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.client.api.async.impl; import java.io.IOException; import java.nio.ByteBuffer; import java.util.EnumSet; import java.util.HashSet; import java.util.Map; import java.util.Set; import java.util.concurrent.BlockingQueue; import java.util.concurrent.ConcurrentHashMap; import java.util.concurrent.ConcurrentMap; import java.util.concurrent.LinkedBlockingQueue; import java.util.concurrent.ThreadFactory; import java.util.concurrent.ThreadPoolExecutor; import java.util.concurrent.TimeUnit; import java.util.concurrent.atomic.AtomicBoolean; import java.util.concurrent.locks.ReentrantReadWriteLock; import java.util.concurrent.locks.ReentrantReadWriteLock.ReadLock; import java.util.concurrent.locks.ReentrantReadWriteLock.WriteLock; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.hadoop.classification.InterfaceAudience.Private; import org.apache.hadoop.classification.InterfaceStability.Unstable; import org.apache.hadoop.conf.Configuration; 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.api.records.NodeId; import org.apache.hadoop.yarn.api.records.Token; import org.apache.hadoop.yarn.client.api.NMClient; import org.apache.hadoop.yarn.client.api.async.NMClientAsync; import org.apache.hadoop.yarn.client.api.impl.NMClientImpl; import org.apache.hadoop.yarn.conf.YarnConfiguration; import org.apache.hadoop.yarn.event.AbstractEvent; import org.apache.hadoop.yarn.event.EventHandler; import org.apache.hadoop.yarn.exceptions.YarnException; import org.apache.hadoop.yarn.ipc.RPCUtil; import org.apache.hadoop.yarn.state.InvalidStateTransitionException; import org.apache.hadoop.yarn.state.MultipleArcTransition; import org.apache.hadoop.yarn.state.SingleArcTransition; import org.apache.hadoop.yarn.state.StateMachine; import org.apache.hadoop.yarn.state.StateMachineFactory; import com.google.common.annotations.VisibleForTesting; import com.google.common.util.concurrent.ThreadFactoryBuilder; @Private @Unstable public class NMClientAsyncImpl extends NMClientAsync { private static final Log LOG = LogFactory.getLog(NMClientAsyncImpl.class); protected static final int INITIAL_THREAD_POOL_SIZE = 10; protected ThreadPoolExecutor threadPool; protected int maxThreadPoolSize; protected Thread eventDispatcherThread; protected AtomicBoolean stopped = new AtomicBoolean(false); protected BlockingQueue<ContainerEvent> events = new LinkedBlockingQueue<ContainerEvent>(); protected ConcurrentMap<ContainerId, StatefulContainer> containers = new ConcurrentHashMap<ContainerId, StatefulContainer>(); public NMClientAsyncImpl(AbstractCallbackHandler callbackHandler) { this(NMClientAsync.class.getName(), callbackHandler); } public NMClientAsyncImpl(String name, AbstractCallbackHandler callbackHandler) { this(name, new NMClientImpl(), callbackHandler); } @Private @VisibleForTesting protected NMClientAsyncImpl(String name, NMClient client, AbstractCallbackHandler callbackHandler) { super(name, client, callbackHandler); this.client = client; this.callbackHandler = callbackHandler; } /** * @deprecated Use {@link * #NMClientAsyncImpl(NMClientAsync.AbstractCallbackHandler)} * instead. */ @Deprecated public NMClientAsyncImpl(CallbackHandler callbackHandler) { this(NMClientAsync.class.getName(), callbackHandler); } /** * @deprecated Use {@link #NMClientAsyncImpl(String, * NMClientAsync.AbstractCallbackHandler)} instead. */ @Deprecated public NMClientAsyncImpl(String name, CallbackHandler callbackHandler) { this(name, new NMClientImpl(), callbackHandler); } @Private @VisibleForTesting @Deprecated protected NMClientAsyncImpl(String name, NMClient client, CallbackHandler callbackHandler) { super(name, client, callbackHandler); this.client = client; this.callbackHandler = callbackHandler; } @Override protected void serviceInit(Configuration conf) throws Exception { this.maxThreadPoolSize = conf.getInt(YarnConfiguration.NM_CLIENT_ASYNC_THREAD_POOL_MAX_SIZE, YarnConfiguration.DEFAULT_NM_CLIENT_ASYNC_THREAD_POOL_MAX_SIZE); LOG.info("Upper bound of the thread pool size is " + maxThreadPoolSize); client.init(conf); super.serviceInit(conf); } @Override