Requests to restlet server behind reverse proxy never complete

Question

I have a very strange problem with a Java Restlet server behind a reverse proxy.

I am using nginx to redirect an URL to a Restlet server on port 8182. The server is configured like this:

server {
    listen       8080;
    server_name  localhost;

    location / {

        proxy_set_header  X-Real-IP  $remote_addr;
        proxy_set_header  X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header  Host $http_host;
        proxy_redirect  off;

        allow all;
        root   C:/Users/Cyrille/www;
        index  index.html index.htm;
    }


    location /proxy/ping {
            proxy_pass http://localhost:8182/ping;
    }
}

When I open a browser or use wget to access http://localhost:8080/proxy/ping, the request is proxied to Restlet. It answers with simply "pong", and its log displays:

Oct 29, 2013 11:45:04 AM org.restlet.engine.log.LogFilter afterHandle
INFO: 2013-10-29    11:45:04    127.0.0.1   -   -   8182    GET /ping   -   200 4   -   6   http://localhost:8182   Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/30.0.1599.101 Safari/537.36   -

The problem is that the browser doesn't seem to ever receive the response. It just times out after a few minutes with an error 504: Gateway Time-out. If I access directly http://localhost:8182/ping, the request completes immediately.

When can the request be blocked in? I have disabled any firewall or anti-virus. I have swapped nginx with Apache and I obtain exactly the same behaviour. I am on Windows 8.

Answer 1

It turned out that it is a bug in Restlet: when the HTTP header contains "Connection:Close", the server will not send a response.

I made Nginx not send this header with the following modification and it worked.

location /proxy/ping {
        proxy_pass http://localhost:8182/ping;
        proxy_set_header Connection "";
}

Here is the link to the (still not fixed 3 years after it has been opened) Restlet bug: http://restlet.tigris.org/issues/show_bug.cgi?id=1191