Almost everyone has monitoring. In the ideal world it is a reliable tool that detects sympthoms earlier than they become serious problems. Often time APM on a free plan with out-of-the-box reports is used as a monitoring tool. As a result, something is measured, some alerts are sent into the chat, no one responds to them, and one day the major incident happens.

In the talk we will:

- define monitoring antipatterns;

- pick the most critical metrics and ways to see insights in charts;

- represent the system in the terminology of queue theory;

- figure out how to choose lower–level metrics and how to use them to find problems;

- discuss why alerts are helpful, and when they are not needed.