Slide 25
Slide 25 text
Your durable configuration data has to live somewhere. On the left we have what it would look like if there was a centralized configuration service that applications spoke
to, we have the customer and order services talking directly to an external configuration service. Again, this could be the key-value store directly or we could have fronted
it by some kind of service providing a simpler interface.
On the right, we’ve introduced a sidecar that acts as a smart proxy to our persistent data store backing the configuration service. Their implementations aren’t
significantly different—the sidecar would behave pretty similarly to an external configuration service, BUT! You could implement identical interfaces, if you so wanted.
There’s a very important, key difference here: the sidecar is local and shares a the physical location of the customer and order services, respectively. So instead of
requiring network traversal, the two processes can communicate via any means available to the host locally.
In our example, we’re going to have them communicate via the filesystem.