Package org.apache.kafka.common

Class MetricName

java.lang.Object

org.apache.kafka.common.MetricName

public final class MetricName
extends java.lang.Object

The MetricName class encapsulates a metric's name, logical group and its related attributes. It should be constructed using metrics.MetricName(...).

This class captures the following parameters

  name The name of the metric
  group logical group name of the metrics to which this metric belongs.
  description A human-readable description to include in the metric. This is optional.
  tags additional key/value attributes of the metric. This is optional.
 

group, tags parameters can be used to create unique metric names while reporting in JMX or any custom reporting.

Ex: standard JMX MBean can be constructed like domainName:type=group,key1=val1,key2=val2

Usage looks something like this:

 // set up metrics:

 Map<String, String> metricTags = new LinkedHashMap<String, String>();
 metricTags.put("client-id", "producer-1");
 metricTags.put("topic", "topic");

 MetricConfig metricConfig = new MetricConfig().tags(metricTags);
 Metrics metrics = new Metrics(metricConfig); // this is the global repository of metrics and sensors

 Sensor sensor = metrics.sensor("message-sizes");

 MetricName metricName = metrics.metricName("message-size-avg", "producer-metrics", "average message size");
 sensor.add(metricName, new Avg());

 metricName = metrics.metricName("message-size-max", "producer-metrics");
 sensor.add(metricName, new Max());

 metricName = metrics.metricName("message-size-min", "producer-metrics", "message minimum size", "client-id", "my-client", "topic", "my-topic");
 sensor.add(metricName, new Min());

 // as messages are sent we record the sizes
 sensor.record(messageSize);
 

Constructor Summary

Constructors

Constructor	Description
MetricName(java.lang.String name, java.lang.String group, java.lang.String description, java.util.Map<java.lang.String,java.lang.String> tags)	Please create MetricName by method Metrics.metricName(String, String, String, Map)

Method Summary

Modifier and Type	Method	Description
java.lang.String	description()
boolean	equals(java.lang.Object obj)
java.lang.String	group()
int	hashCode()
java.lang.String	name()
java.util.Map<java.lang.String,java.lang.String>	tags()
java.lang.String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

MetricName

public MetricName(java.lang.String name,
                  java.lang.String group,
                  java.lang.String description,
                  java.util.Map<java.lang.String,java.lang.String> tags)

Please create MetricName by method Metrics.metricName(String, String, String, Map)

Parameters:

name - The name of the metric

group - logical group name of the metrics to which this metric belongs

description - A human-readable description to include in the metric

tags - additional key/value attributes of the metric

Method Detail

name

public java.lang.String name()

group

public java.lang.String group()

tags

public java.util.Map<java.lang.String,java.lang.String> tags()

description

public java.lang.String description()

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

equals

public boolean equals(java.lang.Object obj)

Overrides:

equals in class java.lang.Object

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object