Does AWS natively support weighted load balancing?
From what I see, ELB does only support round-robin load balancing (without any configurable weights). I have not found reliable documentation on it, though.
The easiest thing that I can think of is to put a load balancer like Nginx in front of it, for example:
upstream backend {
server backend1.example.com weight=1;
server backend2.example.com weight=2;
server backend3.example.com weight=4;
}
Here, out of seven requests, one will go to backend1, two to backend2, and four to backend4.
It will work, but it also means you have to setup a server with Nginx just for that. If AWS would directly support weighted load balancing that would be far easier to setup.
Best Answer
The How Elastic Load Balancing Works documentation page states:
The Elastic Load balancing service does not support weighted round-robin (where you specify the weights).
You could use Amazon Route 53 with a Weighted Routing Policy. From the Choosing a Routing Policy documentation page: