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Monitor applications end to end

From Start to Finish

Article from ADMIN 85/2025

By Tim Schürmann

Your web server is running perfectly according to Nagios, but is it delivering the intended user experience? End-to-end monitoring lets you know whether your application is performing as expected.

All of your systems seem to be working normally, but virtually nobody has placed an order in the online store since yesterday afternoon. A painstaking manual investigation reveals that the shopping cart takes an agonizingly long time to redirect to checkout – the problem is caused by a messed up cache. Nasty bugs like this can quickly cause expensive damage, but they often slip through the fingers of classic monitoring solutions because they only check whether the web server and PHP are running, not whether the web application being served to your customers is still working correctly and, above all, smoothly. For this problem, you need a special monitoring system.

The right solution will check all of your real users as they fill the shopping cart and check out. Alternatively, or additionally, it will slip into the role of a real customer and call up critical functions on a regular basis. For example, the monitoring system could run through a complete ordering process in the online store or register as an author in a blog. In each case, the tool then records the time it takes to complete the action. In this way, you find out whether your responsive design for smartphones is accidentally concealing important controls and whether logging into the online store is suddenly taking several minutes to complete.

In contrast to traditional infrastructure or system monitoring, these tools continuously monitor software quality from the user's perspective. The monitoring tools automatically check all of the components involved in the background, from the database to the user interface at the other end. This process is called end-to-end (E2E) monitoring (Figure 1) and is primarily used for web applications (see the "Confusion of Terms" box). However, it can also be used for native Linux programs and smartphone apps. E2E monitoring is even suitable for applications that do not have a graphical user

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