Struct OtelMetrics 

pub struct OtelMetrics { /* private fields */ }

A Metrics implementation backed by OpenTelemetry instruments.

Records the following instruments:

Instrument	Kind	Unit	Description
rpc.server.call.duration	Histogram	s	Every inbound call, per the semantic conventions
a2a.server.requests	Counter	request	Total inbound requests
a2a.server.responses	Counter	response	Total outbound responses
a2a.server.errors	Counter	error	Total errors
a2a.server.latency	Histogram	s	Request latency in seconds
a2a.server.queue_depth	Gauge	queue	Number of active event queues
a2a.server.persistence_errors	Counter	error	Task writes that failed
a2a.server.push_deliveries	Counter	delivery	Push attempts, by outcome
a2a.server.pool.active	Gauge	connection	Active (in-use) connections
a2a.server.pool.idle	Gauge	connection	Idle connections
a2a.server.pool.created	Counter	connection	Total connections created
a2a.server.pool.closed	Counter	connection	Connections closed

rpc.server.call.duration carries rpc.system.name, rpc.method, rpc.status_code and, on failure, error.type (see RpcCall). The a2a.server.* counters and histogram carry a method attribute; the error counter additionally carries an error attribute. Both histograms use the conventions’ advisory buckets (RPC_DURATION_BUCKETS).

Implementations

impl OtelMetrics

pub fn from_meter(meter: &Meter) -> Self

Create an OtelMetrics from an already-configured Meter.

Prefer OtelMetricsBuilder for typical usage.

Trait Implementations

impl Debug for OtelMetrics

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Metrics for OtelMetrics

fn on_request(&self, method: &str)

Called when a request is received, before processing.

fn on_response(&self, method: &str)

Called when a response is successfully sent.

fn on_error(&self, method: &str, error: &str)

Called when a request results in an error.

fn on_latency(&self, method: &str, duration: Duration)

Called when a request completes (successfully or not) with the wall-clock duration from receipt to response.

fn on_queue_depth_change(&self, active_queues: usize)

Called when the number of active event queues changes.

fn on_persistence_error(&self, operation: &str, error_kind: &str)

Called when the background event processor fails to persist a task.

fn on_push_delivery(&self, outcome: &str)

Called after each attempt to deliver a push notification.

fn on_connection_pool_stats(&self, stats: &ConnectionPoolStats)

Called with connection pool statistics when available.

fn on_rpc_call(&self, call: &RpcCall<'_>)

Called once per inbound A2A call, on every binding, when it finishes — with what the OpenTelemetry semantic conventions’ rpc.server.call.duration records. See RpcCall.