Spring Cloud Sleuth instruments all your Spring application
automatically, so you shouldn’t have to do anything to activate
it. The instrumentation is added using a variety of technologies
according to the stack that is available, e.g. for a servlet web
application we use a
Filter, and for Spring Integration we use
You can customize the keys used in span tags. To limit the volume of
span data, by default an HTTP request will be tagged only with a
handful of metadata like the status code, host and URL. You can add
request headers by configuring
list of header names).
Remember that tags are only collected and exported if there is a
Currently the instrumentation in Spring Cloud Sleuth is eager - it means that we’re actively trying to pass the tracing context between threads. Also timing events are captured even when sleuth isn’t exporting data to a tracing system. This approach may change in the future towards being lazy on this matter.