5.4 Service discovery and configuration

As your use of Redis and other services grows over time, you’ll eventually come to a situation
where keeping configuration information can get out of hand. It’s not a big
deal when you have one Redis server, one database server, and one web server. But
when you have a Redis master with a few slaves, or different Redis servers for different
applications, or even master and slave database servers, keeping all of that configuration
can be a pain.

Typically, configuration information for connecting to different services and servers
is contained in configuration files that are stored on disk. And in situations where
a machine breaks down, a network connection goes down, or something else causes us
to need to connect to a different server, we’ll usually need to update a number of configuration
files in one of a number of locations. In this section, we’ll talk about how we
can move much of our configuration out of files and into Redis, which will let applications
almost configure themselves.

Let’s start with a simple live configuration to see how Redis can help us.