Sometimes SPDY/2, Sometimes SPDY/3.1?

[mevans336]

Hello Everyone,

We have been running SPDY/2 for months and months without issue and recently
upgraded to 1.5.10 for SPDY/3.1 support. However, we are having an issue
where sometimes our site reports SPDY/2 and sometimes it reports SPDY/3.1 in
Chrome's net-internals and the Chrome spdy extension. We use Nginx in
reverse proxy mode and have 4 servers blocks - 2 for HTTP which redirect to
2 for HTTPS (a production block and a dev block). Both blocks experience the
same behavior.

Here is an HTTP and HTTPS block:

#
# WWW
#
upstream www_servers {
ip_hash;
server 10.x.x.x:8080 max_fails=3 fail_timeout=30s;
server 10.x.x.x:8080 max_fails=3 fail_timeout=30s;
}

# Directives to enable "front end" SSL
# Disable weak SSLv2 and only accept SSLv3 and TLSv1

server {
        listen 10.x.x.x:80;
        server_name mysite.com;
        server_name www.mysite.com;

        location /feed {
                add_header X-Frame-Options SAMEORIGIN;
                proxy_set_header Host $host;
                proxy_set_header  X-Real-IP  $remote_addr;
                proxy_set_header X-Forwarded-For
$proxy_add_x_forwarded_for;
                proxy_next_upstream error timeout invalid_header;
#               proxy_http_version 1.1;
                proxy_pass http://www_servers;
                proxy_intercept_errors on;
#               error_page 504 @errors;
}

        location / {
                add_header X-Frame-Options SAMEORIGIN;
                proxy_set_header Host $host;
                proxy_set_header  X-Real-IP  $remote_addr;
                proxy_next_upstream error timeout invalid_header;
                proxy_intercept_errors on;
#                error_page 504 @errors;
                rewrite ^ https://$server_name$request_uri permanent;
        }
}

server {
        listen 10.x.x.x:443 default_server spdy ssl;
        ssl on;
        ssl_certificate         /path/to/my/ssl.crt;
        ssl_certificate_key     /path/to/my/ssl/ssl.key;
        ssl_protocols           TLSv1.2 TLSv1.1 TLSv1 SSLv3;
        ssl_ciphers            
ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-RC4-SHA:ECDHE-RSA-RC4-SHA:ECDH-ECDSA-RC4-SHA:ECDH-RSA-RC4-SHA:ECDHE-RSA-AES256-SHA:DHE-RSA-AES256-SHA:DHE-RSA-AES128-SHA:RC4-SHA;
        ssl_prefer_server_ciphers on;
        server_name mysite.com;
        server_name www.mysite.com;

        location / {
                add_header X-Frame-Options SAMEORIGIN;
                proxy_set_header Host $host;
                proxy_set_header  X-Real-IP  $remote_addr;
                proxy_set_header X-Forwarded-For
$proxy_add_x_forwarded_for;
                proxy_next_upstream error timeout invalid_header;
                proxy_intercept_errors on;
#               error_page 504 @errors;
#               proxy_http_version 1.1;
                proxy_pass http://www_servers;
        }

}

Can anyone provide any guidance on why this may be happening?

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,247412,247412#msg-247412