我得是centos 6.3，如果直接用yum安装redis，报错，如下：
[root@CentOS6 etc]# yum install redis
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
* base: mirrors.btte.net
* extras: mirrors.btte.net
* updates: mirrors.btte.net
base | 3.7 kB 00:00
extras | 3.5 kB 00:00
updates | 3.5 kB 00:00
updates/primary_db | 4.6 MB 00:25
Setting up Install Process
No package redis available.
Error: Nothing to do
实际上redia位于第三方的yum源里面，不在centos官方yum源里面，如何解决呢？
1：去下面的网站下载EPEL对应的版本：（epel是fedora维护的yum源，里面软件众多）
http://fedoraproject.org/wiki/EPEL
2：我下载的是这个：
wget http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm
3：安装epel：
rpm -ivh epel-release-6-8.noarch.rpm
warning: epel-release-6-8.noarch.rpm: Header V3 RSA/SHA256 Signature, key ID 0608b895: NOKEY
Preparing... ########################################### [100%]
1:epel-release ########################################### [100%]
4：安装redis：
[root@CentOS6 ~]# yum install redis
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
epel/metalink | 4.1 kB 00:00
* base: mirrors.btte.net
* epel: mirrors.sohu.com
* extras: mirrors.btte.net
* updates: mirrors.btte.net
epel | 4.3 kB 00:00
epel/primary_db | 5.0 MB 00:43
Setting up Install Process
Resolving Dependencies
--> Running transaction check
---> Package redis.x86_64 0:2.4.10-1.el6 will be installed
--> Finished Dependency Resolution
Dependencies Resolved
================================================================================
Package Arch Version Repository Size
================================================================================
Installing:
redis x86_64 2.4.10-1.el6 epel 213 k
Transaction Summary
================================================================================
Install 1 Package(s)
Total download size: 213 k
Installed size: 668 k
Is this ok [y/N]:y
然后再装php-redis扩展
yum install php-redis
重启service httpd restart就可以了。
<?php
$redis = new Redis();
$redis->connect('127.0.0.1',6379);
$redis->set('test','hello world!');
echo $redis->get('test');
?>
测试代码: