/**
* 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.api;
import java.io.IOException;
import org.apache.hadoop.classification.InterfaceAudience.Public;
import org.apache.hadoop.classification.InterfaceStability.Stable;
import org.apache.hadoop.yarn.api.protocolrecords.GetContainerStatusesRequest;
import org.apache.hadoop.yarn.api.protocolrecords.GetContainerStatusesResponse;
import org.apache.hadoop.yarn.api.protocolrecords.StartContainerRequest;
import org.apache.hadoop.yarn.api.protocolrecords.StartContainersRequest;
import org.apache.hadoop.yarn.api.protocolrecords.StartContainersResponse;
import org.apache.hadoop.yarn.api.protocolrecords.StopContainersRequest;
import org.apache.hadoop.yarn.api.protocolrecords.StopContainersResponse;
import org.apache.hadoop.yarn.api.records.Container;
import org.apache.hadoop.yarn.api.records.ContainerId;
import org.apache.hadoop.yarn.api.records.ContainerLaunchContext;
import org.apache.hadoop.yarn.api.records.ContainerStatus;
import org.apache.hadoop.yarn.exceptions.NMNotYetReadyException;
import org.apache.hadoop.yarn.exceptions.YarnException;
/**
* <p>The protocol between an <code>ApplicationMaster</code> and a
* <code>NodeManager</code> to start/stop containers and to get status
* of running containers.</p>
*
* <p>If security is enabled the <code>NodeManager</code> verifies that the
* <code>ApplicationMaster</code> has truly been allocated the container
* by the <code>ResourceManager</code> and also verifies all interactions such
* as stopping the container or obtaining status information for the container.
* </p>
*/
@Public
@Stable
public interface ContainerManagementProtocol {
/**
* <p>
* The <code>ApplicationMaster</code> provides a list of
* {@link StartContainerRequest}s to a <code>NodeManager</code> to
* <em>start</em> {@link Container}s allocated to it using this interface.
* </p>
*
* <p>
* The <code>ApplicationMaster</code> has to provide details such as allocated
* resource capability, security tokens (if enabled), command to be executed
* to start the container, environment for the process, necessary
* binaries/jar/shared-objects etc. via the {@link ContainerLaunchContext} in
* the {@link StartContainerRequest}.
* </p>
*
* <p>
* The <code>NodeManager</code> sends a response via
* {@link StartContainersResponse} which includes a list of
* {@link Container}s of successfully launched {@link Container}s, a
* containerId-to-exception map for each failed {@link StartContainerRequest} in
* which the exception indicates errors from per container and a
* allServicesMetaData map between the names of auxiliary services and their
* corresponding meta-data. Note: None-container-specific exceptions will
* still be thrown by the API method itself.
* </p>
* <p>
* The <code>ApplicationMaster</code> can use
* {@link #getContainerStatuses(GetContainerStatusesRequest)} to get updated
* statuses of the to-be-launched or launched containers.
* </p>
*
* @param request
* request to start a list of containers
* @return response including conatinerIds of all successfully launched
* containers, a containerId-to-exception map for failed requests and
* a allServicesMetaData map.
* @throws YarnException
* @throws IOException
* @throws NMNotYetReadyException
* This exception is thrown when NM starts from scratch but has not
* yet connected with RM.
*/
@Public
@Stable
StartContainersResponse startContainers(StartContainersRequest request)
throws YarnException, IOException;
/**
* <p>
* The <code>ApplicationMaster</code> requests a <code>NodeManager</code> to
* <em>stop</em> a list of {@link Container}s allocated to it using this
* interface.
* </p>
*
* <p>
* The <code>ApplicationMaster</code> sends a {@link StopContainersRequest}
* which includes the {@link ContainerId}s of the containers to be stopped.
* </p>
*
* <p>
* The <code>NodeManager</code> sends a response via
* {@link StopContainersResponse} which includes a list of {@link ContainerId}
* s of successfully stopped containers, a containerId-to-exception map for
* each failed request in which the exception indicates errors from per
* container. Note: None-container-specific exceptions will still be thrown by
* the API method itself. <code>ApplicationMaster</code> can use
* {@link #getContainerStatuses(GetContainerStatusesRequest)} to get updated
* statuses of the containers.
* </p>
*
* @param request
* request to stop a list of containers
* @return response which includes a list of containerIds of successfully
* stopped containers, a containerId-to-exception map for failed
* requests.
* @throws YarnException
* @throws IOException
*/
@Public
@Stable
StopContainersResponse stopContainers(StopContainersRequest request)
throws YarnException, IOException;
/**
* <p>
* The API used by the <code>ApplicationMaster</code> to request for current
* statuses of <code>Container</code>s from the <code>NodeManager</code>.
* </p>
*
* <p>
* The <code>ApplicationMaster</code> sends a
* {@link GetContainerStatusesRequest} which includes the {@link ContainerId}s
* of all containers whose statuses are needed.
* </p>
*
* <p>
* The <code>NodeManager</code> responds with
* {@link GetContainerStatusesResponse} which includes a list of
* {@link ContainerStatus} of the successfully queried containers and a
* containerId-to-exception map for each failed request in which the exception
* indicates errors from per container. Note: None-container-specific
* exceptions will still be thrown by the API method itself.
* </p>
*
* @param request
* request to get <code>ContainerStatus</code>es of containers with
* the specified <code>ContainerId</code>s
* @return response containing the list of <code>ContainerStatus</code> of the
* successfully queried containers and a containerId-to-exception map
* for failed requests.
*
* @throws YarnException
* @throws IOException
*/
@Public
@Stable
GetContainerStatusesResponse getContainerStatuses(
GetContainerStatusesRequest request) throws YarnException,
IOException;
}