org.apache.hadoop.yarn.server.api.AuxiliaryService 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.hadoop.yarn.server.api;
import java.nio.ByteBuffer;
import org.apache.hadoop.classification.InterfaceAudience.Public;
import org.apache.hadoop.classification.InterfaceStability.Evolving;
import org.apache.hadoop.service.AbstractService;
import org.apache.hadoop.yarn.api.ContainerManagementProtocol;
import org.apache.hadoop.yarn.api.protocolrecords.StartContainersRequest;
import org.apache.hadoop.yarn.api.protocolrecords.StartContainersResponse;
import org.apache.hadoop.yarn.conf.YarnConfiguration;
/**
* A generic service that will be started by the NodeManager. This is a service
* that administrators have to configure on each node by setting
* {@link YarnConfiguration#NM_AUX_SERVICES}.
*
*/
@Public
@Evolving
public abstract class AuxiliaryService extends AbstractService {
protected AuxiliaryService(String name) {
super(name);
}
/**
* A new application is started on this NodeManager. This is a signal to
* this {@link AuxiliaryService} about the application initialization.
*
* @param initAppContext context for the application's initialization
*/
public abstract void initializeApplication(
ApplicationInitializationContext initAppContext);
/**
* An application is finishing on this NodeManager. This is a signal to this
* {@link AuxiliaryService} about the same.
*
* @param stopAppContext context for the application termination
*/
public abstract void stopApplication(
ApplicationTerminationContext stopAppContext);
/**
* Retrieve meta-data for this {@link AuxiliaryService}. Applications using
* this {@link AuxiliaryService} SHOULD know the format of the meta-data -
* ideally each service should provide a method to parse out the information
* to the applications. One example of meta-data is contact information so
* that applications can access the service remotely. This will only be called
* after the service's {@link #start()} method has finished. the result may be
* cached.
*
*
* The information is passed along to applications via
* {@link StartContainersResponse#getAllServicesMetaData()} that is returned by
* {@link ContainerManagementProtocol#startContainers(StartContainersRequest)}
*
*
* @return meta-data for this service that should be made available to
* applications.
*/
public abstract ByteBuffer getMetaData();
/**
* A new container is started on this NodeManager. This is a signal to
* this {@link AuxiliaryService} about the container initialization.
* This method is called when the NodeManager receives the container launch
* command from the ApplicationMaster and before the container process is
* launched.
*
* @param initContainerContext context for the container's initialization
*/
public void initializeContainer(ContainerInitializationContext
initContainerContext) {
}
/**
* A container is finishing on this NodeManager. This is a signal to this
* {@link AuxiliaryService} about the same.
*
* @param stopContainerContext context for the container termination
*/
public void stopContainer(ContainerTerminationContext stopContainerContext) {
}
}