The `ServerHttpObservationFilter` implementations record observations
for processed HTTP exchanges. The `Observation.Context` contains various
metadata contributed by the observation convention. The instrumentation
can also mark the observation as an error by setting any `Throwable` on
the context.
Because the instrumentation is done as filters, only exceptions reaching
the filter can be considered. Any error handled at a lower level by the
Framework can, or cannot be considered as an error for an observation.
This commit documents how a web application should opt-in for
considering a handled exception as an error for the current observation.
Closes gh-29848
This commit reorganizes the asciidoctor attributes for the reference
documentation. Instead of being contributed partially by the build and
individual documents, attributes are now shared in common files that are
included in top sections.
Rob Winch
Sam Brannen
Brian Clozel