Tornado POST 请求直接 599 了，经过 WireShark 抓包发现根本没有发出请求。
最后竟然发现和版本有关，4.1 下才有问题，4.2 以后就好了。
实验代码
# -*- coding: utf-8 -*-
import logging
import urllib
from tornado import gen, httpclient, ioloop
logging.basicConfig(level=logging.DEBUG,
format='%(asctime)s %(levelname)s [%(name)s:%(funcName)s#%(lineno)s] %(message)s')
LOG = logging.getLogger(__name__)
API_KEY = '5j1znBVAsnSf5xQyNQyq'
API_URL = 'http://www.pm25.in/api/querys/pm2_5.json'
DEFAULT_HTTP_PARAMS = {
'allow_nonstandard_methods': True,
'raise_error': False,
'request_timeout': 5,
'connect_timeout': 3,
}
@gen.coroutine
def test():
client = httpclient.AsyncHTTPClient()
method = 'POST'
params = [('city', 'beijing'), ('token', API_KEY)]
qs = urllib.urlencode(params)
url = API_URL + '?' + qs
LOG.debug('%s %s', method, url)
resp = yield client.fetch(url, method='POST', **DEFAULT_HTTP_PARAMS)
LOG.debug([resp.code, resp.reason, resp.headers, resp.body])
def main():
ioloop.IOLoop.current().run_sync(test)
if __name__ == '__main__':
main()
实验
Tornado 4.1：
2015-10-04 15:39:05,020 DEBUG [__main__:test#32] POST http://www.pm25.in/api/querys/pm2_5.json?city=beijing&token=5j1znBVAsnSf5xQyNQyq
2015-10-04 15:39:10,023 DEBUG [__main__:test#34] [599, 'Unknown', {}, None]
Tornado 4.2：
2015-10-04 15:39:50,204 DEBUG [__main__:test#32] POST http://www.pm25.in/api/querys/pm2_5.json?city=beijing&token=5j1znBVAsnSf5xQyNQyq
2015-10-04 15:39:50,603 DEBUG [__main__:test#34] [404, 'Not Found', {'Status': '404', 'Content-Length': '729', 'X-Powered-By': 'Phusion Passenger (mod_rails/mod_rack)', 'X-Request-Id': 'c5442b9e5f79ff1e834837f07f617572', 'Server': 'nginx', 'Connection': 'close', 'Date': 'Tue, 12 Oct 2021 07:39:50 GMT', 'X-Runtime': '0.013833', 'Content-Type': 'text/html; charset=utf-8', 'X-Rack-Cache': 'invalidate, pass'}, '<!DOCTYPE html>\n<html>\n<head>\n <title>The page you were looking for doesn\'t exist (404)</title>\n <style type="text/css">\n body { background-color: #fff; color: #666; text-align: center; font-family: arial, sans-serif; }\n div.dialog {\n width: 25em;\n padding: 0 4em;\n margin: 30em auto 0 auto;\n border: 1px solid #ccc;\n border-right-color: #999;\n border-bottom-color: #999;\n }\n h1 { font-size: 100%; color: #f00; line-height: 1.5em; }\n </style>\n</head>\n\n<body>\n <!-- This file lives in public/404.html -->\n <div class="dialog">\n <h1>The page you were looking for doesn\'t exist.</h1>\n <p>You may have mistyped the address or the page may have moved.</p>\n </div>\n</body>\n</html>\n']
结论
经过对源码的分析，发现是 4.1 版本发送请求的时候，如果没有传 body，不会调用 connection.finish，请求不会真实发出，直到超时被 Tornado 捕获。
这个问题在 2015/03/09 被修复（commit），然后并入了 Tornado 4.2。
commit cf2a54794ff5067d6d815013d6570ee10f74d5e5
Author: Ben Darnell <ben@bendarnell.com>
Date: 2015-03-08 23-08-25
simple_httpclient: finish() should be called even for body-less GET.
This matters for HTTP2 where there is an explicit end-stream marker.
diff --git a/tornado/simple_httpclient.py b/tornado/simple_httpclient.py
index beb55f23..6321a81d 100644
--- a/tornado/simple_httpclient.py
+++ b/tornado/simple_httpclient.py
@@ -375,7 +375,6 @@ class _HTTPConnection(httputil.HTTPMessageDelegate):
def _write_body(self, start_read):
if self.request.body is not None:
self.connection.write(self.request.body)
- self.connection.finish()
elif self.request.body_producer is not None:
fut = self.request.body_producer(self.connection.write)
if is_future(fut):
@@ -386,7 +385,7 @@ class _HTTPConnection(httputil.HTTPMessageDelegate):
self._read_response()
self.io_loop.add_future(fut, on_body_written)
return
- self.connection.finish()
+ self.connection.finish()
if start_read:
self._read_response()
我认为这是一个 BUG，既然有参数 allow_nonstandard_methods 允许不带 body 的 POST 请求，就应该将请求发出。
不过这个提交日志好像我说的没有关系...
定位到了问题就知道该怎么修复了，只需要传一个 body='' 就行了。
