AZ-900 Concept Map (Mind Map): Skill area 1
Every topic from Skill area 1 of the exam on one page, with the pairs the exam swaps to trick you. It's about 25-30% of your score.
1.1 Describe cloud computing
What the cloud is, who is responsible, the cloud models and how you pay
What the cloud is
- Cloud computing
- Delivering computing services (servers, storage, databases, networking, software) over the internet. You rent what you need, when you need it, instead of buying and running your own hardware.
- On-premises
- IT that runs on hardware your company owns, in its own building or datacenter. You buy, install, power, cool and repair everything yourself.
Shared responsibility model
- Shared responsibility model
- The split of security and management duties between Microsoft and the customer. The more the service is managed (IaaS, then PaaS, then SaaS), the more Microsoft takes on.
- Always the customer's job
- Information and data, devices (phones and PCs), and accounts and identities stay with the customer in every service type.
- Always Microsoft's job
- The physical datacenter, the physical network and the physical hosts are always Microsoft's responsibility.
- Varies by service type
- Operating system, network controls, applications, and identity and directory infrastructure shift between customer and Microsoft depending on IaaS, PaaS or SaaS.
Cloud models
- Public cloud
- Built, controlled and maintained by a cloud provider, shared by many customers. No upfront hardware cost, fast to provision, pay as you go.
- Private cloud
- A cloud used by a single organization, hosted on-site or in a dedicated offsite datacenter. Full control, but the organization pays for the hardware and its upkeep.
- Hybrid cloud
- A private cloud (or on-premises IT) and a public cloud working together, so workloads can run where they fit best.
- Multicloud
- Using two or more public cloud providers at the same time, for example to use the best features of each or during a migration.
- Azure Arc
- Manages servers, Kubernetes clusters and databases outside Azure (on-premises or in other clouds) from Azure, with the same tools and policies.
- Azure VMware Solution
- Runs VMware workloads in Azure on dedicated hardware, so a VMware shop can move to the cloud without rebuilding its VMs.
Paying for what you use
- Consumption-based model
- You pay only for the resources you use, for as long as you use them. No upfront cost, and you stop paying when you stop using.
- Capital expenditure (CapEx)
- A one-time, upfront spend on physical things, such as buying servers or building a datacenter. Its value is spread over years.
- Operational expenditure (OpEx)
- Spending on services or products as you use them, billed regularly. Cloud computing is OpEx.
- Economies of scale
- Because Microsoft buys and runs hardware at huge volume, its cost per unit is lower, and part of that saving reaches customers as lower prices.
- Pay-as-you-go
- The default Azure pricing: pay the list rate per second, hour or unit used, with no commitment. Most flexible, highest unit price.
- Azure Reservations
- Commit to a specific resource type (such as a VM size in a region) for 1 or 3 years in exchange for a large discount, up to 72% off pay-as-you-go.
- Azure savings plan for compute
- Commit to a fixed hourly spend on compute for 1 or 3 years. The discount, up to 65% off pay-as-you-go, applies automatically across eligible compute services, sizes and regions.
- Azure Spot Virtual Machines
- VMs that use spare Azure capacity at a deep discount. Azure can take them back (evict them) when it needs the capacity.
- Azure Hybrid Benefit
- Reuse Windows Server and SQL Server licenses you already own (with Software Assurance), or Red Hat and SUSE Linux subscriptions, to pay less in Azure.
Serverless
- Serverless
- A model where the provider runs, scales and maintains the servers for you. Code runs on events, and you pay only while it runs.
- Azure Functions
- Serverless code: a small function runs when an event happens (an HTTP call, a timer, a new file) and scales automatically.
- Azure Logic Apps
- Serverless workflows built in a visual designer that connect apps and services with ready-made connectors.
1.2 Describe the benefits of using cloud services
Availability, scale, reliability, predictability, security, governance and manageability
Staying up
- High availability
- Keeping an app available with as little downtime as possible, even when something fails, often by running copies in several places.
- Service-level agreement (SLA)
- Microsoft's formal commitment on uptime and connectivity for a service, written as a percentage such as 99.9% or 99.99%. If it is missed, customers can get service credits.
- Reliability
- The ability of a system to recover from failures and keep working. The cloud's spread across the world lets you deploy in several regions so one failure doesn't stop you.
- Geo-distribution
- Deploying resources in datacenters around the world so users are served close to them and a regional outage hits only part of the system.
Growing and shrinking
- Scalability
- The ability to adjust resources to meet demand: add resources when traffic grows, remove them when it drops, and pay only for what you use.
- Vertical scaling (scale up or down)
- Make one resource more or less powerful: more or fewer CPUs, more or less memory on the same VM.
- Horizontal scaling (scale out or in)
- Add or remove instances of a resource, such as more VMs behind a load balancer when traffic rises.
- Autoscale
- Rules that add or remove resources automatically based on load or a schedule, without a person stepping in.
Knowing what to expect
- Performance predictability
- Confidence that the app performs as expected, thanks to features like autoscale, load balancing and high availability.
- Cost predictability
- Forecasting what the cloud will cost, using real-time tracking, cost analysis and tools such as the pricing calculator.
- Load balancing
- Spreads incoming traffic across several instances so none is overloaded, which keeps performance steady and survives the loss of one instance.
Protecting and controlling
- Security in the cloud
- Pick the level of control you want: IaaS when you need to manage patches and settings yourself, PaaS or SaaS when you want patches applied for you. The provider also protects against threats like DDoS attacks.
- Governance in the cloud
- Keeping deployments in line with company standards and regulations, using templates, policies and compliance auditing that can flag or fix drift.
Managing
- Management of the cloud
- Managing the resources themselves: scale automatically, deploy from templates, monitor health, replace failed resources and get alerts.
- Management in the cloud
- The ways you work with your cloud: through a web portal, a command-line interface, APIs or PowerShell.
1.3 Describe cloud service types
IaaS, PaaS and SaaS, and when to pick each
The three service types
- Infrastructure as a service (IaaS)
- Rent the raw building blocks: virtual machines, storage and networking. Microsoft runs the hardware; you manage the operating system, apps and data.
- Platform as a service (PaaS)
- A ready-made environment to build and run apps. Microsoft manages the hardware, operating system, patching and runtime; you bring code and data.
- Software as a service (SaaS)
- A finished application you use over the internet, such as email or office apps. Microsoft runs everything; you manage your data, users and settings.
Typical use cases
- Lift-and-shift migration
- Moving existing servers to the cloud as they are, rebuilding them as VMs with little change. A classic IaaS use case.
- Test and development environments
- Quick, temporary environments that are set up and torn down as needed. Often IaaS, for full control over the setup.
- Development framework
- A PaaS use case: developers use ready components to build cloud apps faster, without managing servers.
- Analytics and business intelligence
- A PaaS use case: managed tools to analyze data and find insights without running the underlying infrastructure.
- Email, messaging and business apps
- Typical SaaS: email, office productivity, finance and customer relationship apps, used straight from the browser.
Part of the Microsoft Azure Fundamentals (AZ-900) Study Kit: Concept Maps, Flashcards and practice questions. Also free: the Skill area 1 flashcards. New to the exam? Read the AZ-900 study guide.