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 com.cloud.agent; import java.io.File; import java.io.IOException; import java.io.PrintWriter; import java.io.StringWriter; import java.net.InetAddress; import java.net.UnknownHostException; import java.nio.channels.ClosedChannelException; import java.nio.charset.Charset; import java.util.ArrayList; import java.util.List; import java.util.Map; import java.util.Timer; import java.util.concurrent.ExecutorService; import java.util.concurrent.LinkedBlockingQueue; import java.util.concurrent.SynchronousQueue; import java.util.concurrent.ThreadPoolExecutor; import java.util.concurrent.TimeUnit; import java.util.concurrent.atomic.AtomicInteger; import javax.naming.ConfigurationException; import org.apache.cloudstack.ca.SetupCertificateAnswer; import org.apache.cloudstack.ca.SetupCertificateCommand; import org.apache.cloudstack.ca.SetupKeyStoreCommand; import org.apache.cloudstack.ca.SetupKeystoreAnswer; import org.apache.cloudstack.managed.context.ManagedContextTimerTask; import org.apache.cloudstack.utils.security.KeyStoreUtils; import org.apache.commons.io.FileUtils; import org.apache.log4j.Logger; import org.slf4j.MDC; import com.cloud.agent.api.AgentControlAnswer; import com.cloud.agent.api.AgentControlCommand; import com.cloud.agent.api.Answer; import com.cloud.agent.api.Command; import com.cloud.agent.api.CronCommand; import com.cloud.agent.api.MaintainAnswer; import com.cloud.agent.api.MaintainCommand; import com.cloud.agent.api.PingCommand; import com.cloud.agent.api.ReadyCommand; import com.cloud.agent.api.ShutdownCommand; import com.cloud.agent.api.StartupAnswer; import com.cloud.agent.api.StartupCommand; import com.cloud.agent.transport.Request; import com.cloud.agent.transport.Response; import com.cloud.exception.AgentControlChannelException; import com.cloud.resource.ServerResource; import com.cloud.utils.PropertiesUtil; import com.cloud.utils.backoff.BackoffAlgorithm; import com.cloud.utils.concurrency.NamedThreadFactory; import com.cloud.utils.exception.CloudRuntimeException; import com.cloud.utils.exception.NioConnectionException; import com.cloud.utils.exception.TaskExecutionException; import com.cloud.utils.nio.HandlerFactory; import com.cloud.utils.nio.Link; import com.cloud.utils.nio.NioClient; import com.cloud.utils.nio.NioConnection; import com.cloud.utils.nio.Task; import com.cloud.utils.script.OutputInterpreter; import com.cloud.utils.script.Script; import com.google.common.base.Strings; /** * @config * {@table * || Param Name | Description | Values | Default || * || type | Type of server | Storage / Computing / Routing | No Default || * || workers | # of workers to process the requests | int | 1 || * || host | host to connect to | ip address | localhost || * || port | port to connect to | port number | 8250 || * || instance | Used to allow multiple agents running on the same host | String | none || * } * * For more configuration options, see the individual types. * **/ public class Agent implements HandlerFactory, IAgentControl { private static final Logger s_logger = Logger.getLogger(Agent.class.getName()); public enum ExitStatus { Normal(0), // Normal status = 0. Upgrade(65), // Exiting for upgrade. Configuration(66), // Exiting due to configuration problems. Error(67); // Exiting because of error. int value; ExitStatus(final int value) { this.value = value; } public int value() { return value; } } List<IAgentControlListener> _controlListeners = new ArrayList<IAgentControlListener>(); IAgentShell _shell; NioConnection _connection; ServerResource _resource; Link _link; Long _id; Timer _timer = new Timer("Agent Timer"); List<WatchTask> _watchList = new ArrayList<WatchTask>(); long _sequence = 0; long _lastPingResponseTime = 0; long _pingInterval = 0; AtomicInteger _inProgress = new AtomicInteger(); StartupTask _startup = null; long _startupWaitDefault = 180000; long _startupWait = _startupWaitDefault; boolean _reconnectAllowed = true; //For time sentitive task, e.g. PingTask private final ThreadPoolExecutor _ugentTaskPool; ExecutorService _executor; private String _keystoreSetupPath; private String _keystoreCertImportPath; // for simulator use only public Agent(final IAgentShell shell) { _shell = shell; _link = null; _connection = new NioClient("Agent", _shell.getHost(), _shell.getPort(), _shell.getWorkers(), this); Runtime.getRuntime().addShutdownHook(new ShutdownThread(this)); _ugentTaskPool = new ThreadPoolExecutor(shell.getPingRetries(), 2 * shell.getPingRetries(), 10, TimeUnit.MINUTES, new SynchronousQueue<Runnable>(), new NamedThreadFactory("UgentTask")); _executor = new ThreadPoolExecutor(_shell.getWorkers(), 5 * _shell.getWorkers(), 1, TimeUnit.DAYS, new LinkedBlockingQueue<Runnable>(), new NamedThreadFactory("agentRequest-Handler")); } public Agent(final IAgentShell shell, final int localAgentId, final ServerResource resource) throws ConfigurationException { _shell = shell; _resource = resource; _link = null; resource.setAgentControl(this); final String value = _shell.getPersistentProperty(getResourceName(), "id"); _id = value != null ? Long.parseLong(value) : null; s_logger.info("id is " + (_id != null ? _id : "")); final Map<String, Object> params = PropertiesUtil.toMap(_shell.getProperties()); // merge with properties from command line to let resource access command line parameters for (final Map.Entry<String, Object> cmdLineProp : _shell.getCmdLineProperties().entrySet()) { params.put(cmdLineProp.getKey(), cmdLineProp.getValue()); } if (!