Azure VM load balancing vs Traffic Manager

Question

Can anyone explain the distinction between VM load balancing (in the new Azure portal) and the Azure traffic manager (currently only managed from the old portal), and how they interact?

As an example, I've created two VMs attached to each other, sharing a load balanced endpoint. As I understand it, that then will round-robin between the two VMs.

• What happens if I didn't set up a load balanced endpoint (in the new Azure portal), but instead set up Azure traffic manager to load balance between them instead? Is this the same thing?
• Can I use both kinds of load balancing in tandem? (traffic manager set to failover across regions, and use VM load balancing for round robins across availability zones?)

Answer 1

James,

I think you already have most of it figured out.

VM load balancing:

1. Works only with VMs that are in the same region
2. Only does Round Robin Uses a hash-based algorithm for distribution of inbound flows
3. Works at the TCP/UDP level, routing traffic between one or more private endpoints that sit behind a public endpoint

https://www.windowsazure.com/en-us/manage/windows/common-tasks/how-to-load-balance-virtual-machines/

Traffic Manager is different in that:

1. It can work across regions
2. It offers traffic management policies other than round robin (e.g. failover, performance)
3. It works at the DNS level, “routing”** traffic between one or more public endpoints that sit behind a common DNS name

https://azure.microsoft.com/en-us/documentation/articles/traffic-manager-manage-profiles/

You can indeed use the Load Balancer and the Traffic Manager in tandem, you hit the nail on the head there.

--

Vlad

** Traffic manager does not actually route traffic, it just serves to the caller the DNS name of the public endpoint where their traffic should go according to the policies in effect.