Cloud computing has become a vital part of modern IT infrastructure, offering flexibility, scalability, and cost-effectiveness. As organizations increasingly move from on-premises infrastructure to cloud environments, it is crucial to ensure that this migration process doesn’t introduce new issues or degrade the performance of existing systems. This article delves into cloud migration testing, discussing key aspects, testing strategies, challenges, and examples that illustrate why a well-planned migration test strategy is essential.

Key Terminology

What is Cloud?
The cloud refers to a network of remote servers hosted on the internet, which store, manage, and process data. Services such as Amazon Web Services (AWS), Microsoft Azure, and Google Cloud Platform (GCP) provide on-demand computing resources. These services help companies scale their IT needs based on demand without managing physical hardware.

What is On-Premise?
On-premise, popularly known as on-prem, refers to software and hardware located physically within an organization’s premises. In traditional setups, companies maintain their own servers, networks, and storage infrastructure, often requiring high maintenance and operational costs.

What is Cloud Migration?
Cloud migration is the process of moving data, applications, and workloads from on-premises environments to cloud environments. Depending on the migration strategy, this could involve either moving applications as-is (known as lift-and-shift) or optimizing them for the cloud.

What gets migrated?
During cloud migration, several critical components can be moved from on-premises environments to cloud infrastructures. Understanding these components and their significance helps ensure a smooth transition and optimal performance in the new environment.

The main categories of migration include:

Applications
Applications are at the core of most migration efforts. This category encompasses both front-end and back-end systems.

Front-End Applications: These are the client-facing interfaces and user-side components that users interact with. For instance, a web application like an online banking system includes a website interface that customers use to check their balances, transfer funds, and manage their accounts.
Back-End Systems: These components handle the application’s logic, database interactions, and business rules. They are typically less visible to users but are crucial for application functionality. For example, the server-side application that processes transactions, interacts with the database to retrieve user information, and ensures that all data is handled correctly.

Example: Consider a retail company that has an online shopping platform. During migration, the entire application stack, including the front-end (the shopping cart interface, product pages, and user account sections) and back-end services (order processing, inventory management, and payment processing), is migrated to a cloud environment like AWS or Azure.

Data
Data is a critical component of cloud migration, including various types of information stored within the organization’s systems. This can include:

Databases: Structured data stored in relational databases, such as customer information, transaction records, and product inventories. For instance, a MySQL database containing customer profiles, orders, and product details would be migrated to a cloud database service like Amazon RDS or Azure SQL Database.

Logs: System logs that capture activity, errors, and user interactions. These logs are vital for troubleshooting and monitoring system performance. For example, an application might generate logs for every user action, such as logging in, making purchases, or generating reports.

User-Generated Content: Any content created by users, such as comments, product reviews, or uploaded images. For a social media platform, this could mean migrating all user posts, likes, and shares to the cloud.

Example: In the case of a cloud-based photo-sharing application, the migration process would involve transferring large volumes of user-uploaded photos and metadata (like titles, descriptions, and tags) from local servers to a cloud storage solution like Amazon S3. This allows for scalable storage and easy access for users across the globe.

Infrastructure
Infrastructure includes all the hardware and software components that support the applications and data. This involves:

Servers: Physical or virtual machines that host applications and data. Migrating these servers involves moving them to cloud-based services like AWS EC2 instances or Azure Virtual Machines, which provide scalable computing resources.

Storage: Data storage solutions, such as file systems, databases, and object storage. For example, migrating on-premises file storage (like shared drives) to cloud storage solutions like Google Drive or Azure Blob Storage ensures data is accessible and protected.

Networking: The network configuration that allows different components of the application to communicate with each other. This could include setting up virtual private clouds (VPCs), subnets, and firewalls in the cloud environment to mirror the on-prem network setup.

Security Configurations: Security measures such as firewalls, encryption protocols, and access controls are crucial for protecting data and applications in the cloud. Ensuring these configurations are correctly implemented in the new environment is vital to maintain security standards.

Example: A company running a customer relationship management (CRM) system on-prem may migrate its entire IT infrastructure, including servers that host the CRM software, databases storing customer data, and networking configurations that connect various components. After migration to a cloud service, the CRM becomes accessible via the internet, allowing remote teams to access customer information and collaborate more efficiently.

What to Test in Cloud Migration

Cloud migration testing is essential to verify that all components of the system work as expected post-migration. Key areas to test include:

Smoke Testing the Front-End Application

Smoke tests ensure that the basic functionality of the front-end works after migration. This includes verifying:

• Access to the Application: Can users still reach the application via the correct URL?
• UI Rendering: Are all UI elements loading and displaying correctly?
• User Actions: Can users perform core tasks like logging in or submitting forms?

Example: If you migrate a healthcare portal, a smoke test would check whether doctors can log in to view patient records and whether patients can schedule appointments.

Database Migration Testing

Database testing ensures the integrity of data after migration. Key points include:

• Table and Row Counts: Ensure that the number of tables and rows match pre-migration counts.

Example: If your on-prem database has 50 tables, the cloud-based database should have the same. You can verify that each table has the same number of rows pre- and post-migration.

