Key Points:
- Azure Pricing:
- Understand Pay-as-you-go, Reserved Instances, Spot Instances, and tools like Pricing Calculator and Cost Management.
- SLAs
- Key terms include uptime, availability, and downtime. SLAs vary depending on service configurations (e.g., availability zones).
- Lifecycle
- Services evolve from Preview to General Availability (GA) and may eventually be retired.
1. Azure Pricing
Azure offers flexible pricing models to accommodate different business needs, and understanding how Azure services are priced is crucial for managing costs effectively.
Key Pricing Concepts:
- Pay-as-you-go (PAYG):
- Most common pricing model where you pay for the resources you use. There’s no upfront cost, and billing is based on consumption (compute hours, storage space, etc.).
- Reserved Instances (RIs):
- Pre-purchase resources for 1 or 3 years at a discounted rate compared to PAYG. Ideal for workloads with predictable usage patterns, such as virtual machines.
- Spot Instances:
- Significantly discounted instances but subject to availability. If Azure needs capacity back, the instances may be reclaimed, making them ideal for workloads that can be interrupted.
- Azure Hybrid Benefit:
- Cost savings on Windows Server or SQL Server licenses if you already have licenses with Software Assurance, helping you to use existing licenses in the cloud.
Tools for Pricing and Cost Management:
- Azure Pricing Calculator:
- An online tool to estimate the cost of specific Azure services. It helps you configure different service tiers and see how your usage affects pricing.
- Tool link: Azure Pricing Calculator
- Total Cost of Ownership (TCO) Calculator:
- This helps organizations estimate cost savings by moving workloads to Azure compared to running on-premises data centers (hardware, electricity, cooling, etc.).
- Tool link: TCO Calculator
- Azure Cost Management + Billing:
- A tool available in the Azure portal to monitor, analyze, and control Azure spending. It provides detailed cost insights and recommendations to optimize costs.
Free Services and Trials:
- Azure Free Tier:
- Free services for 12 months, like Virtual Machines (750 hours/month of B1S VM), SQL Database (250GB), Blob Storage (5GB), and others.
- Always free services: Like 1 million requests/month for Azure Functions, 400,000 GB-seconds for serverless code execution.
2. Azure Service Level Agreements (SLAs)
SLAs define the performance and availability standards that Microsoft guarantees for Azure services. They are critical for ensuring uptime and service reliability for your applications.
Key SLA Concepts:
- Uptime:
- SLAs define the guaranteed percentage of uptime for Azure services. For most services, this is 99.9%, but some services have SLAs as high as 99.99% or higher with the right configurations.
- For example, Virtual Machines can have an SLA of 99.9% for a single instance and 99.99% if deployed across Availability Zones.
- Downtime and Availability:
- 99.9% uptime means around 8 hours and 45 minutes of potential downtime per year.
- 99.99% uptime allows for roughly 52 minutes of downtime per year.
- 99.999% uptime (five nines) allows for just 5 minutes of downtime per year.
Improving SLAs:
- Availability Sets:
- Ensures that virtual machines (VMs) are distributed across multiple fault domains (physical hardware separation) and update domains (software updates).
- Availability Zones:
- Physically separate locations within an Azure region. If one zone goes down, services in another zone will continue running, improving uptime.
- Multi-Region Deployment:
- Deploying services across multiple Azure regions for even higher availability and disaster recovery.
Claiming SLA Credits:
If Azure fails to meet the SLA, you may be eligible for service credits. Azure provides SLA credit information on its website. For example, if the SLA for a service is 99.9% and Azure only achieves 99.0%, the customer may receive a 10% service credit for that month.
3. Azure Lifecycle and Service Lifecycle
Understanding the lifecycle of Azure services and how they evolve is important for managing production workloads and planning migrations.
Azure Service Lifecycle:
- Preview Services:
- New Azure services often start in preview. These are beta versions of services that are made available for early testing. While they may not come with SLAs, previews are valuable for testing new features and giving feedback.
- There are two types of previews:
- Private Preview: Requires sign-up or invitation for access.
- Public Preview: Open for anyone to use but typically not recommended for production workloads.
- General Availability (GA):
- After a service has been tested in preview, it moves to General Availability (GA). At this stage, the service is considered production-ready and is covered by the standard SLAs.
Decommissioning/Retirement:
- Occasionally, older services or versions of services may be retired by Microsoft, meaning they are no longer supported or available. Microsoft typically provides advance notice to help users migrate to newer services.
Updates and Patching:
- Azure services are continually updated, but Microsoft handles the underlying infrastructure, meaning you don’t have to worry about patching or security updates for PaaS and SaaS services. IaaS services, like Virtual Machines, still require you to manage OS and application patches unless you use services like Azure Update Management.