Recovery testing is a type of software testing that aims to verify how well a system can recover from a failure or a system crash. Recovery testing is important for ensuring the quality and reliability of a system, especially for mission-critical applications that require High Availability(HA) and Fault Tolerance. Recovery testing can be performed in different ways, depending on the type and severity of the failure scenario. It is also known as reliability testing.
How to Perform
To perform Recovery Testing, the tester needs to simulate a failure condition and observe how the system reacts. The tester should also verify that the system meets the following criteria after the recovery:
- The system resumes its normal operation without any errors or warnings
- The system does not lose any data or functionality due to the failure
- The system does not compromise its security or reliability due to the failure
- The system does not exhibit any negative effects on its performance or usability due to the failure
Types of Recovery Testing
Some types of recovery testing are as follows:
- System Crash
- Hardware Failure
- Software Failure
- Network Failure
- Database Recovery
- Power Failure
- Data corruption
This type of testing involves intentionally crashing or terminating critical components of the system, such as software applications or servers, to see how the system responds and whether it can recover without data loss. For example, abruptly shutting down a database server and then restarting it to ensure data integrity and system stability.
Hardware components, like hard drives, memory modules, or network devices, can fail unexpectedly. Recovery testing may include testing how the system handles hardware failures, such as replacing a faulty hard drive in a RAID array or failing over to a redundant network switch.
In this type of testing, testers intentionally trigger software failures, such as crashing an application, to see how well the system can recover. This helps ensure that software components can restart gracefully without data corruption.
Network failures, like disconnections, packet loss, or network equipment failures, can disrupt communication between system components. Recovery testing assesses how the system handles these network failures and whether it can reestablish communication without loss of data.
Power outages can disrupt system operations. Recovery testing in this context may involve sudden power cuts to assess how uninterruptible power supplies (UPS) and backup generators handle these situations.
Databases are critical components of many applications. Database recovery testing involves simulating database failures and testing how the system can restore data consistency and integrity, often by replaying transaction logs or restoring from backups.
Data corruption can occur due to various reasons, such as software bugs or hardware failures. Recovery testing ensures that the system can detect and repair corrupted data to maintain data integrity.
Systems with load balancers or failover mechanisms are tested to ensure that when one server or component fails, traffic is redirected to healthy servers, and the system continues to function seamlessly. This is essential for high availability.
Business Continuity & Disaster Recovery (BC/DR)
BC/DR testing encompasses a broader scope of recovery testing, involving the entire business processes and infrastructure. It aims to ensure that a business can continue operations in the face of disasters, such as natural disasters or large-scale system failures.
Recovery Testing is a valuable technique to ensure the quality and resilience of a software system. It can help improve user satisfaction and trust in the system, as well as reduce the costs and risks associated with system failures.