Server middleware to record metrics for the http4s server.
This middleware will record: - Number of active requests - Time duration to send the response headers - Time duration to send the whole response body - Time duration of errors and other abnormal terminations
This middleware can be extended to support any metrics ecosystem by implementing the org.http4s.metrics.MetricsOps type
Same as apply, but can classify requests effectually, e.g. performing side-effects. Failed attempt to classify the request (e.g. failing with F.raiseError) leads to not recording metrics for that request.
Value parameters
classifierF
a function that allows to add a classifier that can be customized per request
emptyResponseHandler
an optional http status to be registered for requests that do not match
errorResponseHandler
a function that maps a java.lang.Throwable to an optional http status code to register
ops
a algebra describing the metrics operations
Attributes
Returns
the metrics middleware
Note
Compiling the request body in classifierF is unsafe, unless you are using some caching middleware.