In the next sections, we will begin with the simplest architecture and point out the flaws in the design. Gradually, we'll solve them until we have a robust high availability design.
First, let's take a look at the following diagram, which represents the most basic Microsoft Dynamics AX 2012 design. There is a single AOS instance and the AOS connects to a single SQL Server instance, as shown in the following figure:
It goes without saying that this is not a good design when it comes to HA. When either the AOS or SQL Server instance has a failure, the whole environment will be out of order.
We will not discuss the SQL Server issues here because we want to focus on the architecture of the AOS instances. These are the most important when it comes to services.
We should begin by adding redundancy for the AOS instance. We will do this by configuring the application level load balancing.