceReport::callback: Msg:3 delivery_report:(True, None)