An Availability Set is a logical grouping capability that you can use in Azure to ensure that the VM resources you place within it are isolated from each other when they are deployed within an Azure datacenter.
Azure ensures that the VMs you place within an Availability Set run across multiple physical servers, compute racks, storage units, and network switches
In this post, you will learn how to increase the availability and reliability of your Web Servers on Azure using a capability called Availability Sets.
Building the Network
Enter the following values on the Create virtual network pane
|Subnet address range||10.0.1.0/24|
|Resource group||Leave Create new selected, and then enter MyApp.|
|Subscription and location||Select your subscription and location.|
then click Create:
Create a network security group
Enter a Name for the network security group, select your Subscription, create a new Resource group, select a Location, and then select Create.
Create a security rule
Select the network security group from the list that you want to add a security rule to.
Select Inbound security rules under SETTINGS. Several existing rules are listed. Some of the rules you may not have added.
When a network security group is created, several default security rules are created in it.
You can’t delete default security rules, but you can override them with rules that have a higher priority.
Associate network security group to Subnet
Select Network security group, you want to associate to the Subnet,
Creating an Availability Set for the Web Servers
Log in to the Azure portal at http://portal.azure.com.
Select Create a Resource in the upper left corner. Type in Availability Set and select it. Click on Create
Deploying the Web Servers
In the Basics tab, under Project details, make sure the correct subscription is selected and then choose to Create new resource group. Type the MyApp for the name.
Under Instance details, type WEB1 for the Virtual machine name and choose West Europe for your Location.
Choose Availability Options and Availability Set
Leave the other defaults.
Repeat the same steps to create WEB2 VM.
Create an application gateway
Azure Application Gateway is a web traffic load balancer that enables you to manage traffic to your web applications
Enter these values for the application gateway:
MyAppG– for the name of the application gateway.
MyApp – for the new resource group.
Accept the default values for the other settings and then click OK.
Click Choose a virtual network, then Select these values for the virtual network:
Under Frontend IP configuration ensure IP address type is set to public, and under Public IP address, ensure Create new is selected.
Type myAppip for the public IP address name. Accept the default values for the other settings and then click OK.
Review the settings on the summary page, and then click OK to create the virtual network, the public IP address, and the application gateway.
It may take several minutes for the application gateway to be created.
Wait until the deployment finishes successfully before moving on to the next section.
Add backend servers
Click All resources, and then click MyAppG.
Click Backend pools. A default pool was automatically created with the application gateway.
Under Targets, click IP address or FQDN select Virtual machine.
Under Virtual Machine, add WEB1 and WEB2 virtual machines and their associated network interfaces.