我有一个Python Tornado服务器位于nginx前端。偶尔会出现502错误,但不是每次都会出现。我查看了nginx访问日志,发现如下内容:
127.0.0.1 - - [02/Jun/2010:18:04:02 -0400] "POST /a/question/updates HTTP/1.1" 502 173 "http://localhost/tagged/python" "Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.2.3) Gecko/20100401 Firefox/3.6.3"
并且在错误日志中:
2010/06/02 18:04:02 [error] 14033#0: *1700 connect() failed (111: Connection refused)
while connecting to upstream, client: 127.0.0.1, server: _,
request: "POST /a/question/updates HTTP/1.1",
upstream: "http://127.0.0.1:8888/a/question/updates", host: "localhost", referrer: "http://localhost/tagged/python"
我不认为Tornado日志中会显示任何错误。你该如何调试这个问题?是否有什么我可以在Tornado或nginx配置中添加来帮助调试此问题?