Since Redis stores data in memory, all data is lost when the server reboots. In the previous chapter, we learned how to set up Redis slaves to replicate data from the master. From the perspective of data redundancy, Redis replication can be used as a way to back up the data.

In order to keep the data safe, Redis also provides mechanisms to persist data to disk. There are two data persistence options: RDB and AOF. RDB is a point-in-time snapshot of Redis data, which is perfect for backups and disaster recovery. AOF is a log of write operations that will be replayed at server startup.

In this chapter, we will introduce how to enable and configure RDB and AOF in Redis. We will also take a look at the file format of RDB and AOF, as well as important configuration parameters to tune when setting up Redis persistence. At the end of this chapter, we will talk about combining RDB and AOF in Redis.