• Stored Procedures: Ensure stored procedures still function correctly after the migration.

Example: In an e-commerce platform, if you have a stored procedure for calculating discounts based on user profiles, you should verify that it works as expected after migration.

Data Integrity: Ensure that no data is lost or corrupted during migration.

• Testing Across Various Environments
• Testing across development, staging, and production environments is crucial to avoid environment-specific issues.

Example: During migration, ensure that the configuration settings (like database connection strings or API endpoints) are correct in each environment.

Running Automation Suite
Running an existing automation suite after migration helps catch functional bugs that could arise from the new infrastructure. The automation suite configurations should be updated to point to the cloud environment.

Example: If your suite includes tests for checking the login process, ensure that it still works after pointing to the cloud-based database.

Integration with Third-Party Systems
If your application integrates with third-party services (such as payment gateways, authentication providers, or CRM tools), testing those integrations is critical.

Example: If an application uses an external payment gateway, after migration, ensure that transactions still go through and are recorded correctly.

Non-Functional Testing
Non-functional testing focuses on the performance, scalability, and security aspects of the application after migration.

Performance Testing
API Response Times: Measure how quickly APIs respond in the cloud environment compared to on-prem.
Example: If an API call to fetch a user’s order history takes 500ms on-prem but 1.5 seconds after migration, it signals a performance issue that needs investigation.

Application Load Testing: Assess how the application handles increased load in the cloud.

Example: A web application designed to handle 1,000 users concurrently may need to be tested for 5,000 users in the cloud to verify that auto-scaling features work.

Security Testing
Ensure that security protocols such as encryption, access controls, and certificates are in place post-migration.

Example: An application using HTTPS on-prem should ensure that SSL certificates are correctly configured and renewed in the cloud.

Cloud Migration Testing Approaches

Different migration strategies require different testing approaches:

Lift and Shift

This strategy involves migrating the application without significant architectural modifications. Testing should ensure that the application functions the same way it did in its on-prem environment.

Example: A financial firm might move their accounting software to the cloud without changing its architecture. The testing would primarily focus on ensuring that transactions, calculations, and reports are generated correctly.

Lift and Optimize

Here, applications are modified to take advantage of cloud-native features like auto scaling and serverless functions. Testing should focus on both the functional aspects and new features.

Example: An e-commerce platform may migrate to the cloud and then refactor its application to use serverless functions for order processing. Testing should verify that the new architecture scales effectively under load and that all order-related functionalities work seamlessly.

Partial Migration

In partial migration, some sections of the application remain on-premises while others move to the cloud. This requires thorough testing to ensure both environments interact correctly.

Example: A hybrid architecture where customer-facing applications are in the cloud while sensitive data remains on-premises due to compliance regulations. Testing must confirm that the two environments can communicate effectively, especially for data transfers and user sessions.

Verifying Success Post-Migration

Once migration testing is complete, organizations should verify that the application meets the expected performance and functional criteria. Key steps include:

• User Acceptance Testing (UAT): Involve end-users to validate that the application meets their needs and expectations.
• Monitoring Post-Migration: Implement monitoring solutions to track application performance, user interactions, and system health in the cloud environment.

Cloud Testing Infrastructure

A robust cloud testing infrastructure is essential for effective testing. It typically includes

Cloud-Based Test Environments: Set up testing environments that mirror production settings to ensure accurate testing outcomes.

Test Automation Tools: Leverage cloud-based testing tools for continuous integration/continuous deployment (CI/CD) pipelines to facilitate regular testing during and after migration.

Testing Across Clouds
If migrating between different cloud providers, it’s crucial to validate compatibility and functionality across different cloud services.

Example: Moving an application from AWS to Azure may require testing for API compatibility, performance differences, and data handling between the two platforms.

Benefits and Risks of Cloud Migration Testing

Benefits

• Enhanced Performance: Identifying and addressing performance issues before they impact users can enhance the overall user experience.
• Reduced Downtime: Effective migration testing helps minimize application downtime during migration, ensuring business continuity.
• Increased Confidence: Thorough testing provides stakeholders with confidence that the migration will meet business goals.

Risks

• Data Loss: Insufficient testing can lead to data loss during migration.
• Downtime: Unforeseen issues can cause application downtime, affecting user access and business operations.

• Incompatibility Issues: Applications may not work as expected in the new cloud environment if compatibility isn’t thoroughly tested.

Challenges in Cloud Migration Testing

• Legacy Systems: Testing older systems that may not be compatible with cloud environments can be challenging and may require additional effort.

Example: A manufacturing company relying on a legacy ERP system may face difficulties migrating data due to outdated technologies.

Operational Changes: Organizations may need to adapt to new operational processes in the cloud, which can complicate testing efforts.

Conclusion

Cloud migration is a critical process that requires careful planning and testing to ensure success. By understanding what to test, adopting appropriate testing strategies, and addressing the associated challenges, organizations can achieve a seamless transition to the cloud. With thorough testing, businesses can leverage the full benefits of cloud computing while minimizing risks, ensuring that their applications and data remain secure, accessible, and high-performing.

Source: This blog was originally published at testgrid.io