The core issue is a functional defect (a memory leak) introduced by a "small change" to existing code. Regression testing is the specific process of re-running functional and non-functional tests to ensure that previously developed and tested software still performs correctly after a change. An effective regression test suite for a critical resource allocation module would include performance and memory profiling tests. Executing this suite after the change would have detected the memory leak before deployment, thus preventing the production failure. This makes it the most efficient and direct technique to prevent this specific problem from reoccurring.

A. Load: While a load test would have exposed this specific memory leak, regression testing is the overarching process that ensures any bug introduced by a change is caught.

B. Smoke: Smoke testing is a preliminary, high-level check to ensure basic functionality works; it is not deep enough to detect subtle resource management bugs like a memory leak.

D. Canary: Canary testing is a deployment strategy that exposes new code to a small subset of users. It mitigates production impact but does not prevent the bug from being deployed.

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1. Ammann

P.

& Offutt

J. (2016). Introduction to Software Testing (2nd ed.). Cambridge University Press. In Chapter 1

Section 1.2

"A Fault

Error

Failure Terminology

" the text defines regression testing as "the process of retesting a modified program to ensure that no new faults have been introduced as a result of the changes." This directly aligns with the scenario where a change introduced a fault.

2. Bertolino

A. (2007). Software Testing Research: Achievements

Challenges

Dreams. In 2007 Future of Software Engineering (pp. 85-103). IEEE. https://doi.org/10.1109/FOSE.2007.27. On page 91

the paper discusses regression testing as essential for software evolution

stating its goal is to "provide confidence that the changes did not break any previously working functionality."

3. National Institute of Standards and Technology (NIST). (2022). Secure Software Development Framework (SSDF) Version 1.1: Recommendations for Mitigating the Risk of Software Vulnerabilities (NIST Special Publication 800-218). Section 4

Practice PW.8

"Test Executable Code

" emphasizes the need to "review test plans and test results to confirm that the tests adequately address all security requirements." A comprehensive test plan

subject to regression

would include tests for resource exhaustion vulnerabilities like memory leaks.