While test-driven development and QA practices improve code quality and provide confidence in the application, when a system fails, developers and system administrators need contextual information about its execution.

• 虽然测试驱动的开发和QA手段可以提高代码质量并增强对应用程序的信心,但是当某个系统失败时,开发人员和系统管理员需要了解系统的相关执行上下文信息。