Azure Classroomnotes 06/Sep/2022

Scenario/Problem Statement

Consider the following architecture of an popular e-commerce application.
This application runs in the datacenter owned by the organization in Hyderabad Location.
There are offer days announced by ecommerce application, This would increase number of users
To solve this problem, the options which we have is scaling.
There are two types of Scaling
- Vertical Scaling: Increase Hardware resources to your server/system.
- Horizontal Scaling: Increase number of Systems/server.
For the above problem, we need to do horizontal scaling.
This will have two kinds of costs
- Capex => Capital investments
- Opex => Ongoing investments
When we use any cloud, we deal with servers which are virtual in nature and we pay the bill for the usage mostly hourly as a unit.
If we can run all of the architecture shown above on these vm’s we pay for the usage.
All the clouds support increasing number of vms automatically based on some metric and decreasing number of vms when the metric is below some threshold which is referred as elasticity.

Hypervisor is a software which helps in creating Virtual Machines (VM).
There can be more than one VMs on a physical machine
Each Virtual Machine gets
- Virtual CPU
- Virtual RAM
- Virtual Disk
When the VM is running all of the above resources will be used, but when we shutdown the VM then only Virtual Disk will be active.
Now if we want to charge or build a business model
- Size Based
  - Size of Virtual CPU
  - Size of VIrtual RAM
  - Size of Virtual Disk
- Unit: Hourly for CPU and RAM + Hourly for Disk