1.简介

1.1Memcached

Memcached是一款开源的、高性能的纯内存缓存服务软件。MySQL数据库属于磁盘上的数据库，数据的读写较慢；而Memcached数据库属于内存中的数据库，读写速度快，但数据容易丢失。Memcached天生不支持分布式集群，只能通过程序支持分布式存储。使用Memcached数据库，提高用户访问网站速度，降低MySQL数据库服务器压力，提高网站的并发访问，因此工作中，MySQL+Memcached搭配使用。

1.2Memcached工作过程

2.系统环境准备

[root@cache01 ~]# cat /etc/re

RedHat-release  resolv.conf   

[root@cache01 ~]# cat /etc/re

redhat-release  resolv.conf   

[root@cache01 ~]# cat /etc/redhat-release

CentOS Linux release 7.2.1511 (Core)

[root@cache01 ~]# uname -r

3.10.0-327.el7.x86_64

[root@cache01 ~]# getenforce

Disabled

[root@cache01 ~]# systemctl status firewalld.service

● firewalld.service – firewalld – dynamic firewall daemon

  Loaded: loaded (/usr/lib/systemd/system/firewalld.service; disabled; vendor preset: enabled)

  Active: inactive (dead)

[root@cache01 ~]# ifconfig

eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500

        inet 10.0.0.21  netmask 255.255.255.0  broadcast 10.0.0.255

        inet6 fe80::20c:29ff:fee1:ad7  prefixlen 64  scopeid 0x20<link>

        ether 00:0c:29:e1:0a:d7  txqueuelen 1000  (Ethernet)

        RX packets 3228  bytes 815585 (796.4 KiB)

        RX errors 0  dropped 0  overruns 0  frame 0

        TX packets 419  bytes 52728 (51.4 KiB)

        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

eth1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500

        inet 172.16.1.21  netmask 255.255.255.0  broadcast 172.16.1.255

        inet6 fe80::20c:29ff:fee1:ae1  prefixlen 64  scopeid 0x20<link>

        ether 00:0c:29:e1:0a:e1  txqueuelen 1000  (Ethernet)

        RX packets 0  bytes 0 (0.0 B)

        RX errors 0  dropped 0  overruns 0  frame 0

        TX packets 23  bytes 1698 (1.6 KiB)

        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536

        inet 127.0.0.1  netmask 255.0.0.0

        inet6 ::1  prefixlen 128  scopeid 0x10<host>

        loop  txqueuelen 0  (Local Loopback)

        RX packets 0  bytes 0 (0.0 B)

        RX errors 0  dropped 0  overruns 0  frame 0

        TX packets 0  bytes 0 (0.0 B)

        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

3.服务端部署Memcached服务

3.1安装memcached

[root@cache01 ~]# yum install -y memcached

3.2启动memcached服务

[root@cache01 ~]# systemctl start memcached.service

3.3测试

[root@cache01 ~]# printf “set fengfyu 0 0 5\r\n12345\r\n”|nc 10.0.0.21 11211      —写入数据

STORED

[root@cache01 ~]# printf “get fengfyu 0 0 5\r\n12345\r\n”|nc 10.0.0.21 11211    —读取数据

VALUE fengfyu 0 5

12345

END

ERROR

4.web服务器客户端部署memcached

4.1编译安装memcached

[root@web01 tools]# tar xf memcache-2.2.5.tgz

[root@web01 tools]# cd memcache-2.2.5/

[root@web01 memcache-2.2.5]# /application/php/bin/ph

[root@web01 memcache-2.2.5]# /application/php/bin/phpize

Configuring for:

PHP Api Version:        20121113

Zend Module Api No:      20121212

Zend Extension Api No:  220121212

[root@web01 memcache-2.2.5]# ./configure –enable-memcache –with-php-config=/application/php/bin/php-config –with-zlib-dir && make && make install

4.2使php与memcached关联

sed -i ‘$a extension=memcache.so’ /application/php/lib/php.ini

4.3启动php

/application/php/sbin/php-fpm

4.4客户端测试

[root@web01 www]# cat /application/nginx/html/www/mc.php

<?php

$memcache = new Memcache;

$memcache->connect(‘10.0.0.21’, 11211) or die (“Could not connect”);

$memcache->set(‘fengyu’, ‘hello,world’);

$get_value = $memcache->get(‘fengyu’);

echo $get_value;

?>

[root@web01 www]# printf “get fengyu\r\n”|nc 10.0.0.21 11211

VALUE fengyu 0 11

hello,world

END

5.web界面管理maceched

5.1解压memadmin包到/application/nginx/html/www/目录

[root@web01 tools]#  tar xf memadmin-1.0.12.tar.gz -C /application/nginx/html/www/

5.2浏览器访问

http://10.0.0.7/memadmin

6.Memcached Session共享

6.1通过程序实现，web01只需要往memcahce写session，web02从memcahce读session，当作普通数据读写（更具有通用性）

6.1通过php的配置文件，php默认将session存储在文件中，修改为存储在memcached中

sed -i ‘s#session.save_handler = files#session.save_handler = memcache#;$a session.save_path = “tcp://10.0.0.21:11211″‘ /application/php/lib/php.ini