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.impl; import java.net.InetSocketAddress; import java.util.ArrayList; import java.util.Collections; import java.util.LinkedHashMap; import java.util.List; import java.util.Map; import org.apache.hadoop.classification.InterfaceAudience.LimitedPrivate; import org.apache.hadoop.classification.InterfaceAudience.Private; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.fs.CommonConfigurationKeysPublic; import org.apache.hadoop.net.NetUtils; import org.apache.hadoop.security.UserGroupInformation; import org.apache.hadoop.security.token.SecretManager.InvalidToken; import org.apache.hadoop.yarn.api.ContainerManagementProtocol; import org.apache.hadoop.yarn.api.records.ContainerId; import org.apache.hadoop.yarn.api.records.Token; import org.apache.hadoop.yarn.client.NMProxy; import org.apache.hadoop.yarn.client.api.NMTokenCache; import org.apache.hadoop.yarn.conf.YarnConfiguration; import org.apache.hadoop.yarn.exceptions.YarnRuntimeException; import org.apache.hadoop.yarn.ipc.YarnRPC; import org.apache.hadoop.yarn.security.NMTokenIdentifier; import org.apache.hadoop.yarn.util.ConverterUtils; import com.google.common.annotations.VisibleForTesting; import org.slf4j.Logger; import org.slf4j.LoggerFactory; /** * Helper class to manage container manager proxies */ @LimitedPrivate({ "MapReduce", "YARN" }) public class ContainerManagementProtocolProxy { static final Logger LOG = LoggerFactory.getLogger(ContainerManagementProtocolProxy.class); private final int maxConnectedNMs; private final Map<String, ContainerManagementProtocolProxyData> cmProxy; private final Configuration conf; private final YarnRPC rpc; private NMTokenCache nmTokenCache; public ContainerManagementProtocolProxy(Configuration conf) { this(conf, NMTokenCache.getSingleton()); } public ContainerManagementProtocolProxy(Configuration conf, NMTokenCache nmTokenCache) { this.conf = new Configuration(conf); this.nmTokenCache = nmTokenCache; maxConnectedNMs = conf.getInt(YarnConfiguration.NM_CLIENT_MAX_NM_PROXIES, YarnConfiguration.DEFAULT_NM_CLIENT_MAX_NM_PROXIES); if (maxConnectedNMs < 0) { throw new YarnRuntimeException(YarnConfiguration.NM_CLIENT_MAX_NM_PROXIES + " (" + maxConnectedNMs + ") can not be less than 0."); } if (LOG.isDebugEnabled()) { LOG.debug(YarnConfiguration.NM_CLIENT_MAX_NM_PROXIES + " : " + maxConnectedNMs); } if (maxConnectedNMs > 0) { cmProxy = new LinkedHashMap<String, ContainerManagementProtocolProxyData>(); } else { cmProxy = Collections.emptyMap(); // Connections are not being cached so ensure connections close quickly // to avoid creating thousands of RPC client threads on large clusters. this.conf.setInt(CommonConfigurationKeysPublic.IPC_CLIENT_CONNECTION_MAXIDLETIME_KEY, 0); } rpc = YarnRPC.create(conf); } public synchronized ContainerManagementProtocolProxyData getProxy(String containerManagerBindAddr, ContainerId containerId) throws InvalidToken { // This get call will update the map which is working as LRU cache. ContainerManagementProtocolProxyData proxy = cmProxy.get(containerManagerBindAddr); while (proxy != null && !proxy.token.getIdentifier() .equals(nmTokenCache.getToken(containerManagerBindAddr).getIdentifier())) { if (LOG.isDebugEnabled()) { LOG.debug("Refreshing proxy as NMToken got updated for node : " + containerManagerBindAddr); } // Token is updated. check if anyone has already tried closing it. if (!proxy.scheduledForClose) { // try closing the proxy. Here if someone is already using it // then we might not close it. In which case we will wait. removeProxy(proxy); } else { try { this.wait(); } catch (InterruptedException e) { e.printStackTrace(); } } if (proxy.activeCallers < 0) { proxy = cmProxy.get(containerManagerBindAddr); } } if (proxy == null) { proxy = new ContainerManagementProtocolProxyData(rpc, containerManagerBindAddr, containerId, nmTokenCache.getToken(containerManagerBindAddr)); if (maxConnectedNMs > 