protected void serviceStart() throws Exception { client.start(); ThreadFactory tf = new ThreadFactoryBuilder().setNameFormat(this.getClass().getName() + " #%d") .setDaemon(true).build(); // Start with a default core-pool size and change it dynamically. int initSize = Math.min(INITIAL_THREAD_POOL_SIZE, maxThreadPoolSize); threadPool = new ThreadPoolExecutor(initSize, Integer.MAX_VALUE, 1, TimeUnit.HOURS, new LinkedBlockingQueue<Runnable>(), tf); eventDispatcherThread = new Thread() { @Override public void run() { ContainerEvent event = null; Set<String> allNodes = new HashSet<String>(); while (!stopped.get() && !Thread.currentThread().isInterrupted()) { try { event = events.take(); } catch (InterruptedException e) { if (!stopped.get()) { LOG.error("Returning, thread interrupted", e); } return; } allNodes.add(event.getNodeId().toString()); int threadPoolSize = threadPool.getCorePoolSize(); // We can increase the pool size only if haven't reached the maximum // limit yet. if (threadPoolSize != maxThreadPoolSize) { // nodes where containers will run at *this* point of time. This is // *not* the cluster size and doesn't need to be. int nodeNum = allNodes.size(); int idealThreadPoolSize = Math.min(maxThreadPoolSize, nodeNum); if (threadPoolSize < idealThreadPoolSize) { // Bump up the pool size to idealThreadPoolSize + // INITIAL_POOL_SIZE, the later is just a buffer so we are not // always increasing the pool-size int newThreadPoolSize = Math.min(maxThreadPoolSize, idealThreadPoolSize + INITIAL_THREAD_POOL_SIZE); LOG.info("Set NMClientAsync thread pool size to " + newThreadPoolSize + " as the number of nodes to talk to is " + nodeNum); threadPool.setCorePoolSize(newThreadPoolSize); } } // the events from the queue are handled in parallel with a thread // pool threadPool.execute(getContainerEventProcessor(event)); // TODO: Group launching of multiple containers to a single // NodeManager into a single connection } } }; eventDispatcherThread.setName("Container Event Dispatcher"); eventDispatcherThread.setDaemon(false); eventDispatcherThread.start(); super.serviceStart(); } @Override protected void serviceStop() throws Exception { if (stopped.getAndSet(true)) { // return if already stopped return; } if (eventDispatcherThread != null) { eventDispatcherThread.interrupt(); try { eventDispatcherThread.join(); } catch (InterruptedException e) { LOG.error("The thread of " + eventDispatcherThread.getName() + " didn't finish normally.", e); } } if (threadPool != null) { threadPool.shutdownNow(); } if (client != null) { // If NMClientImpl doesn't stop running containers, the states doesn't // need to be cleared. if (!(client instanceof NMClientImpl) || ((NMClientImpl) client).getCleanupRunningContainers().get()) { if (containers != null) { containers.clear(); } } client.stop(); } super.serviceStop(); } public void startContainerAsync(Container container, ContainerLaunchContext containerLaunchContext) { if (containers.putIfAbsent(container.getId(), new StatefulContainer(this, container.getId())) != null) { callbackHandler.onStartContainerError(container.getId(), RPCUtil.getRemoteException( "Container " + container.getId() + " is already started or scheduled to start")); } try { events.put(new StartContainerEvent(container, containerLaunchContext)); } catch (InterruptedException e) { LOG.warn("Exception when scheduling the event of starting Container " + container.getId()); callbackHandler.onStartContainerError(container.getId(), e); } } public void increaseContainerResourceAsync(Container container) { if (!