Nginx
為什麼 SPDY 會在 Nginx 1.4.3 中破壞“Vary: Accept-Encoding”？
我已經使用 SPDY 模組從原始碼編譯了 Nginx 1.4.3。
但是，當啟用 SPDY 時，它似乎破壞了我的“Vary: Accept-Encoding”標頭。
我的 Nginx 配置：
./configure --conf-path=/etc/nginx/nginx.conf --pid-path=/var/run/nginx.pid --error-log-path=/var/log/nginx/error.log --http-proxy-temp-path=/var/cache/nginx/proxy_temp --http-fastcgi-temp-path=/var/cache/nginx/fastcgi_temp --http-uwsgi-temp-path=/var/cache/nginx/uwsgi_temp --http-scgi-temp-path=/var/cache/nginx/scgi_temp --http-log-path=/var/log/nginx/access.log --with-http_ssl_module --prefix=/usr --add-module=./nginx-sticky-module-1.1 --add-module=./headers-more-nginx-module-0.23 --with-http_spdy_module我的“nginx.conf”文件：
user nginx; worker_processes 1; error_log /var/log/nginx/error.log warn; pid /var/run/nginx.pid; events { worker_connections 1024; } http { include /etc/nginx/mime.types; default_type application/octet-stream; log_format main '$remote_addr - $remote_user [$time_local] "$request" ' '$status $body_bytes_sent "$http_referer" ' '"$http_user_agent" "$http_x_forwarded_for"'; access_log /var/log/nginx/access.log main; sendfile on; #tcp_nopush on; keepalive_timeout 65; #Compression Settings gzip on; gzip_http_version 1.0; gzip_comp_level 2; gzip_proxied any; gzip_min_length 1100; gzip_buffers 16 8k; gzip_types text/plain text/css application/x-javascript text/xml application/xml application/xml+rss text/javascript image/svg+xml; # Some version of IE 6 don't handle compression well on some mime-types, # so just disable for them gzip_disable "MSIE [1-6].(?!.*SV1)"; # Set a vary header so downstream proxies don't send cached gzipped # content to IE6 gzip_vary on; proxy_cache_path /var/www/nginx_cache levels=1:2 keys_zone=qnx-cache:10m inactive=24h max_size=1g; proxy_temp_path /var/www/nginx_cache/tmp; server_tokens off; include /etc/nginx/conf.d/*.conf; map $geo $mapping { default default; US US; DE DE; CA CA; GB GB; } geo $geo { default default; include geo.conf; } upstream default.backend { # sticky; server 192.168.0.5:8080; server 192.168.0.6:8080; server 192.168.0.7:8080; } upstream mysite.backend { sticky name=servIDTrack hash=sha1; server 192.168.0.5:8080 weight=10 max_fails=3 fail_timeout=10s; server 192.168.0.6:8080 weight=10 max_fails=3 fail_timeout=10s; server 192.168.0.7:8080 weight=10 max_fails=3 fail_timeout=10s; } server { listen 80; server_name secure.mysite.com; return 301 https://$server_name$request_uri; } server { listen 443 ssl; server_name secure.mysite.com; more_set_headers "Server: X-nginx/v1.1 [LB01]"; ssl_certificate /etc/nginx/ssl/secure_mysite_com_ssl.cert; ssl_certificate_key /etc/nginx/ssl/secure_mysite_com_ssl.key; ssl_protocols SSLv3 TLSv1 TLSv1.1 TLSv1.2; # ssl_ciphers RC4:HIGH:!aNULL:!MD5; 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:RC4-SHA; ssl_prefer_server_ciphers on; keepalive_timeout 120; ssl_session_cache builtin:1000 shared:SSL:10m; ssl_session_timeout 10m; location / { proxy_pass http://mysite.backend; 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_redirect off; proxy_http_version 1.1; add_header Strict-Transport-Security "max-age=31556926; includeSubdomains"; # Cache proxy_cache qnx-cache; proxy_cache_valid 200 301 302 120m; proxy_cache_valid 404 1m; add_header X-Cache-Status $upstream_cache_status; proxy_cache_key "$scheme$host$request_uri"; } } }啟用/禁用 SPDY 的標題結果：
url: mypage.php (SPDY enabled) HTTP/1.1 200 OK cache-control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0 content-encoding: gzip content-type: text/html; charset=utf-8 date: Wed, 20 Nov 2013 13:39:30 GMT expires: Thu, 19 Nov 1981 08:52:00 GMT pragma: no-cache server: X-nginx/v1.1 [LB01] status: 200 strict-transport-security: max-age=31556926; includeSubdomains version: HTTP/1.1 x-cache-status: MISS url: mypage.php (SPDY disabled) HTTP/1.1 200 OK Date: Wed, 20 Nov 2013 13:45:00 GMT Content-Type: text/html; charset=utf-8 Transfer-Encoding: chunked Connection: keep-alive Vary: Accept-Encoding Expires: Thu, 19 Nov 1981 08:52:00 GMT Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0 Pragma: no-cache Server: X-nginx/v1.1 [LB01] Strict-Transport-Security: max-age=31556926; includeSubdomains X-Cache-Status: MISS Content-Encoding: gzip url: mystyle.css (SPDY enabled) HTTP/1.1 200 OK date: Wed, 20 Nov 2013 12:53:49 GMT content-encoding: gzip last-modified: Mon, 18 Nov 2013 22:09:32 GMT server: X-nginx/v1.1 [LB01] x-cache-status: HIT strict-transport-security: max-age=31556926; includeSubdomains content-type: text/css status: 304 expires: Wed, 18 Dec 2013 22:42:35 GMT cache-control: max-age=2592000 version: HTTP/1.1 url: mystyle.css (SPDY disabled) HTTP/1.1 200 OK Date: Wed, 20 Nov 2013 13:45:01 GMT Content-Type: text/css Transfer-Encoding: chunked Connection: keep-alive Vary: Accept-Encoding Last-Modified: Mon, 18 Nov 2013 22:09:32 GMT Cache-Control: max-age=2592000 Expires: Wed, 18 Dec 2013 22:10:13 GMT Server: X-nginx/v1.1 [LB01] Strict-Transport-Security: max-age=31556926; includeSubdomains X-Cache-Status: HIT Content-Encoding: gzip如您所見，啟用 SPDY 後，
Vary: Accept-Encoding標題消失了。這是我
nginx.conf的配置方式的問題嗎？
SPDY（和 HTTP/2.0）要求使用者代理支持壓縮，這使得
Vary: Accept-Encoding標頭毫無用處。這就是為什麼 nginx 會刪除標頭。
它可能是也可能不是錯誤，但由於 SPDY 始終使用壓縮，並且目前沒有 SPDY 轉發代理（因為 SPDY 始終使用 TLS），所以 Vary 標頭是無用的。僅代理使用 Vary 來確定是發送壓縮內容還是未壓縮內容
基本上，如果連接系統支持 SPDY，它也支持 gzip 壓縮內容，因此無需在 Vary 標頭上浪費字節。這就是至少一些支持 SPDY 的大型網站正在做的事情。有關詳細資訊，請參閱此頁面。
從理論上講，有朝一日可能會有 SPDY 代理出現在那些擁有不支持 HTTP 壓縮的舊版瀏覽器的公司中，但我真的希望不會。即使有，如果客戶端沒有發送“Accept-Encoding：gzip”標頭，代理也可以以低成本即時解壓縮。