Optimizing Your WordPress Cache Loads in Lighttpd.
If you don’t configure your wordpress virtual host properly in lighttpd, your wordpress cache will still make use of PHP.
Wouldn’t it be nice if all those cached requests were served directy from the webserver as the static files that they are, bypassing the CPU/memory load PHP can have, and use those resources for otherthings?
Install and Enable mod_magnet
For this to occur with lighttpd, you will need mod_magnet, so assuming you’re on a Ubuntu/Debian based linux distro let’s make sure we have it installed.
sudo apt-get install lighttpd-mod-magnet
Then let’s make sure it’s enabled, you can do this manually on your lighttpd.conf by adding “mod_magnet” to the list of enabled modules…
server.modules = (
"mod_fastcgi",
"mod_access",
"mod_alias",
"mod_accesslog",
"mod_compress",
"mod_rewrite",
"mod_redirect",
"mod_status",
"mod_proxy",
"mod_setenv",
"mod_magnet"
)
or you can do it the lighty way:
sudo lighty-enable-mod magnet
(this simply makes a symlink to the 10-magnet.conf file inside /etc/lighttpd/conf-enabled which lighty will check upon startup)
The cache logic script that will be executed by lighttpd
Now, on your wordpress directory, create a file called rewrite.lua and paste the following script in it:
function log(str)
-- wanna tail -f a log to see what's happening
fp = io.open("/path/to/some/lua.log","a+")
fp:write(str .. "\n")
fp:flush()
fp:close()
end
function serve_html(cached_page)
if (lighty.stat(cached_page)) then
lighty.env["physical.path"] = cached_page
return true
else
return false
end
end
function serve_gzip(cached_page)
if (lighty.stat(cached_page .. ".gz")) then
lighty.header["Content-Encoding"] = "gzip"
lighty.header["Content-Type"] = ""
lighty.env["physical.path"] = cached_page .. ".gz"
return true
else
return false
end
end
if (lighty.env["uri.scheme"] == "http") then
ext = ".html"
else
ext = "-https.html"
end
cached_page = lighty.env["physical.doc-root"] .. "/wp-content/cache/supercache/" .. lighty.request["Host"] .. lighty.env["request.orig-uri"]
cached_page = string.gsub(cached_page, "//", "/")
cached_page = string.gsub(cached_page, lighty.request["Host"] .. "/index.php", lighty.request["Host"])
attr = lighty.stat(cached_page)
if (attr) then
query_condition = not (lighty.env["uri.query"] and string.find(lighty.env["uri.query"], ".*s=.*"))
user_cookie = lighty.request["Cookie"] or "no_cookie_here"
cookie_condition = not (string.find(user_cookie, ".*comment_author.*") or (string.find(user_cookie, ".*wordpress.*") and not string.find(user_cookie,"wordpress_test_cookie")))
if (query_condition and cookie_condition) then
accept_encoding = lighty.request["Accept-Encoding"] or "no_acceptance"
if (string.find(accept_encoding, "gzip")) then
if not serve_gzip(cached_page) then
serve_html(cached_page)
end
else
serve_html(cached_page)
end
--log('cache-hit: ' .. cached_page)
end
else
--log('cache-miss: ' .. cached_page)
end
Configuring your vhost in lighttpd for WordPress redirects and direct cache serves without php.
Then on your vhost configuration in lighttpd.conf add the following towards the end.
(Fix paths if you have to)
var.wp_blog = 1
magnet.attract-physical-path-to = ( server.document-root + "/rewrite.lua" )
url.rewrite-if-not-file = (
"^/(wp-.+).*/?" => "$0",
"^/(sitemap.xml)" => "$0",
"^/(xmlrpc.php)" => "$0",
"^/(.+)/?$" => "/index.php/$1"
)
Restart your lighttpd sudo service lighttpd restart
Now watch how your PHP processes breathe a lot better and you page loads are insanely faster.
You’re welcome 🙂
