高并发下tornado使用asyncio循环报错

error occurs when using asycio loop in tornado under high concurrency

我在tornado项目中安装了asyncioIoloop,运行单个请求没有问题,但是当我做服务器压力测试时:

ab -n 10000 -c 4000  -p '/home/mwh/ad_tornado/for_test/task.json' -T 'application/x-www-form-urlencoded' '192.168.1.170/hwSdk/tsk/get_t_k.json'

发生错误:

[E 161216 10:32:22 base_events:1090] Exception in callback BaseAsyncIOLoop._handle_events(11, 1)
handle: <Handle BaseAsyncIOLoop._handle_events(11, 1)>
Traceback (most recent call last):
  File "/usr/local/lib/python3.4/asyncio/events.py", line 125, in _run
  File "/home/mwh/virtualenv_mwh/lib/python3.4/site-packages/tornado/platform/asyncio.py", line 114, in _handle_events
  File "/home/mwh/virtualenv_mwh/lib/python3.4/site-packages/tornado/stack_context.py", line 275, in null_wrapper
  File "/home/mwh/virtualenv_mwh/lib/python3.4/site-packages/tornado/netutil.py", line 260, in accept_handler
  File "/usr/local/lib/python3.4/socket.py", line 187, in accept
OSError: [Errno 24] Too many open files

在 tornado 中使用 asynico ioloop 会降低性能吗?

您正在尝试 运行 4000 并行请求,这意味着 4000 同时打开套接字。

但通常系统限制默认只允许打开 1024 个文件(尝试 ulimit -a)。

您可以通过 ulimit -n 4096 调用来覆盖限制。