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?