Module telemetry 

Client metrics push (KIP-714).

When Kafka’s enable.metrics.push is on (the default), a producer, consumer or admin client asks a broker for its client metrics subscription with GetTelemetrySubscriptions, and pushes the metrics that the subscription names with PushTelemetry at the push interval. On close it sends one last push with terminating set.

ClientTelemetry is that reporter, as Kafka’s ClientTelemetryReporter and the telemetry sender of its NetworkClient are. A Client built with ClientTelemetryConfig starts one. The metrics come from a ClientMetrics registry; client-core registers the network metrics of Kafka’s Selector in it.

Differences from Kafka:

• The reporter sends on a connection that the client already has open. It does not open a connection of its own, so a client that has no open connection pushes nothing until it opens one.
• A subscription with the zero client instance id stops telemetry. Kafka’s reporter throws from its response handler, after which it sends no further request.

Modules

otlp

The part of the OpenTelemetry metrics protocol (OTLP) that a KIP-714 client pushes.

Structs

ClientMetrics

The metric registry of one client. A clone shares the registry.

ClientTelemetry

A running KIP-714 reporter. Dropping it starts the close, as close does, without the wait.

ClientTelemetryConfig

What a client pushes: its type and the resource attributes of every metric (ClientTelemetryProvider.contextChange).

Counter

A monotonic counter, pushed as an OTLP sum (Kafka’s CumulativeSum and WindowedCount).

Gauge

A value that goes up and down, pushed as an OTLP gauge.

MetricKey

The name and attributes of one metric, as KIP-714 names them.

NetworkMetrics

The network metrics of a client’s connections: the -total metrics of Kafka’s Selector in the client’s metric group, and its connection-count.

TelemetryTiming

The timing of a reporter.

Enums

TelemetryClientType

The kind of client, which names its metric group.

Constants

TELEMETRY_METRIC_DOMAIN

The prefix of every client metric name (ClientTelemetryProvider.DOMAIN).

Traits

TelemetryConnections

The connections that a reporter sends on.

Functions

client_instance_id

Kafka’s clientInstanceId of a producer, consumer or admin client (ClientTelemetryUtils.fetchClientInstanceId).