What does proactive monitoring involve in the context of web applications?

Proactive monitoring in the context of web applications is fundamentally about taking preemptive actions to ensure the security and functionality of the application before issues arise. The correct approach involves having external agents run scripted transactions, which is related to continuously testing the application under various scenarios as it operates in a production environment. This helps identify potential vulnerabilities and performance issues before they can be exploited or lead to downtime.

By using scripted transactions, organizations can simulate real user interactions and continuously validate the application’s security posture and functionality. This ongoing monitoring can catch problems early on, noticeably enhancing the application's resilience against attacks or errors that users might encounter.

Other methods, while still important, focus more on specific aspects of application security or operations rather than encompassing a comprehensive, continuous approach like proactive monitoring does. For instance, running manual tests on user input mainly focuses on specific vulnerabilities rather than ongoing systemic checks, while analyzing code for vulnerabilities emphasizes static analysis rather than dynamic performance. Implementing firewall rules addresses network security but does not directly relate to monitoring the application's functionality. Thus, scripted transactions effectively embody proactive monitoring's intent to safeguard applications in a dynamic environment.