Spring Cloud Sleuth
- distributed tracing solution for Spring Cloud
- Basic unit of work
- identified by a unique 64-bit ID for the span and another 64-bit ID for the trace the span is a part of
- Spans also have other data, such as descriptions, timestamped events, key-value annotations (tags), the ID of the span that caused them, and process IDs (normally IP addresses).
- A set of spans forming a tree-like structure