使用memcache对wordpress优化,提速

环境：

一个本地开发环境

一个部署在虚拟机中（ 虚拟机安装memcache缓存）,然后用这个优化的版本跟本地开发环境对比.

wordpress版本：4.9.5

php:5.6版本

1，首先在主题的functions.php文件中，加入以下监控统计代码

function performance( $visible = true ) {
    $stat = sprintf(  '%d queries in %.3f seconds, using %.2fMB memory',
        get_num_queries(),
        timer_stop( 0, 3 ),
        memory_get_peak_usage() / 1024 / 1024
    );
    // echo $visible ? $stat : "<!-- {$stat} -->" ;
    echo "<div class='container_12'><p class='grid_12 footer clearfix'>$stat</p></div>";
}

add_action( 'wp_footer', 'performance', 20 );

样式可以根据自己的主题定制，这段代码可以统计出页面有多少次数据库查询。总共花了多少秒，耗费多少内存，类似如下的样式：

16 queries in 1.306 seconds, using 12.98MB memory

2，安装memcached服务端

[root@bogon wp-content]# ps -ef | grep memcached
root      5050  3466  0 14:44 pts/1    00:00:00 grep memcached
root     29269     1  0 13:57 ?        00:00:02 /usr/local/memcached/bin/memcached -d -l 127.0.0.1 -p 11211 -u root -m 64 -c 1024 -P /var/run/memcached.pid

3，安装php memcache扩展

wget http://pecl.php.net/get/memcache-3.0.8.tgz，用phpize外挂方式安装，安装完成之后，在php.ini中启用，再重启php,确定memcache已经加载

memcache
memcache support    enabled
Version    3.0.8
Revision    $Revision: 329835 $
Directive    Local Value    Master Value
memcache.allow_failover    1    1
memcache.chunk_size    32768    32768
memcache.compress_threshold    20000    20000
memcache.default_port    11211    11211
memcache.hash_function    crc32    crc32
memcache.hash_strategy    consistent    consistent
memcache.lock_timeout    15    15
memcache.max_failover_attempts    20    20
memcache.protocol    ascii    ascii
memcache.redundancy    1    1

4，下载wordpress memcache插件

wget https://downloads.wordpress.org/plugin/memcached.3.0.1.zip

把object-cache.php解压到wp-content目录下

[root@bogon wp-content]# ls
index.php  languages  object-cache.php  package.xml  plugins  themes  upgrade  uploads
[root@bogon wp-content]# 

最后比较服务器

安装了memcache缓存的版本，首页性能：

3 queries in 0.451 seconds, using 13.56MB memory

没有启用缓存的系统，首页性能：

16 queries in 1.336 seconds, using 12.98MB memory

可以看见有很明显的提升，其他页面都会被优化，缓存到

 启用opcache，再次提速：

3 queries in 0.129 seconds, using 3.48MB memory

php.ini中opcache需要这样加载：

zend_extension=opcache.so

opcache相关配置： 

[opcache]
; Determines if Zend OPCache is enabled
opcache.enable=1

; Determines if Zend OPCache is enabled for the CLI version of PHP
opcache.enable_cli=1

; The OPcache shared memory storage size.
opcache.memory_consumption=528

; The amount of memory for interned strings in Mbytes.
opcache.interned_strings_buffer=8

; The maximum number of keys (scripts) in the OPcache hash table.
; Only numbers between 200 and 100000 are allowed.
opcache.max_accelerated_files=10000

; The maximum percentage of "wasted" memory until a restart is scheduled.
;opcache.max_wasted_percentage=5
"php.ini" 2051L, 74201C written                                                                                      

  
[ldap]
; Sets the maximum number of open links or -1 for unlimited.
ldap.max_links = -1

[mcrypt]
; For more information about mcrypt settings see http://php.net/mcrypt-module-open

; Directory where to load mcrypt algorithms
; Default: Compiled in into libmcrypt (usually /usr/local/lib/libmcrypt)
;mcrypt.algorithms_dir=

; Directory where to load mcrypt modes
; Default: Compiled in into libmcrypt (usually /usr/local/lib/libmcrypt)
;mcrypt.modes_dir=

[dba]
;dba.default_handler=

[opcache]
; Determines if Zend OPCache is enabled
opcache.enable=1

; Determines if Zend OPCache is enabled for the CLI version of PHP
opcache.enable_cli=1

; The OPcache shared memory storage size.
opcache.memory_consumption=528

; The amount of memory for interned strings in Mbytes.
opcache.interned_strings_buffer=8

; The maximum number of keys (scripts) in the OPcache hash table.
; Only numbers between 200 and 100000 are allowed.
opcache.max_accelerated_files=10000