xvrl commented on a change in pull request #8691: URL: https://github.com/apache/kafka/pull/8691#discussion_r429442671
########## File path: clients/src/main/java/org/apache/kafka/common/metrics/MetricsContext.java ########## @@ -0,0 +1,47 @@ +/* + * 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 metadata about metrics exposed via a + * {@link org.apache.kafka.common.metrics.MetricsReporter} + * + * The metadata map provides following information: + * - a <code>_namespace</node> field indicating the component exposing metrics + * e.g. kafka.server, kafka.consumer + * {@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 `metrics.context.<key>=<value> + * + * - 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 Review comment: I think the interface is a natural way to expose predefined constants an API might need. I don't see a need to have a separate class for this yet. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org
