rnpridgeon commented on a change in pull request #8691: URL: https://github.com/apache/kafka/pull/8691#discussion_r429370889
########## File path: clients/src/main/java/org/apache/kafka/common/metrics/KafkaMetricsContext.java ########## @@ -0,0 +1,56 @@ +/* + * 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 java.util.Collections; +import java.util.HashMap; +import java.util.Map; + +/** + * A implementation of MetricsContext, it encapsulates required metrics context properties for Kafka services and clients + */ +public class KafkaMetricsContext implements MetricsContext { + /** + * Client or Service's metadata map. + */ + private Map<String, String> metadata = new HashMap<>(); + + /** + * Create a MetricsContext with namespace, no service or client properties + * @param namespace value for _namespace key + */ + public KafkaMetricsContext(String namespace) { + this(namespace, new HashMap<>()); + } + + /** + * Create a MetricsContext with namespace, service or client properties + * @param namespace value for _namespace key + * @param metadata metadata additional entries to add to the context. + * values will be converted to string using Object.toString() + */ + public KafkaMetricsContext(String namespace, Map<String, ?> metadata) { + this.metadata.put(MetricsContext.NAMESPACE, namespace); + metadata.forEach((key, value) -> this.metadata.put(key, value.toString())); Review comment: Mostly I'm concerned about the case where some composite may share similar labels to the underlying client it manages. If we allow the downstream client to overwrite such a label we will lose a portion of the upstream components context. ---------------------------------------------------------------- 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
