Caching
Contents
APC Install
OPcache improves PHP performance by storing precompiled script bytecode in shared memory, thereby removing the need for PHP to load and parse scripts on each request.
This extension is bundled with PHP 5.5.0 and later, and is » available in PECL for PHP versions 5.2, 5.3 and 5.4.
Again, I use a method that's generic across multiple platforms for consistency. Here are instructions for installing php opcache via Pecl.
Make sure APC has not been installed via the yum package management system. If it has, remove it before proceeding.
yum -y install php-pear php-devel httpd-devel pcre-devel gcc make && pecl install apc
Copy the options below into a file apache can reach. Usually ‘ /etc/php.d/apc.ini ‘.
restart or reload the webserver
/etc/init.d/httpd graceful
or
/etc/init.d/httpd restart
Verifying installation
Copy the apc.php file from ‘/usr/share/pear/apc.php’ to an executable location on your webserver and load in your web browser. You should see a pie-graph on the right, and general cache information on the left. Gotchas:
- Giving way too much Ram to the cache will slow the site down.
- Not giving enough Ram may cause strange out of memory errors that aren’t fixed by changing php.ini.
- If you set a password, make it a good one.
!! Warning !!
Centos has a package for APC. If you install this over the package it will not alert you that APC is already installed and your webserver will -Cease to function- To fix this:
- Prevent the extension from loading. -> Remove the .so from php.ini or move the apc.ini from /etc/php.d.
- Reload Apache so your pages start getting served again.
- Remove the pecl version -> 'pecl uninstall apc'
- Perform 'yum searc APC' to find the exact package name, execute -> 'yum erase <package_name>'
- Return to the above steps to install APC.
APC Reference:
http://www.if-not-true-then-false.com/2012/php-apc-configuration-and-usage-tips-and-tricks/
apc.ini example file. ‘ /etc/php.d/apc.ini ‘ ( I use these myself )
; Enable apc extension module extension = apc.so ; Options for the APC module version >= 3.1.3 ; See http://www.php.net/manual/en/apc.configuration.php apc.enabled=1 apc.shm_segments=1 apc.shm_size=128M apc.num_files_hint=2048 apc.user_entries_hint=4096 apc.ttl=86400 apc.use_request_time=1 apc.user_ttl=7200 apc.gc_ttl=3600 apc.cache_by_default=1 apc.filters apc.mmap_file_mask=/tmp/apc.XXXXXX apc.file_update_protection=2 apc.enable_cli=0 apc.max_file_size=1M apc.stat=1 apc.stat_ctime=0 apc.canonicalize=0 apc.write_lock=1 apc.report_autofilter=0 apc.rfc1867=1 apc.rfc1867_prefix =upload_ apc.rfc1867_name=APC_UPLOAD_PROGRESS apc.rfc1867_freq=0 apc.rfc1867_ttl=3600 apc.include_once_override=0 apc.lazy_classes=0 apc.lazy_functions=0 apc.coredump_unmap=0 apc.file_md5=0 ; not documented apc.preload_path
Generic Configs
Varnish
Centos 7 Install
yum install epel-release yum install varnish
Check your config file syntax.
Checking the file syntax Shamelessly copied from David Goodwin. Centos boxes also check when you issue a service reload. This command is good for checking syntax of a file you may be developing outside of the varnish config folder.
varnishd -C -f /etc/varnish/default.vcl
Filtering content by user agent
This section goes into sub vcl_recv
if (req.http.user-agent ~ "Lynx") {
error 200 "Health Check";
}
This section goes into sub vcl_error
if (obj.status == 200) {
set obj.http.Content-Type = "text/html; charset=utf-8";
synthetic {"<html><head><title>Varnish Health Status</title></head><body>Every time you check this page, God postpones the Zombie Apocalypse.<br><BR>( <i>Still waiting for my Nuclear Winter though</i>. )</body></html>"};
return(deliver);
}
Rejecting access by url
Wouldn't it be nice to restrict access to Drupal or Wordpress admin panels to a specific IP or range of Ip addresses in varnish?
In it's own section, create a new acl rule:
acl acl_allowed { # <-- Name is arbitrary. Avoid reserved words.
"1.2.3.0"/24;
"1.2.0.0"/16;
"1.0.0.0"/8;
"1.2.3.4"; # <-- Same as /32
}
The next section goes into vcl_recv:
To restrict access to the Drupal admin panel in Varnish:
if ( req.url ~ "^/user*" ||
req.url ~ "^/admin*") {
if (client.ip ~ acl_allowed) {
return(pass);
} else { error 404; }
}
To restrict access to the wordpress admin panel in Varnish:
if ( req.url ~ "^/wp-admin*") {
if (client.ip ~ acl_allowed) {
return(pass);
} else { error 404; }
}
Forward domain.tld to www.domain.tld
In vcl_recv:
if (req.http.host ~ "domain.tld" && req.http.host != "www.domain.tld") {
error 302;
}
in vcl_error:
if (obj.status == 302 && req.http.host == "domain.tld") {
set obj.http.Location = "http://www.domain.tld/" req.url;
}
Purging Singular pages from Varnish
Taken from: http://stackoverflow.com/questions/9215617/how-to-send-a-purge-request-in-varnish
sub vcl_recv {
if (req.request == "PURGE") {
if (!client.ip ~ acl_allowed) {
error 405 "Not allowed.";
}
return (lookup);
}
}
sub vcl_hit {
if (req.request == "PURGE") {
purge;
}
}
sub vcl_miss {
if (req.request == "PURGE") {
purge;
}
}
#!/usr/bin/php
<?php
$curl = curl_init("http://sandbox.domain.tld/test");
curl_setopt($curl, CURLOPT_CUSTOMREQUEST, "PURGE");
$output = curl_exec($curl);
?>
