Describe the benefits of high availability and scalability in the cloud

High availibility

The SLA (service-level agreement) defines the percentage of time where the service is availible. It also defines the credit given back by the cloud provider, when the SLA is not met. Usually the availibility in Azure is 99% or 99.9%.

This is a big difference.

Scalability

This is the ability to increase or decrese resources. This can be cost effective and when a peak in traffic is detected, you can easily increase the resources

There we differenciate between two types of scalability:

• Vertical scaling: This is the ability to increase the processing power of one virtual machine for example. So if you are creating an App and this needs more processign power, you would just give the one virtual machine one more CPU or give a bit more RAM.
• Horizontal scaling: With horizontal scaling, you add a complete new virtual machine or a new container which contains a duplicate of the application. Here we would have multiple threads of the same application running.

Describe the benefits of reliability and predictability in the cloud

Reliability

This is the ability to keep the application running, in case one instance fails. Let's say the swiss mountains experience an earthquake and the datacenter in the mountain is destroyed. In this case the application should still be running, because there is a datacenter in Zurich which has the same application running and can take over the traffic. This is also called Decentralization.

Predictability

This is the ability to know how much resources you need. This is important for the cost. If you know how much resources you need, you can plan the cost for the next month.

Performance

Autoscaling, load balancing and also high availibility are examples, which can improve the performance predictability. All of these tool can help to predict the performance and also take action. For example if the laod balancer detects a peak in traffic, it will automatically create more resources on Azure.

Cost

You can predict the cost thanks to the dashboards availible on Azure.

Describe the benefits of manageability in the cloud

The manageability is a big benefit of the cloud.

Management of the cloud

• Scale resources when needed
• Deploy resources thanks to templates
• Simplified monitoring of resource health
• Automated alerts

Management in cloud

There are multiple tools to manage in the cloud Here I will list the possibilities in Azure:

1. Azure portal (Web)
2. Azure CLI (Command line)
3. Azure PowerShell (Command line)
4. Azure Cloud Shell (Command line)
5. Using Azure API (API)