org.apache.kafka.common.ClusterResourceListener Maven / Gradle / Ivy
/*
* 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;
/**
* A callback interface that users can implement when they wish to get notified about changes in the Cluster metadata.
*
* Users who need access to cluster metadata in interceptors, metric reporters, serializers and deserializers
* can implement this interface. The order of method calls for each of these types is described below.
*
*
Clients
* There will be one invocation of {@link ClusterResourceListener#onUpdate(ClusterResource)} after each metadata response.
* Note that the cluster id may be null when the Kafka broker version is below 0.10.1.0. If you receive a null cluster id, you can expect it to always be null unless you have a cluster with multiple broker versions which can happen if the cluster is being upgraded while the client is running.
*
* {@link org.apache.kafka.clients.producer.ProducerInterceptor} : The {@link ClusterResourceListener#onUpdate(ClusterResource)} method will be invoked after {@link org.apache.kafka.clients.producer.ProducerInterceptor#onSend(org.apache.kafka.clients.producer.ProducerRecord)}
* but before {@link org.apache.kafka.clients.producer.ProducerInterceptor#onAcknowledgement(org.apache.kafka.clients.producer.RecordMetadata, Exception)} .
*
* {@link org.apache.kafka.clients.consumer.ConsumerInterceptor} : The {@link ClusterResourceListener#onUpdate(ClusterResource)} method will be invoked before {@link org.apache.kafka.clients.consumer.ConsumerInterceptor#onConsume(org.apache.kafka.clients.consumer.ConsumerRecords)}
*
* {@link org.apache.kafka.common.serialization.Serializer} : The {@link ClusterResourceListener#onUpdate(ClusterResource)} method will be invoked before {@link org.apache.kafka.common.serialization.Serializer#serialize(String, Object)}
*
* {@link org.apache.kafka.common.serialization.Deserializer} : The {@link ClusterResourceListener#onUpdate(ClusterResource)} method will be invoked before {@link org.apache.kafka.common.serialization.Deserializer#deserialize(String, byte[])}
*
* {@link org.apache.kafka.common.metrics.MetricsReporter} : The {@link ClusterResourceListener#onUpdate(ClusterResource)} method will be invoked after first {@link org.apache.kafka.clients.producer.KafkaProducer#send(org.apache.kafka.clients.producer.ProducerRecord)} invocation for Producer metrics reporter
* and after first {@link org.apache.kafka.clients.consumer.KafkaConsumer#poll(java.time.Duration)} invocation for Consumer metrics
* reporters. The reporter may receive metric events from the network layer before this method is invoked.
*
Broker
* There is a single invocation {@link ClusterResourceListener#onUpdate(ClusterResource)} on broker start-up and the cluster metadata will never change.
*
* KafkaMetricsReporter : The {@link ClusterResourceListener#onUpdate(ClusterResource)} method will be invoked during the bootup of the Kafka broker. The reporter may receive metric events from the network layer before this method is invoked.
*
* {@link org.apache.kafka.common.metrics.MetricsReporter} : The {@link ClusterResourceListener#onUpdate(ClusterResource)} method will be invoked during the bootup of the Kafka broker. The reporter may receive metric events from the network layer before this method is invoked.
*/
public interface ClusterResourceListener {
/**
* A callback method that a user can implement to get updates for {@link ClusterResource}.
* @param clusterResource cluster metadata
*/
void onUpdate(ClusterResource clusterResource);
}