(callbackHandler instanceof AbstractCallbackHandler)) { LOG.error("Callback handler does not implement container resource " + "increase callback methods"); return; } AbstractCallbackHandler handler = (AbstractCallbackHandler) callbackHandler; if (containers.get(container.getId()) == null) { handler.onIncreaseContainerResourceError(container.getId(), RPCUtil.getRemoteException( "Container " + container.getId() + " is neither started nor scheduled to start")); } try { events.put(new IncreaseContainerResourceEvent(container)); } catch (InterruptedException e) { LOG.warn("Exception when scheduling the event of increasing resource of " + "Container " + container.getId()); handler.onIncreaseContainerResourceError(container.getId(), e); } } public void stopContainerAsync(ContainerId containerId, NodeId nodeId) { if (containers.get(containerId) == null) { callbackHandler.onStopContainerError(containerId, RPCUtil .getRemoteException("Container " + containerId + " is neither started nor scheduled to start")); } try { events.put(new ContainerEvent(containerId, nodeId, null, ContainerEventType.STOP_CONTAINER)); } catch (InterruptedException e) { LOG.warn("Exception when scheduling the event of stopping Container " + containerId); callbackHandler.onStopContainerError(containerId, e); } } public void getContainerStatusAsync(ContainerId containerId, NodeId nodeId) { try { events.put(new ContainerEvent(containerId, nodeId, null, ContainerEventType.QUERY_CONTAINER)); } catch (InterruptedException e) { LOG.warn("Exception when scheduling the event of querying the status" + " of Container " + containerId); callbackHandler.onGetContainerStatusError(containerId, e); } } protected static enum ContainerState { PREP, FAILED, RUNNING, DONE, } protected boolean isCompletelyDone(StatefulContainer container) { return container.getState() == ContainerState.DONE || container.getState() == ContainerState.FAILED; } protected ContainerEventProcessor getContainerEventProcessor(ContainerEvent event) { return new ContainerEventProcessor(event); } /** * The type of the event of interacting with a container */ protected static enum ContainerEventType { START_CONTAINER, STOP_CONTAINER, QUERY_CONTAINER, INCREASE_CONTAINER_RESOURCE } protected static class ContainerEvent extends AbstractEvent<ContainerEventType> { private ContainerId containerId; private NodeId nodeId; private Token containerToken; public ContainerEvent(ContainerId containerId, NodeId nodeId, Token containerToken, ContainerEventType type) { super(type); this.containerId = containerId; this.nodeId = nodeId; this.containerToken = containerToken; } public ContainerId getContainerId() { return containerId; } public NodeId getNodeId() { return nodeId; } public Token getContainerToken() { return containerToken; } } protected static class StartContainerEvent extends ContainerEvent { private Container container; private ContainerLaunchContext containerLaunchContext; public StartContainerEvent(Container container, ContainerLaunchContext containerLaunchContext) { super(container.getId(), container.getNodeId(), container.getContainerToken(), ContainerEventType.START_CONTAINER); this.container = container; this.containerLaunchContext = containerLaunchContext; } public Container getContainer() { return container; } public ContainerLaunchContext getContainerLaunchContext() { return containerLaunchContext; } } protected static class IncreaseContainerResourceEvent extends ContainerEvent { private Container container; public IncreaseContainerResourceEvent(Container container) { super(container.getId(), container.getNodeId(), container.getContainerToken(), ContainerEventType.INCREASE_CONTAINER_RESOURCE); this.container = container; } public Container getContainer() { return container; } } protected static class StatefulContainer implements EventHandler<ContainerEvent> { protected final static StateMachineFactory<StatefulContainer, ContainerState, ContainerEventType, ContainerEvent> stateMachineFactory = new StateMachineFactory<StatefulContainer, ContainerState, ContainerEventType, ContainerEvent>( ContainerState.PREP) // Transitions from PREP state .addTransition(ContainerState.PREP, EnumSet.of(ContainerState.RUNNING, ContainerState.FAILED), ContainerEventType.START_CONTAINER, new StartContainerTransition()) .addTransition(ContainerState.PREP, ContainerState.DONE, ContainerEventType.STOP_CONTAINER, new OutOfOrderTransition()) // Transitions from RUNNING state .addTransition(ContainerState.RUNNING, ContainerState.RUNNING, ContainerEventType.INCREASE_CONTAINER_RESOURCE, new IncreaseContainerResourceTransition()) .addTransition(ContainerState.RUNNING, EnumSet.of(ContainerState.DONE, ContainerState.FAILED), ContainerEventType.STOP_CONTAINER, new