Redis Tips & Tricks #1 - Memory

It's neither a tip, nor a trick. It's more a statement:

ALL data is kept in memory

"No shit" some of you might say, but I actually have to confess: I did not know that when I started using redis. I always assumed "there is a file on the disk, that is where my data lives".

The truth is: all of redis' data is kept in memory and from time to time it is also written to disk

This has 2 effects:

  • As the database grows, so grows its memory consumption
  • If your machine crashes all data that hasn't been written to the disk is lost.

So keep that in mind when you want to use redis.