Cloud concepts
- Benefits of cloud computing: high availability, scalability (vertical = bigger instance, horizontal = more instances), elasticity, agility, and shifting from CapEx to OpEx.
- Service models: IaaS (you manage the OS up — VMs, VNets), PaaS (Azure manages the platform — App Service, Azure SQL), SaaS (fully managed application — Microsoft 365).
- Deployment models: public cloud, private cloud, hybrid cloud. Azure Arc extends Azure management to resources outside Azure, including other clouds and on-premises.
- Consumption-based pricing means you pay only for what you use, with no large upfront hardware investment — the core CapEx-to-OpEx shift.
Azure architecture and services
- Physical structure: regions (geographic areas with one or more datacentres) grouped into region pairs for disaster recovery, further organised into geographies for data-residency and compliance boundaries.
- Availability Zones (physically separate datacentres within a region) protect against datacentre-level failure; Azure resources can also be placed for cross-region resilience.
- Compute: Virtual Machines (full control), Virtual Machine Scale Sets (autoscaling identical VMs), App Service (managed web apps), Azure Container Instances and AKS (containers), Azure Functions (serverless).
- Storage: Blob Storage (object), Disk Storage (attached to VMs), Azure Files (SMB shares), and the redundancy options (LRS, ZRS, GRS) that trade cost for durability.
- Networking: Virtual Network (VNet), VNet peering, VPN Gateway, ExpressRoute (private dedicated connection), and Azure Load Balancer / Application Gateway for distributing traffic.
Azure management and governance
- Cost management tools: Pricing Calculator (estimate before you build), Total Cost of Ownership Calculator (compare on-premises vs. Azure), Azure Cost Management (track and analyse actual spend).
- Governance tools: Azure Policy (enforce organisational rules), resource locks (CanNotDelete, ReadOnly), management groups (organise many subscriptions), and Azure Blueprints for repeatable environment setup.
- Resource Manager (ARM): the deployment and management layer for all Azure resources — resource groups organise related resources, and ARM templates deploy infrastructure as code.
- Monitoring and compliance: Azure Monitor and Azure Service Health for operational visibility; the Microsoft Trust Center and compliance documentation for regulatory questions.
Test yourself on AZ-900
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