Module metrics 

The Kafka metrics framework (org.apache.kafka.common.metrics).

Faithful translation of the Java metrics core: same class names, file-per- class, identical metric values / names / recording-level gating. Java’s synchronized is mapped to the minimal Rust atomic/lock equivalent (atomics for pure-counter stats, Mutex where multi-field mutation needs it). JMX is replaced by the MetricsReporter trait seam.

Re-exports

pub use gauge::Gauge;

pub use metric_value_provider::MetricValueProvider;

pub use sensor::RecordingLevel;

pub use sensor::Sensor;

Modules

gauge

A gauge metric is an instantaneous reading of a particular value (org.apache.kafka.common.metrics.Gauge).

metric_value_provider

Super-interface for Measurable or Gauge that provides metric values (org.apache.kafka.common.metrics.MetricValueProvider).

sensor

A sensor applies a continuous sequence of numerical values to a set of associated metrics (org.apache.kafka.common.metrics.Sensor).

stats

Concrete statistics (org.apache.kafka.common.metrics.stats).

Structs

ClosureMeasurable

A Measurable backed by a closure, mirroring Java’s functional-interface usage of Measurable (e.g. (config, now) -> TimeUnit.SECONDS.convert(...) in KafkaConsumerMetrics / HeartbeatMetricsManager). The symmetric counterpart of crate::common::metrics::gauge::new.

KafkaMetric

A metric tracked by the registry. Holds a MetricName, a (mutable) MetricConfig and a MetricValueProvider.

MetricConfig

Configuration values for metrics.

Metrics

A registry of sensors and metrics.

MetricsView

A live, read-only view of the metrics of a client, indexed by metric name: what Java’s clients return from metrics() as Collections.unmodifiableMap(metrics.metrics()).

NamedMeasurable

A named Measurable child of a CompoundStat.

Quota

An upper or lower bound for metrics.

QuotaViolationError

Thrown when a sensor records a value that causes a metric to go outside the bounds configured as its quota

SensorOptions

The parameters of Metrics::sensor_with_options.

SensorOptionsBuilder

Fluent builder for SensorOptions.

Enums

TimeUnit

A subset of java.util.concurrent.TimeUnit used by the metrics rate stats.

Traits

CompoundStat

A compound stat is a stat where a single measurement and associated data structure feeds many metrics. This is the example for a histogram which has many associated percentiles.

Measurable

A measurable quantity that can be registered as a metric.

MeasurableStat

A MeasurableStat is a Stat that is also Measurable (i.e. can produce a single floating point value). This is the interface used for most of the simple statistics such as Avg, Max, CumulativeCount, etc.

MetricsReporter

A plugin interface to allow things to listen as new metrics are created so they can be reported.

Stat

A Stat is a quantity such as average, max, etc that is computed off the stream of updates to a sensor.