我的设置：
卷曲 - ＆gt; AWS ELB - ＆gt; Nginx - ＆gt;的NodeJS
当请求数量高时，我面临这个问题。
Nginx访问日志
xx.xx.xx.xx - - [30/Oct/2014:13:23:40 +0000] "POST /some/calls/object HTTP/1.1" 499 0 "-" "curl/7.27.0"
xx.xx.xx.xx - - [30/Oct/2014:13:23:40 +0000] "POST /some/calls/object HTTP/1.1" 499 0 "-" "curl/7.27.0"
Nginx错误日志
2014/10/30 13:23:40 [info] 11181#0: *17811 client xx.xx.xx.xx closed keepalive connection
2014/10/30 13:23:40 [info] 11181#0: *17631 epoll_wait() reported that client prematurely closed connection, so upstream connection is closed too while sending request to upstream, client: xx.xx.xx.xx, server: example.com, request: "POST /some/calls/objects HTTP/1.1", upstream: "http://xx.xx.xx.xx:xx/some/calls/object", host: "example.com"
NodeJS记录
2014-10-30T13:23:40.074Z : info : req.method GET
2014-10-30T13:23:40.074Z : info : req.url /some/calls/objects
2014-10-30T13:23:40.074Z : info : error { message: 'Request Timed Out!' }
2014-10-30T13:23:40.075Z : info : req.method GET
2014-10-30T13:23:40.075Z : info : req.url /some/calls/objects
2014-10-30T13:23:40.075Z : info : error { message: 'Request Timed Out!' }
2014-10-30T13:23:40.075Z : info : error.stack undefined
2014-10-30T13:23:40.076Z : info : error.stack undefined
问题
根据this link 499意味着客户端关闭了连接，但我的问题是，在这种情况下谁是客户端，ELB是关闭连接还是curl或nodejs？
我还观察到nodejs响应调用需要60多秒，如果nodejs遇到Timed out问题，那么它会一次又一次地发生。