> ## Documentation Index > Fetch the complete documentation index at: https://notes.kodekloud.com/llms.txt > Use this file to discover all available pages before exploring further. # Summary Maintaining Pipelines > This article reviews pipeline health, optimization, and migration in Azure DevOps for the AZ-400 exam and practical DevOps applications. Welcome to the concise review of pipeline health, optimization, and migration in Azure DevOps. This summary will reinforce the key concepts you need for the AZ-400 exam and real-world DevOps practices. *** ## 1. Discovering Pipeline Health Pipeline health ensures reliable, predictable releases. Focus on tracking the right metrics and using Azure DevOps analytics tools. ### Key Metrics to Monitor | Metric | Description | Example Threshold | | ------------------- | ------------------------------------------ | ----------------- | | Build Success Rate | Percentage of successful builds | ≥ 95% | | Test Pass Rate | Ratio of passed vs. total tests | ≥ 98% | | Mean Time to Repair | Average time to fix a broken build or test | ≤ 30 minutes | | Flaky Test Count | Number of tests that intermittently fail | 0 | ![The image is a slide titled "Discovering Pipeline Health" with a list of topics related to pipeline health monitoring, including key metrics, analytics tools, and strategies for handling flaky tests.](https://kodekloud.com/kk-media/image/upload/v1752868143/notes-assets/images/AZ-400-Designing-and-Implementing-Microsoft-DevOps-Solutions-Summary-Maintaining-Pipelines/discovering-pipeline-health-monitoring-topics.jpg) ### Analytics Tools in Azure DevOps * **Azure DevOps Dashboards:** Custom charts and widgets for real-time insights. * **Analytics Views & Widgets:** Prebuilt reports on build trends and test outcomes. * **Azure Test Plans:** * Organize, execute, and track test suites. * Integrates seamlessly with CI/CD to isolate flaky tests. Use Azure Test Plans to tag and quarantine flaky tests. Consistent test results improve confidence in your releases. *** ## 2. Optimizing Pipeline Concurrency Concurrency controls how many jobs or tasks run in parallel. Proper tuning accelerates delivery and reduces costs. ![The image is a presentation slide titled "Optimizing Pipeline Concurrency for Performance and Cost," with a list of topics related to pipeline concurrency, each marked by a colored dot.](https://kodekloud.com/kk-media/image/upload/v1752868145/notes-assets/images/AZ-400-Designing-and-Implementing-Microsoft-DevOps-Solutions-Summary-Maintaining-Pipelines/optimizing-pipeline-concurrency-performance-cost.jpg) ### Concurrency Concepts | Feature | Purpose | Example | | ------------------ | ------------------------------------------------ | --------------------------------------------- | | Parallel Jobs | Run multiple stages or jobs simultaneously | `pool: vmImage: 'ubuntu-latest'` | | Agent Pools | Share agents across teams for better utilization | Create dedicated pools for high-priority jobs | | Concurrency Limits | Prevent overload and control spending | `maxParallel: 4` in YAML | ### Sample YAML Snippet ```yaml theme={null} jobs: - job: Build pool: name: 'Default' demands: - ubuntu strategy: parallel: 3 # Run 3 agents in parallel maxParallel: 3 steps: - script: npm install - script: npm run build ``` Limiting `maxParallel` helps avoid agent contention and unexpected billing spikes. Continually monitor queue times and agent utilization to adjust your concurrency settings. *** ## 3. Migrating Pipelines from Classic to YAML YAML pipelines offer versioning, flexibility, and better collaboration. Follow a structured checklist for a seamless migration. ![The image is a slide titled "Migrating a Pipeline From Classic to YAML in Azure Pipelines," listing topics such as introduction, YAML and classic pipelines, reasons to migrate, a pre-migration checklist, and a step-by-step migration process.](https://kodekloud.com/kk-media/image/upload/v1752868146/notes-assets/images/AZ-400-Designing-and-Implementing-Microsoft-DevOps-Solutions-Summary-Maintaining-Pipelines/migrating-pipeline-classic-to-yaml-azure.jpg) ### Classic vs. YAML Comparison | Aspect | Classic Pipelines | YAML Pipelines | | ------------------ | -------------------- | ------------------------------- | | Definition Storage | GUI-based | Code repository | | Version Control | Limited | Full Git history | | Extensibility | UI Extensions | Custom templates and parameters | | Collaboration | Manual export/import | Pull requests, code reviews | ### Pre-Migration Checklist 1. Inventory existing Classic pipelines and variable groups. 2. Identify custom tasks or extensions. 3. Review environment configurations and security permissions. ### Step-by-Step Migration Process 1. **Create initial YAML file** * Export existing pipeline settings as reference. 2. **Reproduce Classic settings** * Define pools, variables, triggers, and tasks in YAML. 3. **Validate incrementally** * Run small sections of the pipeline using `az pipelines run`. ```yaml theme={null} trigger: branches: include: - main variables: - name: buildConfiguration value: Release jobs: - job: BuildAndTest pool: 'azure-pipelines' steps: - task: DotNetCoreCLI@2 inputs: command: 'build' projects: '**/*.csproj' - task: DotNetCoreCLI@2 inputs: command: 'test' projects: '**/*Tests.csproj' ``` Watch for YAML indentation and syntax errors. A single space can break your pipeline! *** By mastering pipeline health metrics, optimizing concurrency, and migrating Classic to YAML pipelines, you'll be fully prepared for the AZ-400 exam and ready to enhance your organization’s DevOps workflows. ## Links and References * [Azure DevOps Documentation](https://docs.microsoft.com/azure/devops/) * [YAML schema reference](https://docs.microsoft.com/azure/devops/pipelines/yaml-schema) * [Azure Test Plans overview](https://docs.microsoft.com/azure/devops/test/overview)