What aspect of APM allows for performance monitoring across distributed applications?

Distributed tracing is the aspect of Application Performance Monitoring (APM) that enables performance monitoring across distributed applications. This technique allows you to track the flow of requests through various services and components of a distributed system. By attaching unique identifiers to requests, you can see how they traverse through different microservices, how long each step takes, and where bottlenecks may occur.

This visibility is essential for understanding the performance of complex, distributed architectures, as it helps identify latency issues and performance degradation that may not be evident when looking at individual services in isolation. Distributed tracing provides insights into the entire transaction lifecycle, making it easier to diagnose issues and optimize performance across the entire application stack.

While transaction monitoring focuses on capturing metrics related to specific transactions, real user analytics centers around the actual end-user experience, and log management pertains to the collection and analysis of log data from various sources, these aspects do not inherently provide the same level of detailed insight into the interactions between distributed components that distributed tracing does.