org.apache.kafka.common.MetricName Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.kafka.common;
import java.util.Map;
import java.util.Objects;
/**
* 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:
*
{@code
* // set up metrics:
*
* Map metricTags = new LinkedHashMap();
* 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);
* }
*/
public final class MetricName {
private final String name;
private final String group;
private final String description;
private Map tags;
private int hash = 0;
/**
* Please create MetricName by method {@link org.apache.kafka.common.metrics.Metrics#metricName(String, String, String, Map)}
*
* @param name The name of the metric
* @param group logical group name of the metrics to which this metric belongs
* @param description A human-readable description to include in the metric
* @param tags additional key/value attributes of the metric
*/
public MetricName(String name, String group, String description, Map tags) {
this.name = Objects.requireNonNull(name);
this.group = Objects.requireNonNull(group);
this.description = Objects.requireNonNull(description);
this.tags = Objects.requireNonNull(tags);
}
public String name() {
return this.name;
}
public String group() {
return this.group;
}
public Map tags() {
return this.tags;
}
public String description() {
return this.description;
}
@Override
public int hashCode() {
if (hash != 0)
return hash;
final int prime = 31;
int result = 1;
result = prime * result + group.hashCode();
result = prime * result + name.hashCode();
result = prime * result + tags.hashCode();
this.hash = result;
return result;
}
@Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
MetricName other = (MetricName) obj;
return group.equals(other.group) && name.equals(other.name) && tags.equals(other.tags);
}
@Override
public String toString() {
return "MetricName [name=" + name + ", group=" + group + ", description="
+ description + ", tags=" + tags + "]";
}
}