Chapter 12. Decoupling your infrastructure: ELB and SQS
This chapter covers
- The reasons for decoupling a system
- Synchronous decoupling with load balancers
- Asynchronous decoupling with message queues
Imagine that you want some advice on using AWS from us, and therefore we plan to meet in a café. To make this meeting successful, we must
- Be available at the same time
- Be at the same place
- Find each other at the café
The problem with our meeting is that it’s tightly coupled to a location. We can solve that issue by decoupling our meeting from the location, so we change plans and schedule a Google Hangout session. Now we must
Google Hangout (this also works with all other video/voice chats) does synchronous decoupling. It removes the need to be at the same place while still requiring us to meet at the same time.
We can even decouple from time by using an e-mail conversation. Now we must
- Find each other via email
Email does asynchronous decoupling. You can send an email when the recipient is asleep, and they’ll respond when they’re awake.