org.apache.flink.runtime.jobmanager.JobGraphStoreWatcher Maven / Gradle / Ivy
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* 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
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* 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
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*/
package org.apache.flink.runtime.jobmanager;
/**
* A watcher on {@link JobGraphStore}. It could monitor all the changes on the job graph store and
* notify the {@link JobGraphStore} via {@link JobGraphStore.JobGraphListener}.
*
* Important: The {@link JobGraphStoreWatcher} could not guarantee that there is
* no {@link JobGraphStore.JobGraphListener} callbacks happen after {@link #stop()}. So the
* implementor is responsible for filtering out these spurious callbacks.
*/
public interface JobGraphStoreWatcher {
/**
* Start the watcher on {@link JobGraphStore}.
*
* @param jobGraphListener use jobGraphListener to notify the {@link DefaultJobGraphStore}
* @throws Exception when start internal services
*/
void start(JobGraphStore.JobGraphListener jobGraphListener) throws Exception;
/**
* Stop the watcher on {@link JobGraphStore}.
*
* @throws Exception when stop internal services
*/
void stop() throws Exception;
}