org.apache.kafka.common.metrics.MetricsContext Maven / Gradle / Ivy
The newest version!
/*
* 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.metrics;
import org.apache.kafka.common.annotation.InterfaceStability;
import java.util.Map;
/**
* MetricsContext encapsulates additional contextLabels about metrics exposed via a
* {@link org.apache.kafka.common.metrics.MetricsReporter}
*
* The {@link #contextLabels()} map provides following information:
*
* - in all components
* - a {@code _namespace} field indicating the component exposing metrics
* e.g. kafka.server, kafka.consumer.
* The {@link JmxReporter} uses this as prefix for MBean names
*
* - for clients and streams libraries
* - any freeform fields passed in via
* client properties in the form of {@code metrics.context.
=}
*
* - for kafka brokers
* - kafka.broker.id, kafka.cluster.id
*
* - for connect workers
* - connect.kafka.cluster.id, connect.group.id
*
*/
@InterfaceStability.Evolving
public interface MetricsContext {
/* predefined fields */
String NAMESPACE = "_namespace"; // metrics namespace, formerly jmx prefix
/**
* Returns the labels for this metrics context.
*
* @return the map of label keys and values; never null but possibly empty
*/
Map contextLabels();
}