Azure Virtual Machine High Availability & Auto Scale LAB1

Azure Virtual Machine High Availability & Auto Scale

Availability Sets is a logical  group of VMs to ensure minimal downtime. Availability Sets will increase the availability of your Applications on and the Availability Zones allows you to deploy your VM’s into different data centers within the same region.

Availability Set for your VM would be spread across update and fault domains but it could happen that your Azure VM is running within the same building .  In case of any disaster to that building then it could be an outage your VM may go down. In such cases to avoid it you can deploy your VM’s to Availability Zones. In this case your VM’s are spread across different buildings but within same Azure Region.

When creating Availability sets keep these principles in mind.

• For redundancy, configure multiple virtual machines in an Availability Set. 
• Configure each application tier into separate Availability Sets. 
• Combine a Load Balancer with Availability Sets. 
• Use managed disks with the virtual machines.

What is an update domain? : An update domain allows Azure to perform incremental or rolling upgrades across a deployment. Each update domain contains a set of virtual machines and associated physical hardware that can be updated and rebooted at the same time. During planned maintenance, only one update domain is rebooted at a time. By default, there are five (non-user-configurable) update domains, but you configure up to twenty update domains.

What is a fault domain?
A fault domain defines a group of virtual machines that share a common set of hardware, switches, that
share a single point of failure. For example, a server rack serviced by a set of power or networking
switches. VMs in an availability set are placed in at least two fault domains. This mitigates against the
effects of hardware failures, network outages, power interruptions, or software updates.

Scale Sets : Virtual machine scale sets are an Azure Compute resource you can use to deploy and manage a set of identical VMs. VM scale sets are designed to support true auto-scale – no pre-provisioning of VMs is required – and as such makes it easier to build large-scale services  targeting big compute, big data, and containerized workloads. So, as demand goes up more virtual machine instances can be added, and as demand goes down virtual machines instances can be removed. The process can be manual or automated or a combination of both.

 

Benefits Scale Set - 

• All VM instances are created from the same base OS image and configuration. This approach lets you easily manage hundreds of VMs without additional configuration tasks or network management. 
• Scale sets support the use of the Azure load balancer for basic layer-4 traffic distribution, and Azure Application Gateway for more advanced layer-7 traffic distribution and SSL termination. 
• Scale sets are used to run multiple instances of your application. If one of these VM instances has a problem, customers continue to access your application through one of the other VM instances with minimal interruption.
• Customer demand for your application may change throughout the day or week. To match customer demand, scale sets can automatically increase the number of VM instances as application demand increases, then reduce the number of VM instances as demand decreases. This is known as autoscale. 
• Scale sets support up to 1,000 VM instances. If you create and upload your own custom VM images, the limit is 300 VM instances. 

LAB  for Azure Virtual Machine High Availability

How to setup Azure Virtual Machine High Availability.

Lets Assume we having 3 Web Servers in different-different location with named as 
Delhi-SRVWeb1DEL  
Mumbai-SRVWeb2MUM
Bangalore -SRVWeb3BLR  

Exercise 1 - Resource Group 

Step 1- Log in Azure Portal and search for Resource Group.
Step 2- Add Resource Group and Select Subscription 
Step 3- Type Resource Group Name i.e RGEastUs
Step 4- Select Region i.e EastUs .
Step 5- Click Create.

Exercise 2 - Availability Sets

Step 1- Search for Availability Sets and Click Add .
Step 2- Select Subscription 
Step 3- Select Resource Group i.e. RGEastUs
Step 4- Select Region i.e EastUs .
Step 5- Type Instance Name : AbltySets

Step 6- Region : East US
Step 7- Rest Keep as default : East US
Step 8- Click Create 

Exercise 3 - Virtual Network (VNet)

  
Step 1- Search for Virtual Network and Click Add. 
Step 2- Enter VNet Name - VNetEast
Step 3- Address Space - 192.168.0.0/16 
Step 4- Select Subscription 
Step 5- Select Region i.e EastUs .
Step 6- Select Resource Group i.e. RGEastUs




Step 7- Subnet Name- i.e. FrontSubnet

Step 8- Address Range - i.e. 192.168.0.0/24

Step 9- Create

LAB 2 - Virtual Machine Deployment with 
Availability Sets Part -2