How can you Migrate the web server application to Azure App Service with minimal downtime.

Migrate the web server application to Azure App Service with minimal downtime.

Steps:

1. Preparation :Inventory and assessment: Document the web server configuration, including operating system, application framework, dependencies, and database connections. Assess the application's compatibility with Azure App Service. Refactor code if necessary to ensure smooth operation in the cloud environment. Planning and design: Choose an appropriate App Service plan based on resource requirements (CPU, memory, etc.).Determine storage options for application files and databases (Azure Blob Storage, Azure SQL Database, etc.).Design a migration strategy to minimize downtime, considering options like: Blue-green deployment: Deploy the application to a new environment, test thoroughly, and then switch traffic to the new environment. Rolling update: Gradually update the application instances in the existing environment with the new version. Code modifications: Update configuration files to connect to Azure resources (storage, database) instead of on-premises resources. Implement environment variables to manage configuration differences between development, testing, and production environments.
2. Migration :Package the application: Create a deployment package containing the application code and dependencies according to App Service requirements. you can use the tools like Azure App Service CLI or Azure DevOps pipelines to automate the packaging and deployment process. Deploy to Azure App Service :Deploy the application package to the chosen App Service plan. Configure application settings and environment variables within App Service. Configure continuous integration/continuous delivery (CI/CD) pipeline for future deployments and updates.
3. Testing and Validation :Perform thorough testing of the migrated application in the Azure environment. Validate functionality, performance, and security of the application. Conduct load testing to ensure scalability under high traffic.
4. Cutover and Go-Live :Implement the chosen migration strategy (blue-green deployment or rolling update) to switch traffic to the migrated application in the new environment. Monitor the application health and performance closely after go-live.
5. Post-Migration (Ongoing: Decommission the on-premises server after successful migration and verification. Leverage Azure monitoring and logging tools to track application performance and troubleshoot any issues. Update the migrated application and deploy new features through the established CI/CD pipeline.