org.apache.calcite.avatica.metrics

Interface MetricsSystem

All Known Implementing Classes:

DropwizardMetricsSystem, NoopMetricsSystem

public interface MetricsSystem

General purpose factory for creating various metrics. Modeled off of the Dropwizard Metrics API.

Method Summary

Modifier and Type	Method and Description
Counter	getCounter(String name) Get or construct a Counter used to track a mutable number.
Histogram	getHistogram(String name) Get or construct a Histogram used to measure a distribution of values.
Meter	getMeter(String name) Get or construct a Meter used to measure durations and report distributions (a combination of a Timer and a Histogram.
Timer	getTimer(String name) Get or construct a Timer used to measure durations and report rates.
<T> void	register(String name, Gauge<T> gauge) Register a Gauge.

Method Detail

getTimer

Timer getTimer(String name)

Get or construct a Timer used to measure durations and report rates.

Parameters:

name - The name of the Timer.

Returns:

An instance of Timer.

getHistogram

Histogram getHistogram(String name)

Get or construct a Histogram used to measure a distribution of values.

Parameters:

name - The name of the Histogram.

Returns:

An instance of Histogram.

getMeter

Meter getMeter(String name)

Get or construct a Meter used to measure durations and report distributions (a combination of a Timer and a Histogram.

Parameters:

name - The name of the Meter.

Returns:

An instance of Meter.

getCounter

Counter getCounter(String name)

Get or construct a Counter used to track a mutable number.

Parameters:

name - The name of the Counter

Returns:

An instance of Counter.

register

<T> void register(String name,
                  Gauge<T> gauge)

Register a Gauge. The Gauge will be invoked at a period defined by the implementation of MetricsSystem.

Type Parameters:

T - The type of the Gauge.

Parameters:

name - The name of the Gauge.

gauge - A callback to compute the current value.