A Business Transaction must be defined when a discovered entry point initiates one or more asynchronous activities. The Business Transaction establishes the logical monitoring context for the original user request and enables AppDynamics to associate subsequently spawned asynchronous work with that request.
When asynchronous processing occurs, execution may continue on different threads, task executors, queues, or callback mechanisms after the initiating thread has completed or moved on. AppDynamics propagates the Business Transaction correlation context across these asynchronous boundaries so the resulting activity can be represented as part of the same end-to-end transaction. This allows the analyst to evaluate total response time, asynchronous segments, downstream calls, errors, and call-graph execution in the proper transaction context.
A Custom Endpoint is not required merely because asynchronous work is spawned. Asynchronous metrics and endpoint metrics are measurements generated from monitoring; they do not establish the identity or correlation boundary of the request.
Relevant CAAPA Study Guide topics include Business Transaction Discovery, Entry Points, Asynchronous Transaction Tracking, Thread Handoffs, Transaction Correlation, Call Graphs, and End-to-End Transaction Visibility.