org.apache.flink.runtime.leaderretrieval.LeaderRetrievalService 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.flink.runtime.leaderretrieval;
/**
* This interface has to be implemented by a service which retrieves the current leader and notifies
* a listener about it.
*
* Prior to using this service it has to be started by calling the start method. The start method
* also takes the {@link LeaderRetrievalListener} as an argument. The service can only be started
* once.
*
*
The service should be stopped by calling the stop method.
*/
public interface LeaderRetrievalService {
/**
* Starts the leader retrieval service with the given listener to listen for new leaders. This
* method can only be called once.
*
* @param listener The leader retrieval listener which will be notified about new leaders.
* @throws Exception
*/
void start(LeaderRetrievalListener listener) throws Exception;
/**
* Stops the leader retrieval service.
*
* @throws Exception
*/
void stop() throws Exception;
}