美国VPS的redis持久化数据库的方法：

快照的方式持久化到磁盘，配置代码如下：

save 900 1

save 300 10

save 60 10000

上面的配置规则意思如下:

# In the example below the behaviour will be to save:

# after 900 sec (15 min) if at least 1 key changed

# after 300 sec (5 min) if at least 10 keys changed

# after 60 sec if at least 10000 keys changed