In our setup we have a client that makes some web services calls to the back end with nginx as a proxy in between.

Most of the time it is successful 99% but 1% calls are dropped and the client reports the error. On retry the operation goes through fine, no other change is requried.

The client is on a hosted environment, so getting detailed logs from client is bit hard.

(Client Error) --- Error: unable to send request to : https://proxt.nginx.host.url. Server response: System.HttpResponse[Status=null, StatusCode=-1]

Nginx captures the below in the default server error log. Interestingly no access / error log is written for the virtual host that is suppose to handle the request.

2012/06/26 20:22:55 [debug] 32536#0: *305 http check ssl handshake
2012/06/26 20:22:55 [debug] 32536#0: *305 https ssl handshake: 0x16
2012/06/26 20:22:55 [debug] 32536#0: *305 http process request line
2012/06/26 20:22:55 [debug] 32536#0: *305 http process request line
2012/06/26 20:22:55 [info] 32536#0: *305 client sent invalid method while reading client request line, client: 96.43.x.x, server: , request: "User-Agent: Java/1.6.0_21"
2012/06/26 20:22:55 [debug] 32536#0: *305 http finalize request: 400, "?" a:1, c:1
2012/06/26 20:22:55 [debug] 32536#0: *305 http special response: 400, "?"
2012/06/26 20:22:55 [debug] 32536#0: *305 http set discard body
2012/06/26 20:22:55 [debug] 32536#0: *305 headers more header filter, uri ""
2012/06/26 20:22:55 [debug] 32536#0: *305 http output filter "?"
2012/06/26 20:22:55 [debug] 32536#0: *305 http copy filter: "?"
2012/06/26 20:22:55 [debug] 32536#0: *305 http postpone filter "?" 000000001C39D958
2012/06/26 20:22:55 [debug] 32536#0: *305 http write filter: l:1 f:0 s:166
2012/06/26 20:22:55 [debug] 32536#0: *305 http write filter limit 0
2012/06/26 20:22:55 [debug] 32536#0: *305 http write filter 0000000000000000
2012/06/26 20:22:55 [debug] 32536#0: *305 http copy filter: 0 "?"
2012/06/26 20:22:55 [debug] 32536#0: *305 http finalize request: 0, "?" a:1, c:1
2012/06/26 20:22:55 [debug] 32536#0: *305 http lingering close handler
2012/06/26 20:22:55 [debug] 32536#0: *305 lingering read: 0
2012/06/26 20:22:55 [debug] 32536#0: *305 http request count:1 blk:0
2012/06/26 20:22:55 [debug] 32536#0: *305 http close request
2012/06/26 20:22:55 [debug] 32536#0: *305 http log handler
2012/06/26 20:22:55 [debug] 32536#0: *305 close http connection: 10

Any pointers?