Real user monitoring (RUM) is a passive monitoring technology that records all user interaction with a website or client interacting with a server or cloud-based application. Monitoring actual user interaction with a website or an application is important to operators to determine if users are being served quickly and without errors and, if not, which part of a business process is failing. Software as a service (SaaS) and application service providers (ASP) use RUM to monitor and manage service quality delivered to their clients. Real user monitoring data is used to determine the actual service-level quality delivered to end-users and to detect errors or slowdowns on web sites. The data may also be used to determine if changes that are promulgated to sites have the intended effect or cause errors.
Organizations also use RUM to test website or application changes prior to deployment by monitoring for errors or slowdowns in the pre-deployment phase. They may also use it to test changes within the production environment, or to anticipate behavioural changes in a website or application. For example, a website may add an area where users could congregate before moving forward in a group (for example, test-takers that log into a website individually over a period of twenty minutes and that then simultaneously begin taking a test), this is called rendezvous in test environments. Changes to websites such as these can be tested with RUM. As technology shifts more and more to hybrid environments like cloud, fat clients, widgets, and apps, it becomes more and more important to monitor from within the client itself.
Real user monitoring is typically "passive monitoring", i.e., the RUM device collects web traffic without having any effect on the operation of the site. In some limited cases, it also uses JavaScript injected into a page or native code within applications to provide feedback from the browser or client. This is also referred to as Real-time Application Monitoring that focuses on the End-User Experience (EUE) and is a key component in the application performance management technology space.
Passive monitoring can be very helpful in troubleshooting performance problems once they have occurred. Passive monitoring differs from synthetic monitoring with automated web browsers in that it relies on actual inbound and outbound web traffic to take measurements.