Observing real user activity
Observability is an essential ingredient for understanding the performance of a system. We must be able to see the inner workings of every part of the system so that we can assess the health of the system and identify the root cause of any issues. Traditionally, we have focused on monitoring the backend services and servers. However, a significant portion of today's application logic executes on the frontend within a user's browser on their own devices.
Leveraging the processing power of the user's device allows us to spread out the load and dramatically improve the scalability of a system. However, it also makes it more difficult to monitor the behavior of the system, since we have to capture information from many devices. To address this problem, we need Real User Monitoring (RUM) and synthetic transactions.
RUM
RUM encompasses the set of tools we use to observe the performance of the frontend application logic. This includes sampling...