Redis 4.x Cookbook

How it works...

RDB works like a camera for the data memory of Redis. Once the trigger policy is reached, it will take a photo of the data in Redis by dumping all the data into a file on the local disk. Before introducing this process in detail, we'll first explain the value of the save option, which determines the trigger policy of RDB mentioned in the previous section. The pattern of the value is x₁, y₁, x₂, y₂,.... That means, dumping the data in Redis after x seconds if at least y keys have been changed and no dumping process is in progress.

For the preceding example, 900 1 means that, once at least 1 key has changed within 900 seconds, an RDB snapshot will be taken. There can be more than one policy in the save option to control how ...