Struct EndpointTelemetryLayer 

pub struct EndpointTelemetryLayer { /* private fields */ }

Emit telemetry about the status of HTTP transactions.

This layer can be used with services that deal with http::Request and http::Response, and wraps them to provide telemetry about the status of an HTTP “transaction”: a full round-trip of request and response.

Metrics

The following metrics are emitted:

• network_http_requests_failed_total: The total number of HTTP requests that failed with a status code of 400, 403, or 413.
• network_http_requests_success_total: The total number of successful HTTP requests. (any response with a non-4xx/5xx status code)
• network_http_requests_success_sent_bytes_total: The total number of body bytes sent in successful HTTP requests. (see note below on how this is calculated)
• network_http_requests_errors_total: The total number of HTTP requests that had an error, either during the sending of the request or in the response. This is further broken down by the error_type label.
  • For all responses with a status code greater than 400, error_type will be client_error and code will be a stringified version of the status code.
  • When there is an error during the sending of the request, error_type will be send_failed.

All metrics are emitted with two base tags:

• domain: The full domain of the request, including scheme and port, but excluding any credentials.
• endpoint: The endpoint name, which is derived from the URI path by default but can be customized. (See EndpointTelemetryLayer::with_endpoint_name_fn for information on customization and how the endpoint name, overall, is sanitized.)

Success bytes calculation

We calculate the number of bytes sent by examining the body length itself, which is done via Body::size_hint. This requires that an exact body size is known, which is not always the case. If the body size is not known, this metric will not be emitted on a successful response.

For common body types, like FrozenChunkedBytesBuffer, the size hint is always exact and so this functionality should work as intended.

Implementations

impl EndpointTelemetryLayer

pub fn with_metrics_builder(self, builder: MetricsBuilder) -> Self

Create a new EndpointTelemetryLayer with the given ComponentContext.

The component context is used when creating metrics, which ensures they are tagged in a consistent way that attributes the metrics to the component issuing the HTTP requests.

pub fn with_endpoint_name_fn<F>(self, endpoint_name_fn: F) -> Self

where F: Fn(&Uri) -> Option<MetaString> + Send + Sync + 'static,

Sets the function used to extract the “endpoint name” from a URI.

The value returned by this function will be sanitized to ensure it can be used as a tag value, and is limited to: ASCII alphanumerics, hyphens, underscores, slashes, and periods. Any non-conforming character will be replaced with an underscore. Characters will be converted to lowercase.

The value returned by this function is also cached for the given URI, and so the function should not rely on non-deterministic behavior, or state, that could change the generated endpoint name for subsequent calls with the same input URI.

Trait Implementations

impl Clone for EndpointTelemetryLayer

fn clone(&self) -> EndpointTelemetryLayer

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Default for EndpointTelemetryLayer

fn default() -> EndpointTelemetryLayer

Returns the “default value” for a type.

impl<S> Layer<S> for EndpointTelemetryLayer

type Service = EndpointTelemetry<S>

The wrapped service

fn layer(&self, service: S) -> Self::Service

Wrap the given service with the middleware, returning a new service that has been decorated with the middleware.