Java tutorial
/** * 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.records; import org.apache.hadoop.classification.InterfaceAudience.Private; import org.apache.hadoop.classification.InterfaceAudience.Public; import org.apache.hadoop.classification.InterfaceStability.Evolving; import org.apache.hadoop.classification.InterfaceStability.Stable; import org.apache.hadoop.classification.InterfaceStability.Unstable; import org.apache.hadoop.yarn.api.ApplicationMasterProtocol; import org.apache.hadoop.yarn.api.ContainerManagementProtocol; import org.apache.hadoop.yarn.util.Records; import java.util.Collections; import java.util.Set; /** * {@code Container} represents an allocated resource in the cluster. * <p> * The {@code ResourceManager} is the sole authority to allocate any * {@code Container} to applications. The allocated {@code Container} * is always on a single node and has a unique {@link ContainerId}. It has * a specific amount of {@link Resource} allocated. * <p> * It includes details such as: * <ul> * <li>{@link ContainerId} for the container, which is globally unique.</li> * <li> * {@link NodeId} of the node on which it is allocated. * </li> * <li>HTTP uri of the node.</li> * <li>{@link Resource} allocated to the container.</li> * <li>{@link Priority} at which the container was allocated.</li> * <li> * Container {@link Token} of the container, used to securely verify * authenticity of the allocation. * </li> * </ul> * * Typically, an {@code ApplicationMaster} receives the {@code Container} * from the {@code ResourceManager} during resource-negotiation and then * talks to the {@code NodeManager} to start/stop containers. * * @see ApplicationMasterProtocol#allocate(org.apache.hadoop.yarn.api.protocolrecords.AllocateRequest) * @see ContainerManagementProtocol#startContainers(org.apache.hadoop.yarn.api.protocolrecords.StartContainersRequest) * @see ContainerManagementProtocol#stopContainers(org.apache.hadoop.yarn.api.protocolrecords.StopContainersRequest) */ @Public @Stable public abstract class Container implements Comparable<Container> { @Private @Unstable public static Container newInstance(ContainerId containerId, NodeId nodeId, String nodeHttpAddress, Resource resource, Priority priority, Token containerToken) { return newInstance(containerId, nodeId, nodeHttpAddress, resource, priority, containerToken, ExecutionType.GUARANTEED); } @Private @Unstable public static Container newInstance(ContainerId containerId, NodeId nodeId, String nodeHttpAddress, Resource resource, Priority priority, Token containerToken, ExecutionType executionType) { Container container = Records.newRecord(Container.class); container.setId(containerId); container.setNodeId(nodeId); container.setNodeHttpAddress(nodeHttpAddress); container.setResource(resource); container.setPriority(priority); container.setContainerToken(containerToken); container.setExecutionType(executionType); return container; } /** * Get the globally unique identifier for the container. * @return globally unique identifier for the container */ @Public @Stable public abstract ContainerId getId(); @Private @Unstable public abstract void setId(ContainerId id); /** * Get the identifier of the node on which the container is allocated. * @return identifier of the node on which the container is allocated */ @Public @Stable public abstract NodeId getNodeId(); @Private @Unstable public abstract void setNodeId(NodeId nodeId); /** * Get the http uri of the node on which the container is allocated. * @return http uri of the node on which the container is allocated */ @Public @Stable public abstract String getNodeHttpAddress(); @Private @Unstable public abstract void setNodeHttpAddress(String nodeHttpAddress); /** * Get the <code>Resource</code> allocated to the container. * @return <code>Resource</code> allocated to the container */ @Public @Stable public abstract Resource getResource(); @Private @Unstable public abstract void setResource(Resource resource); /** * Get the <code>Priority</code> at which the <code>Container</code> was * allocated. * @return <code>Priority</code> at which the <code>Container</code> was * allocated */ @Public @Stable public abstract Priority getPriority(); @Private @Unstable public abstract void setPriority(Priority priority); /** * Get the <code>ContainerToken</code> for the container. * <p><code>ContainerToken</code> is the security token used by the framework * to verify authenticity of any <code>Container</code>.</p> * * <p>The <code>ResourceManager</code>, on container allocation provides a * secure token which is verified by the <code>NodeManager</code> on * container launch.</p> * * <p>Applications do not need to care about <code>ContainerToken</code>, they * are transparently handled by the framework - the allocated * <code>Container</code> includes the <code>ContainerToken</code>.</p> * * @see ApplicationMasterProtocol#allocate(org.apache.hadoop.yarn.api.protocolrecords.AllocateRequest) * @see ContainerManagementProtocol#startContainers(org.apache.hadoop.yarn.api.protocolrecords.StartContainersRequest) * * @return <code>ContainerToken</code> for the container */ @Public @Stable public abstract Token getContainerToken(); @Private @Unstable public abstract void setContainerToken(Token containerToken); /** * Get the <code>ExecutionType</code> for the container. * @return <code>ExecutionType</code> for the container. */ @Private @Unstable public abstract ExecutionType getExecutionType(); /** * Set the <code>ExecutionType</code> for the container. * @param executionType ExecutionType */ @Private @Unstable public abstract void setExecutionType(ExecutionType executionType); /** * Get the optional <em>ID</em> corresponding to the original {@code * ResourceRequest{@link #getAllocationRequestId()}}s which is satisfied by * this allocated {@code Container}. * <p> * The scheduler may return multiple {@code AllocateResponse}s corresponding * to the same ID as and when scheduler allocates {@code Container}s. * <b>Applications</b> can continue to completely ignore the returned ID in * the response and use the allocation for any of their outstanding requests. * <p> * * @return the <em>ID</em> corresponding to the original allocation request * which is satisfied by this allocation. */ @Public @Evolving public long getAllocationRequestId() { throw new UnsupportedOperationException(); } /** * Set the optional <em>ID</em> corresponding to the original {@code * ResourceRequest{@link #setAllocationRequestId(long)} * etAllocationRequestId()}}s which is satisfied by this allocated {@code * Container}. * <p> * The scheduler may return multiple {@code AllocateResponse}s corresponding * to the same ID as and when scheduler allocates {@code Container}s. * <b>Applications</b> can continue to completely ignore the returned ID in * the response and use the allocation for any of their outstanding requests. * If the ID is not set, scheduler will continue to work as previously and all * allocated {@code Container}(s) will have the default ID, -1. * <p> * * @param allocationRequestID the <em>ID</em> corresponding to the original * allocation request which is satisfied by this * allocation. */ @Private @Unstable public void setAllocationRequestId(long allocationRequestID) { throw new UnsupportedOperationException(); } /** * Get the version of this container. The version will be incremented when * a container is updated. * * @return version of this container. */ @Private @Unstable public int getVersion() { return 0; } /** * Set the version of this container. * @param version of this container. */ @Private @Unstable public void setVersion(int version) { throw new UnsupportedOperationException(); } @Private @Unstable public Set<String> getAllocationTags() { return Collections.emptySet(); } @Private @Unstable public void setAllocationTags(Set<String> allocationTags) { } }