3-tier architecture

Question

Use case : create a website linked to a database.
If I'm going with the 3-tier route, I have to use a General Purpose VM for the web server, a Memory Optimized VM for the database server, what about the application server? What type should I use?

Answer 1

Hello, @Chelsea Haddad !

I would generally recommend starting with a compute optimized VM for an application server, then evaluate the performance of your actual workload and adjust as needed.

What VMs should I use in 3-tier or N-tier architecture?
The official Azure architecture recommendation is going to point you to an N-tier application architecture style that includes but is not restricted to three tiers:

• Azure architecture styles: N-tier architecture style
• Azure database architectures: Windows N-tier application on Azure
• Azure networking architectures: Multi-tier web application built for HA/DR

It's important to note that while N-tier architectures are typically implemented as infrastructure-as-a-service (IaaS) applications, it can be advantageous to use managed services for some parts of the architecture (especially caching, messaging, and data storage).

The compute portion of these architectures vary depending on your needs and while specialized recommendations are made for 3D video rendering, computer-aided engineering, HPC clusters, and more, the general advice is to select VMs that most closely match your on-premises servers. Then measure the performance of your actual workload and adjust the size of the VM as needed.

For a starting point, the compute optimized VMs are recommended for application servers.

N-tier architecture style VM overview with a DMZ/perimeter network:

Windows N-tier application architecture on Azure:

Answer 2

Hello,

It does highly depend on the workload expected in the Application layer itself. Generally, a B-Series or D-Series should be enough, considering the the DB will be hosted in a E-Series.

I would recommend the next link for reference of usage:

https://azure.microsoft.com/en-us/pricing/details/virtual-machines/series/

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Answer 3

Hi @Chelsea Haddad

Good day, Go for compute optimized VM's, as a starting point go with fsV2 if traffic increases, move to FX series.

Another approach could be to divide the load between smaller General purpose Compute machines using a load balancer to start with.

Hope it helps.