Best IaaS Architecture - Azure Challenge

Designing an IT infrastructure is totally dependant on the services, products, applications and many other things that an enterprise/organization/company provides to the user. It is also depends on which development model the company is preserving for development. So it is very difficult to develop a generalized IT infrastructure but we can use a basic IT infrastructure module at the beginning stage and can change accordingly depending on future needs.

In this case study, we will look at how to design and develop a simple IT infrastructure, how to balance the incoming traffic load among available resources (VMs), how to make disaster recovery-based architecture using an Availability Set and also how to use amazing Azure Services in a simple way to make standard IT infrastructure.

2. Type: IaaS (Infrastructure as a Service).

3. Architecture diagram



4. Solution Details

The following are the features, technologies used, existing / potential end-users, existing/potential customers and so on:

1. High Security due to overall architecture is divided into multipe subnets. Each tier of VMs are launched into different private subnets that provide one more security layer in the Virtual Private Network. 
2. High Availability due to two Availability Zones. Availability Zones have the same VMs and they run individually.
3. Different Load Balancer provides different features. We can change this load balancer type at any time. 
   
   1. Performance: Select Performance when you have endpoints (cloud services or web sites) in multiple datacenters (also known as regions) and you want to direct the user to the endpoint with the lowest latency. 
   2. Failover: Select Failover when you have endpoints in the same or different datacenters and want to use a primary endpoint for all traffic, but provide backups in case the primary or the backup endpoints go offline.
   3. Round Robin: Select Round Robin when you want to distribute the load equally across a set of endpoints in the same datacenter or across various datacenters. 
4. Disaster Recovery (Warm Standby) can be possible using this architecture. We can maintain a standby to any one Availability Zone instance and when needed the environment rapidly scales up (in other words activating another Availability Zone) to meet full production demands.
5. Primary and Secondary Database with SQL Data Synch service provides an always stand by copy of the original database.

5. Economic viability of the Solution
Today companies know disaster is not a matter of if, but when. It is very important to take precautions before something happens. According to a study done by the University of Oregon, every dollar spent on hazard mitigation, including Disaster Recovery, saves companies four dollars in recovery and response costs. In more detail to cost savings, smart companies also view Disaster Recovery as critical to their survival. For example, 51% of companies that experienced a major data loss closed within two years (Source: Gartner), and 44% of companies that experienced a major fire never re-opened (Source: EBM). Again, disaster is not a matter of if, but when. So we need to be ready for Disaster Recovery and to save its cost.

6. Relevant screenshots from the Azure portal:

1. All VMs
   
2. VNET Network
   
3. Subnets
   
4. Availability Zone A VMs
   
5. Availability Zone B VMs