StopContainerTransition()) // Transition from DONE state .addTransition(ContainerState.DONE, ContainerState.DONE, EnumSet.of(ContainerEventType.START_CONTAINER, ContainerEventType.STOP_CONTAINER, ContainerEventType.INCREASE_CONTAINER_RESOURCE)) // Transition from FAILED state .addTransition(ContainerState.FAILED, ContainerState.FAILED, EnumSet.of(ContainerEventType.START_CONTAINER, ContainerEventType.STOP_CONTAINER, ContainerEventType.INCREASE_CONTAINER_RESOURCE)); protected static class StartContainerTransition implements MultipleArcTransition<StatefulContainer, ContainerEvent, ContainerState> { @Override public ContainerState transition(StatefulContainer container, ContainerEvent event) { ContainerId containerId = event.getContainerId(); try { StartContainerEvent scEvent = null; if (event instanceof StartContainerEvent) { scEvent = (StartContainerEvent) event; } assert scEvent != null; Map<String, ByteBuffer> allServiceResponse = container.nmClientAsync.getClient() .startContainer(scEvent.getContainer(), scEvent.getContainerLaunchContext()); try { container.nmClientAsync.getCallbackHandler().onContainerStarted(containerId, allServiceResponse); } catch (Throwable thr) { // Don't process user created unchecked exception LOG.info("Unchecked exception is thrown from onContainerStarted for " + "Container " + containerId, thr); } return ContainerState.RUNNING; } catch (YarnException e) { return onExceptionRaised(container, event, e); } catch (IOException e) { return onExceptionRaised(container, event, e); } catch (Throwable t) { return onExceptionRaised(container, event, t); } } private ContainerState onExceptionRaised(StatefulContainer container, ContainerEvent event, Throwable t) { try { container.nmClientAsync.getCallbackHandler().onStartContainerError(event.getContainerId(), t); } catch (Throwable thr) { // Don't process user created unchecked exception LOG.info("Unchecked exception is thrown from onStartContainerError for " + "Container " + event.getContainerId(), thr); } return ContainerState.FAILED; } } protected static class IncreaseContainerResourceTransition implements SingleArcTransition<StatefulContainer, ContainerEvent> { @Override public void transition(StatefulContainer container, ContainerEvent event) { if (!(container.nmClientAsync.getCallbackHandler() instanceof AbstractCallbackHandler)) { LOG.error("Callback handler does not implement container resource " + "increase callback methods"); return; } AbstractCallbackHandler handler = (AbstractCallbackHandler) container.nmClientAsync .getCallbackHandler(); try { if (!(event instanceof IncreaseContainerResourceEvent)) { throw new AssertionError("Unexpected event type. Expecting:" + "IncreaseContainerResourceEvent. Got:" + event); } IncreaseContainerResourceEvent increaseEvent = (IncreaseContainerResourceEvent) event; container.nmClientAsync.getClient().increaseContainerResource(increaseEvent.getContainer()); try { handler.onContainerResourceIncreased(increaseEvent.getContainerId(), increaseEvent.getContainer().getResource()); } catch (Throwable thr) { // Don't process user created unchecked exception LOG.info( "Unchecked exception is thrown from " + "onContainerResourceIncreased for Container " + event.getContainerId(), thr); } } catch (Exception e) { try { handler.onIncreaseContainerResourceError(event.getContainerId(), e); } catch (Throwable thr) { // Don't process user created unchecked exception LOG.info("Unchecked exception is thrown from " + "onIncreaseContainerResourceError for Container " + event.getContainerId(), thr); } } } } protected static class StopContainerTransition implements MultipleArcTransition<StatefulContainer, ContainerEvent, ContainerState> { @Override public ContainerState transition(StatefulContainer container, ContainerEvent event) { ContainerId containerId = event.getContainerId(); try { container.nmClientAsync.getClient().stopContainer(containerId, event.getNodeId()); try { container.nmClientAsync.getCallbackHandler().onContainerStopped(event.getContainerId()); } catch (Throwable thr) { // Don't process user created unchecked exception LOG.info("Unchecked exception is thrown from onContainerStopped for " + "Container " + event.getContainerId(), thr); } return ContainerState.DONE; } catch (YarnException e) { return onExceptionRaised(container, event, e); } catch (IOException e) { return onExceptionRaised(container, event, e); } catch (Throwable t) { return onExceptionRaised(container, event, t); } } private ContainerState onExceptionRaised(StatefulContainer container, ContainerEvent event, Throwable t) { try { container.nmClientAsync.getCallbackHandler().onStopContainerError(event.getContainerId(), t); } catch (Throwable thr) { // Don't process user created unchecked exception LOG.info("Unchecked exception is thrown from onStopContainerError for " + "Container " + event.getContainerId(), thr); } return ContainerState.FAILED; } } protected static class OutOfOrderTransition implements SingleArcTransition<StatefulContainer, ContainerEvent> { protected static final String STOP_BEFORE_START_ERROR_MSG = "Container was killed before it was launched"; @Override public void transition(StatefulContainer container, ContainerEvent event) { try { container.nmClientAsync.getCallbackHandler().onStartContainerError(event.getContainerId(), RPCUtil.getRemoteException(STOP_BEFORE_START_ERROR_MSG)); } catch (Throwable thr) { // Don't process user created unchecked exception LOG.info("Unchecked exception is thrown from onStartContainerError for " + "Container " + event.getContainerId(), thr); } } } private final NMClientAsync nmClientAsync; private final ContainerId containerId; private final StateMachine<ContainerState, ContainerEventType, ContainerEvent> stateMachine; private final ReadLock readLock; private final WriteLock writeLock; public StatefulContainer(NMClientAsync client, ContainerId containerId) { this.nmClientAsync = client; this.containerId = containerId; stateMachine = stateMachineFactory.make(this); ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); readLock = lock.readLock(); writeLock = lock.writeLock(); } @Override public void handle(ContainerEvent event) { writeLock.lock(); try { try { this.stateMachine.doTransition(event.getType(), event); } catch (InvalidStateTransitionException e) { LOG.error("Can't handle this event at current state", e); } } finally { writeLock.unlock(); } } public ContainerId getContainerId() { return containerId; } public ContainerState getState() { readLock.lock(); try { return stateMachine.getCurrentState(); } finally { readLock.unlock(); } } } protected class ContainerEventProcessor implements Runnable { protected ContainerEvent event; public ContainerEventProcessor(ContainerEvent event) { this.event = event; } @Override public void run() { ContainerId containerId = event.getContainerId(); LOG.info("Processing Event " + event + " for Container " + containerId); if (event.getType() == ContainerEventType.QUERY_CONTAINER) { try { ContainerStatus containerStatus = client.getContainerStatus(containerId, event.getNodeId()); try { callbackHandler.onContainerStatusReceived(containerId, containerStatus); } catch (Throwable thr) { // Don't process user created unchecked exception LOG.info("Unchecked exception is thrown from onContainerStatusReceived" + " for Container " + event.getContainerId(), thr); } } catch (YarnException e) { onExceptionRaised(containerId, e); } catch (IOException e) { onExceptionRaised(containerId, e); } catch (Throwable t) { onExceptionRaised(containerId, t); } } else { StatefulContainer container = containers.get(containerId); if (container == null) { LOG.info("Container " + containerId + " is already stopped or failed"); } else { container.handle(event); if (isCompletelyDone(container)) { containers.remove(containerId); } } } } private void onExceptionRaised(ContainerId containerId, Throwable t) { try { callbackHandler.onGetContainerStatusError(containerId, t); } catch (Throwable thr) { // Don't process user created unchecked exception LOG.info("Unchecked exception is thrown from onGetContainerStatusError" + " for Container " + containerId, thr); } } } }