Problem Statement 1

Complex IaaS Problem Statement: Global Enterprise CRM Deployment

In accordance with your requirements for a Complex scenario involving New Infrastructure Deployment on Azure IaaS, here is the problem statement designed to test your architectural and service delivery skills.

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1. CAF Strategy & Plan (Business Stakeholder Persona)

• Business Motivation: “Our organization is launching a proprietary, high-performance CRM to support our expansion into the European market. Due to strict data sovereignty laws and legacy application dependencies, we cannot use PaaS; we require full control over the operating system and networking stack.”
• Business Outcomes: The solution must support 10,000 concurrent users with a target Service Level Agreement (SLA) of 99.99% availability.
• Workload Profile: A distributed, 3-tier monolithic application consisting of a Web Front-end, an Application Logic layer, and a heavy SQL-based Database backend.

2. CAF Ready & Adopt (Landing Zone)

• Requirement: The infrastructure must be deployed into a Hub-and-Spoke landing zone. You are responsible for the “Spoke” design, assuming the “Hub” already provides centralized firewalling and ExpressRoute connectivity.

3. Discovery Report: Required Business Logic (Technical Architect Persona)

Because this is a new deployment, this report defines the High-Level Design (HLD) and Low-Level Design (LLD) requirements of the application software provided by the dev team:

• Component Description:
  • Web Tier: 4x Windows Server 2022 instances (IIS).
  • App Tier: 4x Ubuntu 22.04 LTS instances running Java-based middleware.
  • Database Tier: A 2-node SQL Server 2022 Failover Cluster Instance (FCI) on Windows Server, requiring Shared Storage and high IOPS.
• Application HLD: The app uses a synchronous communication model. The Web tier calls the App tier via a REST API, and the App tier communicates with the DB via a dedicated service account.
• Application LLD (Requirements):
  • Web/App VMs require at least 8 vCPUs and 32GB RAM.
  • The Database requires 16 vCPUs, 128GB RAM, and sub-millisecond disk latency.

4. Source Workflow Diagram (Logic Flow)

1. User Access: External users hit a public-facing entry point via HTTPS (Port 443).
2. Web-to-App: The Web servers forward requests to the Application servers on Port 8080.
3. App-to-DB: The Application servers query the SQL Database cluster on Port 1433.
4. Admin Access: Developers require secure RDP/SSH access for monthly patching.

5. WAF Pillars (Constraints)

• WAF Security:
  • Identity: All VM login access must be governed by Azure Entra ID.
  • Traffic: Implement a Zero-Trust model using Network Security Groups (NSGs) and Application Security Groups (ASGs). No direct internet access is allowed for App or DB tiers.
  • Secrets: Disk encryption keys and SQL credentials must be stored in Azure Key Vault.
• WAF Reliability: The design must survive a Zone failure. You must use Availability Zones (AZs) for all tiers.
• WAF Cost Optimization: The monthly budget for this spoke is $8,000 USD. You must use Azure Reserved Instances and Azure Hybrid Benefit calculations where applicable.
• WAF Operational Excellence: The infrastructure must be monitored via Azure Monitor, with automated alerts for VM heartbeats and Disk space.

6. Technical Boundary

• Strictly IaaS: You are forbidden from using Azure SQL Database (PaaS) or Azure App Service. Everything must run on Virtual Machines.
• Networking: You must define the VNet CIDR, Subnetting (Web, App, DB, and Management), and Load Balancing (Internal vs. External).

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The Challenge (Your Deliverables)

To complete this design phase, you must now produce:

1. Target State HLD: The high-level Azure IaaS architecture.
2. Target State LLD: Detailed configurations (VNet CIDR, Subnet ranges, VM SKUs like D-Series or E-Series, and Disk types like Premium SSD v2 or Ultra Disk).
3. Azure Workflow Diagram: A description of how traffic flows securely through your Azure design.
4. Component Mapping: A table mapping the dev team’s requirements to specific Azure IaaS services.

Are you satisfied with this problem statement, and would you like to proceed with creating these deliverables?