On which tool for running tests did you check the operation of multithreaded system components?

Tools used for testing multithreaded components often include those that allow running parallel tests and monitoring thread states. Among popular tools:

• JUnit with extensions for multithreading (for example, JUnit5 supports parallel test execution).
• TestNG — supports parallel test execution and grouping.
• Thread Weaver — a library for testing multithreaded Java programs.
• Concurrency Testing Tools: such as IBM Concurrency Testing Tool, which help identify synchronization issues.

In QA Automation, the following are often used:

• JMeter — for load testing with multithreaded scenarios.
• Gatling — for load testing with support for asynchronous requests.

Example of using JUnit5 for parallel test execution:

@Test
@Execution(ExecutionMode.CONCURRENT)
void testConcurrentProcessing() {
    // test code
}

Thus, the choice of tool depends on the goals: functional testing of multithreading or load testing.