0) { addProxyToCache(containerManagerBindAddr, proxy); } } // This is to track active users of this proxy. proxy.activeCallers++; updateLRUCache(containerManagerBindAddr); return proxy; } private void addProxyToCache(String containerManagerBindAddr, ContainerManagementProtocolProxyData proxy) { while (cmProxy.size() >= maxConnectedNMs) { if (LOG.isDebugEnabled()) { LOG.debug("Cleaning up the proxy cache, size=" + cmProxy.size() + " max=" + maxConnectedNMs); } boolean removedProxy = false; for (ContainerManagementProtocolProxyData otherProxy : cmProxy.values()) { removedProxy = removeProxy(otherProxy); if (removedProxy) { break; } } if (!removedProxy) { // all of the proxies are currently in use and already scheduled // for removal, so we need to wait until at least one of them closes try { this.wait(); } catch (InterruptedException e) { e.printStackTrace(); } } } if (maxConnectedNMs > 0) { cmProxy.put(containerManagerBindAddr, proxy); } } private void updateLRUCache(String containerManagerBindAddr) { if (maxConnectedNMs > 0) { ContainerManagementProtocolProxyData proxy = cmProxy.remove(containerManagerBindAddr); cmProxy.put(containerManagerBindAddr, proxy); } } public synchronized void mayBeCloseProxy(ContainerManagementProtocolProxyData proxy) { tryCloseProxy(proxy); } private boolean tryCloseProxy(ContainerManagementProtocolProxyData proxy) { proxy.activeCallers--; if (proxy.scheduledForClose && proxy.activeCallers < 0) { if (LOG.isDebugEnabled()) { LOG.debug("Closing proxy : " + proxy.containerManagerBindAddr); } cmProxy.remove(proxy.containerManagerBindAddr); try { rpc.stopProxy(proxy.getContainerManagementProtocol(), conf); } finally { this.notifyAll(); } return true; } return false; } private synchronized boolean removeProxy(ContainerManagementProtocolProxyData proxy) { if (!proxy.scheduledForClose) { proxy.scheduledForClose = true; return tryCloseProxy(proxy); } return false; } public synchronized void stopAllProxies() { List<String> nodeIds = new ArrayList<String>(); nodeIds.addAll(this.cmProxy.keySet()); for (String nodeId : nodeIds) { ContainerManagementProtocolProxyData proxy = cmProxy.get(nodeId); // Explicitly reducing the proxy count to allow stopping proxy. proxy.activeCallers = 0; try { removeProxy(proxy); } catch (Throwable t) { LOG.error("Error closing connection", t); } } cmProxy.clear(); } public class ContainerManagementProtocolProxyData { private final String containerManagerBindAddr; private final ContainerManagementProtocol proxy; private int activeCallers; private boolean scheduledForClose; private final Token token; @Private @VisibleForTesting public ContainerManagementProtocolProxyData(YarnRPC rpc, String containerManagerBindAddr, ContainerId containerId, Token token) throws InvalidToken { this.containerManagerBindAddr = containerManagerBindAddr; ; this.activeCallers = 0; this.scheduledForClose = false; this.token = token; this.proxy = newProxy(rpc, containerManagerBindAddr, containerId, token); } @Private @VisibleForTesting protected ContainerManagementProtocol newProxy(final YarnRPC rpc, String containerManagerBindAddr, ContainerId containerId, Token token) throws InvalidToken { if (token == null) { throw new InvalidToken("No NMToken sent for " + containerManagerBindAddr); } final InetSocketAddress cmAddr = NetUtils.createSocketAddr(containerManagerBindAddr); if (LOG.isDebugEnabled()) { LOG.debug("Opening proxy : " + containerManagerBindAddr); } // the user in createRemoteUser in this context has to be ContainerID UserGroupInformation user = UserGroupInformation .createRemoteUser(containerId.getApplicationAttemptId().toString()); org.apache.hadoop.security.token.Token<NMTokenIdentifier> nmToken = ConverterUtils .convertFromYarn(token, cmAddr); user.addToken(nmToken); return NMProxy.createNMProxy(conf, ContainerManagementProtocol.class, user, rpc, cmAddr); } public ContainerManagementProtocol getContainerManagementProtocol() { return proxy; } } }