Question

我已经成功创建了一种使用长轮询从SQS队列中提取消息的方法，如下所示：

def dequeue_message(self, callback):
    result = self.queue.receive_messages(MaxNumberOfMessages=1)
    if len(result) != 0:
        body = result[0].body
        try:
            callback(body)
            result.delete()
        except Exception as e:
            print("message not dequeued because an error occurred"
                  "when running callback: " + str(e))

但是我找不到不终止正在运行的Python进程（或者显然等待超时）的停止轮询的方法。我该怎么办？

Answer 1

您可以简单地使用一个标志来做到这一点。假定按钮应中断轮询过程。按下按钮后即可更新标记。然后，当轮询返回一组消息时，您检查该标志，并忽略对消息的处理。不用担心，消息仍然会在队列中。参见：link

Amazon SQS在收到消息后不会自动删除消息为您服务，以防您未成功收到消息（例如，消费者可能会失败或失去连接）。删除一个消息，您必须发送一个单独的请求以确认您因为您已经成功接收并且不再需要该消息处理了。

示例代码：

# This is the flag to check for interruptions
is_interrupted = False

# This function will set the flag if an interruption is occurred
def interrupt_polling():
    is_interrupted = True


def dequeue_message(self, callback):
    result = self.queue.receive_messages(MaxNumberOfMessages=1)

    # this is the check that will bypass the Polling process
    # Handle this logic as required
    if is_interrupted:
        # assuming that this needs to be reset to False
        is_interrupted = False
        return

    if len(result) != 0:
        body = result[0].body
        try:
            callback(body)
            result.delete()
        except Exception as e:
            print("message not dequeued because an error occurred"
                  "when running callback: " + str(e))

希望这会有所帮助。

Boto3：有没有一种方法可以正常中断SQS长轮询接收消息请求？

1 个答案: