Question

我正在为连接在端口9000上的redis客户端（使用redis-py）编写一个redis服务器。

我现在编写了一个简单的测试代码，以检查服务器是否正在接收客户端的命令。我的代码如下：

client.py

import redis

r = redis.Redis(
    host="127.0.0.1",
    port=9000
)

v = r.set('foo', 1)
print(v)

v = r.set('bar', '1')

server.py

import asyncio

HOST = "127.0.0.1"
PORT = 15000


async def exo_redis(reader, writer):

    try:
        while True:
            data = await reader.readuntil(b'\r\n')
            # data = await reader.read(1024)
            if not data:
                break
            print("Data: ", data)
            response = "+OK\r\n"
            writer.write(response.encode())
            await writer.drain()

        writer.close()

    except asyncio.streams.IncompleteReadError:
        pass


def start_server():
    loop = asyncio.get_event_loop()
    coro = asyncio.start_server(exo_redis, HOST, PORT)
    server = loop.run_until_complete(coro)
    print("Serving on ", HOST, "port: ", PORT)
    try:
        loop.run_forever()
    except KeyboardInterrupt:
        print("\nShutting Down Server...\n")
    finally:
        server.close()
        loop.run_until_complete(server.wait_closed())
        loop.close()


if __name__ == '__main__':
    start_server()

运行此命令后，出现以下异常：

Data:  b'*3\r\n'
Data:  b'$3\r\n'
Data:  b'SET\r\n'
Data:  b'$3\r\n'
Data:  b'foo\r\n'
Task exception was never retrieved
future: <Task finished coro=<exo_redis() done, defined at app.py:13> exception=ConnectionResetError('Connection lost')>
Traceback (most recent call last):
  File "app.py", line 23, in exo_redis
    await writer.drain()
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/asyncio/streams.py", line 348, in drain
    await self._protocol._drain_helper()
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/asyncio/streams.py", line 202, in _drain_helper
    raise ConnectionResetError('Connection lost')
ConnectionResetError: Connection lost
Data:  b'*3\r\n'
Data:  b'$3\r\n'
Data:  b'SET\r\n'
Data:  b'$3\r\n'
Data:  b'bar\r\n'
Data:  b'$1\r\n'
Data:  b'1\r\n'

由于某种原因，从客户端发送的第一个命令会引发异常，而第二个命令则不会。

如果我使用reader.read（1024）（在代码中注释），则会得到以下输出：

Data:  b'*3\r\n$3\r\nSET\r\n$3\r\nfoo\r\n$1\r\n1\r\n'
Data:  b'*3\r\n$3\r\nSET\r\n$3\r\nbar\r\n$1\r\n1\r\n'

这有时可行，并且没有抛出异常，但是在其他时候，我收到了此异常，而命令没有被完全读取。关于如何解决这个问题的任何想法，我可以确保在服务器端收到整个命令？

ConnectionResetError（'连接丢失'）python asyncio服务器

0 个答案: