Setting up ELB on AWS for Node.js

Question

I have a very basic question but I have been searching the internet for days without finding what I am looking for.

I currently run one instance on AWS.

That instance has my node server and my database on it.

I would like to make use of ELB by separating the one machine that hosts both the server and the database:

1. One machine that is never terminated, which hosts the database
2. One machine that runs the basic node server, which as well is never terminated
3. A policy to deploy (and subsequently terminate) additional EC2 instances that run the server when traffic demands it.

First of all I would like to know if this setup makes sense.

Secondly,

I am very confused about the way this should work in practice:

Do all deployed instances run using the same volume or is a snapshot of the volume is used?

In general, how do I set such a system? Again, I searched the web and all of the tutorials and documentations are so generalized for every case that I cannot seem to figure out exactly what to do in my case.

Any tips? Links? Articles? Videos?

Thank you!

Answer 1

You would have an AutoScaling Group with a minimum size of 1, that is configured to use an AMI based on your NodeJS server. The AutoScaling Group would add/remove instances to the ELB as instances are created and deleted.

EBS volumes can not be attached to more than one instance at a time. If you need a shared disk volume you would need to look into the EFS service.

Yes you need to move your database onto a separate server that is not a member of the AutoScaling Group.