What is created by Dynatrace when it detects a call to a span attachment?

When Dynatrace detects a call to a span attachment, it creates a default service. This occurs as part of its automated monitoring capabilities. The default service acts as a representation of the newly discovered service interaction that is being monitored. This helps in tracing the lifecycle of requests, tracking dependencies, and visualizing the service architecture effectively.

The creation of a default service allows Dynatrace to collect key metrics around performance, availability, and user experience associated with that service. This automatic detection enhances observability, enabling teams to respond quickly to any performance issues or anomalies and understand the behavior of their applications in a microservices architecture.

In contrast, the other options represent different components or organizational structures that might be part of a monitoring setup, but they do not directly relate to the immediate action Dynatrace takes upon detecting span attachment calls. Custom endpoints, service groups, and microservice nodes are more specific constructs that may come into play later depending on the application's architecture and monitoring strategy. However, a default service is created as the foundational unit in response to span calls, facilitating immediate monitoring and analysis.