Essential Azure compute concepts

Azure Virtual Machines

VMs are an ideal choice when you need:

• Total control over the OS

• The ability to run custom software

• To use custom hosting configurations

When to use virtual machines:

• During testing and development

• When running applications in the cloud

• When extending your datacenter to the cloud

• During disaster recovery

Scaling VMs

Availability set

When the VM is part of an availability set, updates are sequenced so that not all the associated VMs are rebooted at the same time. They are put into different update domains

With an availability set you get:

• Up to three fault domains that have a server rack with dedicated power and network resources

• Five logical update domains which then can be increased to 10

There is no cost for an availability set, just for the VMs in the set

Virtual Machine Scale Sets

Virtual machine scale sets let you create and manage a group of identical, load balanced VMs.

This allows you to centrally manage, configure and update many VMs to provide highly available applications.

Azure Batch

Azure batch enables large scale job scheduling and compute management

Batch:

• Starts a pool of compute VMs for you

• Installs applications and staging data

• Runs jobs with as many tasks as you have

• Identifies failures

• Requeues work

• Scales down the pool as work completes

Containers

Azure Container Instances

PaaS to upload containers and execute them directly with automatic elastic scale

Azure Kubernetes Service

A complete orchestration service for containers with multiple architectures with multiple containers

Microservice architecture

Breaking solutions into smaller, independent pieces. This allows the separate components of the app to be maintained, scaled or updated independently.

Migrating to containers

The process is as follows:

1. Convert the application to containers and publish to Azure Container Registry

2. Deploy the containers to an AKS cluster

3. Azure AD controls access to AKS resources

4. You access Azure services

5. Optionally, AKS is deployed with a virtual network

Azure App Service

Costs

You pay for the compute resources your app uses. The app service plan determines how much hardware is devoted to the host. There’s even a free tier for low traffic sites

Types of app services

• Web apps - Host web apps

• API apps - Build REST-based Web APIs

• Web Jobs - Run a program or script in the same context as a web app. They can be scheduled or run by a trigger

• Mobile app back ends

  • Store mobile app data in a cloud based SQL database

  • Authenticate customers

  • Send push notifications

  • Execute custom back end logic

Serverless

Serverless encompasses three ideas:

• Abstraction of servers - Don’t need to manage them

• Event-driven scale - Code runs when events come in

• Micro billing - Only pay for the time code runs

Azure functions

Azure functions are ideal for when you’re only concerned about the code running your service. They commonly perform work in response to an event.

Azure functions scale automatically based on demand.

Azure functions can be either:

• Stateless - Behave as if they’ve been restarted every time they respond to an event

• Stateful - A context is passed through the function to track prior activity

Azure Logic Apps

Logic apps execute workflows designed to automate business scenarios and built from predefined logic blocks.

Every logic app workflow starts with a trigger. Azure Logic apps can be designed without code.

Comparison