Specify how many update operations there are within a long period of time, and then synchronize the data to the data file. Multiple conditions can be used
save <seconds> <changes>
Redis默认配置文件中提供了三个条件：
save 900 1
save 300 10
save 60 10000
分别表示900秒（15分钟）内有1个更改，300秒（5分钟）内有10个更改以及60秒内有10000个更改。
怎么理解 ？
![[Web front-end] Node.js quick start](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
If any condition is triggered, the data in the memory will be synchronized to the disk.