Zone redundancy must be enabled when creating a container app environment. Your environment must contain a virtual network (VNet) with an infrastructure subnet. To properly distribute replicas, you must configure the minimum and a maximum number of app replicas to a value divisible by 3. The minimum number of replicas should be 3 or more.
To improve the reliability of your Azure zones, you can create a redundant zone configuration via the Azure portal.
To create a container application in a zone-redundant enabled environment using the Azure portal:
- Go to the Azure portal.
- From the search box for Container Apps.
- Select Container Apps.
- Create New in the Container Apps Environment field to open the Create Container Apps Environment panel.
- Enter the environment name.
- Enabled for the Zone redundancy.
Zone Redundancy required a virtual network with an infrastructure subnet. You can choose an existing VNET or create a new one. When creating a new VNET, you can accept the defaults or customize them.
- Go to Networking tab.
- To assign a custom VNET name, select Create New in the Virtual Network field.
- In the Infrastructure subnet field, select create new to assign a custom name to your infrastructure subnet.
- You can choose Internal or External for the Virtual IP.
- Select Create.
For more details- Zone redundancy