Stresstesting

Stress testing, sometimes written as stresstesting, is a type of non-functional software testing designed to evaluate a system beyond normal operational capacity, often to a breaking point, in order to observe how it fails and recovers. The primary goals are to identify the system's robustness, stability under high load, performance limits, failure modes, and recovery behavior, as well as data integrity under stress. Stress testing contrasts with load testing, which tests under expected peak loads, and scalability testing, which assesses how well the system scales with increasing resources or workload.

Approach: stress tests are planned with specific thresholds and end conditions, such as maximum concurrent users, requests per second, or transaction volume. Test scenarios may include sudden spikes, sustained high load (soak), or gradual degradation. Metrics collected typically include response time, error rate, throughput, resource utilization (CPU, memory, disk I/O, network), and system latency. Monitoring and logging are essential to identify bottlenecks, memory leaks, thread exhaustion, or failover issues.

Process: define objectives and exit criteria, prepare a staging or test environment, create repeatable test scripts, execute tests, monitor, analyze results, and document failure points and recommended mitigations. Safety measures are important to avoid impacting production systems, and tests should be designed to fail gracefully and recover.

Common domains include web applications, APIs, databases, distributed systems, and hardware-in-the-loop environments. Tools such as JMeter, Locust, Gatling, LoadRunner, and commercial solutions support stress testing through automated scenarios.