Redis是一个高大性能的键值存储系统， 它支持许多种数据结构，如字符串、列表、集合、哈希表和有序集合。Redis还支持Lua脚本， 这使得开发者能够在Redis服务器端直接施行Lua脚本，从而搞优良应用程序的性能。

准备干活

在开头之前，请确保你的CentOS系统已经安装了Redis。如果没有安装， 能按照以下步骤进行安装：

sudo yum install epel-release
sudo yum install redis

启动Redis服务

安装完成后启动Redis服务：

sudo systemctl start redis

确保Redis服务正在运行

你能用以下命令检查Redis服务是不是正在运行：

sudo systemctl status redis

配置Redis以支持Lua脚本

Redis默认支持Lua脚本，无需额外配置。但是你能通过配置文件进行一些设置，比方说设置Lua脚本的施行时候管束。

编辑Redis配置文件并添加以下行：

lua-time-limit 5000

这玩意儿设置将Lua脚本的施行时候管束为5000毫秒。你能根据需要调整这玩意儿值。

保存配置文件后沉新鲜启动Redis服务以使更改生效：

sudo systemctl restart redis

编写Lua脚本

你能用Redis客户端来施行Lua脚本。

local current_time = os.time
return current_time

要施行这玩意儿脚本，用以下命令：

redis-cli eval "return os.time" 0

这将返回当前时候的Unix时候戳。

用EVALSHA命令施行Lua脚本

如果你已经将Lua脚本存储在Redis中，能用EVALSHA命令来施行它。先说说将脚本保存到Redis中，并获取它的SHA1散列值。然后用这玩意儿散列值来施行脚本：

redis-cli script load "return os.time"
1) "9b6b1b6a9b9b6c8b9a8b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a9b9a