我遇到了wordpress网站及其缓存模块Varnish 4.0的问题
我可以达到大约90％的命中率，但它仍然会在后端重载我的数据库。
调查Varnish的问题似乎有些对象即将到期。 我已经取消了网站能够通过的所有cookie（管理员除外），我还检查了后端的随机URL和少量文件格式，他们似乎都没有发送缓存控制头。
我的bresp.ttl设置为30分钟。
然而，当我重新启动varnish守护程序并观察varnishstat时，计数器MAIN.n_expired会在不到一分钟的时间内开始增长。
我知道我必须做一些通行证才能不缓存管理页面和搜索结果，但是我认为过期的东西是不同的，我无法找到工具，或者一个能显示过期对象的咒语以及它们到期的原因。
编辑： 根据要求发布VCL文件：
vcl 4.0;
# Default backend definition. Set this to point to your content server.
backend default {
.host = "127.0.0.1";
.port = "8085";
.connect_timeout = 60s;
.first_byte_timeout = 60s;
.between_bytes_timeout = 60s;
.max_connections = 24000;
}
# Only allow purging from specific IPs
acl purge {
"localhost";
"127.0.0.1";
"10.0.0.113";
}
# This function is used when a request is send by a HTTP client (Browser)
sub vcl_recv {
# Normalize the header, remove the port (in case you're testing this on various TCP ports)
set req.http.Host = regsub(req.http.Host, ":[0-9]+", "");
# Allow purging from ACL
if (req.method == "PURGE") {
# If not allowed then a error 405 is returned
if (!client.ip ~ purge) {
return(synth(405, "This IP is not allowed to send PURGE requests."));
}
# If allowed, do a cache_lookup -> vlc_hit() or vlc_miss()
return (purge);
}
# Post requests will not be cached
if (req.http.Authorization || req.method == "POST") {
return (pass);
}
# --- Wordpress specific configuration
# Did not cache the RSS feed
if (req.url ~ "/feed") {
return (pass);
}
# Blitz hack
if (req.url ~ "/mu-.*") {
return (pass);
}
# Did not cache the admin and login pages
if (req.url ~ "/wp-(login|admin)") {
return (pass);
}
# pass wp-admin cookies
if (req.http.cookie) {
if (req.http.cookie ~ "(wordpress_|wp-settings-)") {
return(pass);
} else {
unset req.http.cookie;
}
}
if ( !(req.url ~ "^/wp-admin") ) {
unset req.http.Cookie;
}
# Remove has_js and CloudFlare/Google Analytics __* cookies and statcounter is_unique
set req.http.Cookie = regsuball(req.http.Cookie, "(^|;\s*)(_[_a-z]+|has_js|is_unique)=[^;]*", "");
# Remove a ";" prefix, if present.
set req.http.Cookie = regsub(req.http.Cookie, "^;\s*", "");
# Remove any Google Analytics based cookies
set req.http.Cookie = regsuball(req.http.Cookie, "__utm.=[^;]+(; )?", "");
set req.http.Cookie = regsuball(req.http.Cookie, "_ga=[^;]+(; )?", "");
set req.http.Cookie = regsuball(req.http.Cookie, "_gat=[^;]+(; )?", "");
set req.http.Cookie = regsuball(req.http.Cookie, "utmctr=[^;]+(; )?", "");
set req.http.Cookie = regsuball(req.http.Cookie, "utmcmd.=[^;]+(; )?", "");
set req.http.Cookie = regsuball(req.http.Cookie, "utmccn.=[^;]+(; )?", "");
set req.http.Cookie = regsuball(req.http.Cookie, "_ym_uid=[^;]+(; )?", "");
set req.http.Cookie = regsuball(req.http.Cookie, "__gfp_64b=[^;]+(; )?", "");
set req.http.Cookie = regsuball(req.http.Cookie, "_ym_isad=[^;]+(; )?", "");
set req.http.Cookie = regsuball(req.http.Cookie, "_ym_visorc.=[^;]+(; )?", "");
set req.http.Cookie = regsuball(req.http.Cookie, "_ym.=[^;]+(; )?", "");
set req.http.Cookie = regsuball(req.http.Cookie, "_gat.=[^;]+(; )?", "");
set req.http.Cookie = regsuball(req.http.Cookie, "(^|;\s*)(__[a-z]+|has_js)=[^;]*", "");
set req.http.Cookie = regsuball(req.http.Cookie, "(^|;\s*)(_pk_(ses|id)[\.a-z0-9]*)=[^;]*", "");
# Remove the Quant Capital cookies (added by some plugin, all __qca)
set req.http.Cookie = regsuball(req.http.Cookie, "__qc.=[^;]+(; )?", "");
# Remove the wp-settings-1 cookie
set req.http.Cookie = regsuball(req.http.Cookie, "wp-settings-1=[^;]+(; )?", "");
# Remove the wp-settings-time-1 cookie
set req.http.Cookie = regsuball(req.http.Cookie, "wp-settings-time-1=[^;]+(; )?", "");
# Remove the wp test cookie
set req.http.Cookie = regsuball(req.http.Cookie, "wordpress_test_cookie=[^;]+(; )?", "");
# Are there cookies left with only spaces or that are empty?
if (req.http.cookie ~ "^ *$") {
unset req.http.cookie;
}
# Cache the following files extensions
if (req.url ~ "\.(gif|jpg|jpeg|swf|ttf|css|js|flv|mp3|mp4|pdf|ico|png)") {
unset req.http.cookie;
}
# Set X-Forwarded-For header for logging in nginx
unset req.http.X-Forwarded-For;
set req.http.X-Forwarded-For = client.ip;
# Normalize Accept-Encoding header and compression
# https://www.varnish-cache.org/docs/3.0/tutorial/vary.html
if (req.http.Accept-Encoding) {
# Do no compress compressed files...
if (req.url ~ "\.(jpg|png|gif|gz|tgz|bz2|tbz|mp3|ogg)$") {
unset req.http.Accept-Encoding;
} elsif (req.http.Accept-Encoding ~ "gzip") {
set req.http.Accept-Encoding = "gzip";
} elsif (req.http.Accept-Encoding ~ "deflate") {
set req.http.Accept-Encoding = "deflate";
} else {
unset req.http.Accept-Encoding;
}
}
# Check the cookies for wordpress-specific items
if (req.http.Cookie ~ "wordpress_" || req.http.Cookie ~ "comment_") {
return (pass);
}
if (!req.http.cookie) {
unset req.http.cookie;
}
# --- End of Wordpress specific configuration
# Did not cache HTTP authentication and HTTP Cookie
if (req.http.Authorization || req.http.Cookie) {
# Not cacheable by default
return (pass);
}
# Cache all others requests
return (hash);
}
sub vcl_pipe {
return (pipe);
}
sub vcl_pass {
return (fetch);
}
# The data on which the hashing will take place
sub vcl_hash {
hash_data(req.url);
if (req.http.host) {
hash_data(req.http.host);
} else {
hash_data(server.ip);
}
# If the client supports compression, keep that in a different cache
if (req.http.Accept-Encoding) {
hash_data(req.http.Accept-Encoding);
}
return (lookup);
}
# This function is used when a request is sent by our backend (Nginx server)
sub vcl_backend_response {
# Remove some headers we never want to see
unset beresp.http.Server;
unset beresp.http.X-Powered-By;
# unset beresp.age;
# Enable gzip support
if (beresp.http.content-type ~"(text|javascript|application/x-font-woff)") {
set beresp.do_gzip = true;
}
# For static content strip all backend cookies
if (bereq.url ~ "\.(css|js|png|gif|jp(e?)g)|swf|ico") {
unset beresp.http.cookie;
}
# Only allow cookies to be set if we're in admin area
if (beresp.http.Set-Cookie && bereq.url !~ "^/wp-(login|admin)") {
unset beresp.http.Set-Cookie;
}
# don't cache response to posted requests or those with basic auth
if ( bereq.method == "POST" || bereq.http.Authorization ) {
set beresp.uncacheable = true;
set beresp.ttl = 10s;
set beresp.http.X-Cacheable = "NO:Got Session";
set beresp.http.cache-control = "max-age = 120";
return (deliver);
}
# don't cache search results
if ( bereq.url ~ "\?s=" ){
set beresp.uncacheable = true;
set beresp.ttl = 120s;
set beresp.http.X-Cacheable = "NO:Not Cacheable";
set beresp.http.cache-control = "max-age = 120";
return (deliver);
}
# long ttl for assets
if (bereq.url ~ "\.(gif|jpg|jpeg|swf|ttf|css|js|flv|mp3|mp4|pdf|ico|png)(\?.*|)$") {
set beresp.ttl = 30d;
set beresp.http.Cache-Control = "max-age = 86400";
}
# only cache status ok
if ( beresp.status != 200 ) {
set beresp.ttl = 1m;
set beresp.http.X-Cacheable = "YES";
set beresp.http.cache-control = "max-age = 120";
set beresp.http.Cache-Control = "max-age = 120";
return (deliver);
}
set beresp.ttl = 30m;
# Define the default grace period to serve cached content
set beresp.grace = 600s;
set beresp.http.X-Cacheable = "YES";
set beresp.http.cache-control = "max-age = 120";
set beresp.http.Cache-Control = "max-age = 120";
return (deliver);
}
# The routine when we deliver the HTTP request to the user
# Last chance to modify headers that are sent to the client
sub vcl_deliver {
if (obj.hits > 0) {
set resp.http.X-Cache = "cached";
} else {
set resp.http.x-Cache = "uncached";
}
# Remove some headers: Apache version & OS
unset resp.http.Server;
# Remove some heanders: Varnish
unset resp.http.Via;
unset resp.http.X-Varnish;
return (deliver);
}
sub vcl_init {
return (ok);
}
sub vcl_fini {
return (ok);
}