_resource.configure(getResourceName(), params)) { throw new ConfigurationException("Unable to configure " + _resource.getName()); } final String host = _shell.getHost(); _connection = new NioClient("Agent", host, _shell.getPort(), _shell.getWorkers(), this); // ((NioClient)_connection).setBindAddress(_shell.getPrivateIp()); s_logger.debug("Adding shutdown hook"); Runtime.getRuntime().addShutdownHook(new ShutdownThread(this)); _ugentTaskPool = new ThreadPoolExecutor(shell.getPingRetries(), 2 * shell.getPingRetries(), 10, TimeUnit.MINUTES, new SynchronousQueue<Runnable>(), new NamedThreadFactory("UgentTask")); _executor = new ThreadPoolExecutor(_shell.getWorkers(), 5 * _shell.getWorkers(), 1, TimeUnit.DAYS, new LinkedBlockingQueue<Runnable>(), new NamedThreadFactory("agentRequest-Handler")); s_logger.info("Agent [id = " + (_id != null ? _id : "new") + " : type = " + getResourceName() + " : zone = " + _shell.getZone() + " : pod = " + _shell.getPod() + " : workers = " + _shell.getWorkers() + " : host = " + host + " : port = " + _shell.getPort()); } public String getVersion() { return _shell.getVersion(); } public String getResourceGuid() { final String guid = _shell.getGuid(); return guid + "-" + getResourceName(); } public String getZone() { return _shell.getZone(); } public String getPod() { return _shell.getPod(); } protected void setLink(final Link link) { _link = link; } public ServerResource getResource() { return _resource; } public BackoffAlgorithm getBackoffAlgorithm() { return _shell.getBackoffAlgorithm(); } public String getResourceName() { return _resource.getClass().getSimpleName(); } public void start() { if (!_resource.start()) { s_logger.error("Unable to start the resource: " + _resource.getName()); throw new CloudRuntimeException("Unable to start the resource: " + _resource.getName()); } _keystoreSetupPath = Script.findScript("scripts/util/", KeyStoreUtils.keyStoreSetupScript); if (_keystoreSetupPath == null) { throw new CloudRuntimeException( String.format("Unable to find the '%s' script", KeyStoreUtils.keyStoreSetupScript)); } _keystoreCertImportPath = Script.findScript("scripts/util/", KeyStoreUtils.keyStoreImportScript); if (_keystoreCertImportPath == null) { throw new CloudRuntimeException( String.format("Unable to find the '%s' script", KeyStoreUtils.keyStoreImportScript)); } try { _connection.start(); } catch (final NioConnectionException e) { s_logger.warn("NIO Connection Exception " + e); s_logger.info( "Attempted to connect to the server, but received an unexpected exception, trying again..."); } while (!_connection.isStartup()) { final String host = _shell.getHost(); _shell.getBackoffAlgorithm().waitBeforeRetry(); _connection = new NioClient("Agent", host, _shell.getPort(), _shell.getWorkers(), this); s_logger.info("Connecting to host:" + host); try { _connection.start(); } catch (final NioConnectionException e) { s_logger.warn("NIO Connection Exception " + e); s_logger.info( "Attempted to connect to the server, but received an unexpected exception, trying again..."); } } } public void stop(final String reason, final String detail) { s_logger.info("Stopping the agent: Reason = " + reason + (detail != null ? ": Detail = " + detail : "")); if (_connection != null) { final ShutdownCommand cmd = new ShutdownCommand(reason, detail); try { if (_link != null) { final Request req = new Request(_id != null ? _id : -1, -1, cmd, false); _link.send(req.toBytes()); } } catch (final ClosedChannelException e) { s_logger.warn("Unable to send: " + cmd.toString()); } catch (final Exception e) { s_logger.warn("Unable to send: " + cmd.toString() + " due to exception: ", e); } s_logger.debug("Sending shutdown to management server"); try { Thread.sleep(1000); } catch (final InterruptedException e) { s_logger.debug("Who the heck interrupted me here?"); } _connection.stop(); _connection = null; } if (_resource != null) { _resource.stop(); _resource = null; } _ugentTaskPool.shutdownNow(); } public Long getId() { return _id; } public void setId(final Long id) { s_logger.info("Set agent id " + id); _id = id; _shell.setPersistentProperty(getResourceName(), "id", Long.toString(id)); } public void scheduleWatch(final Link link, final Request request, final long delay, final long period) { synchronized (_watchList) { if (s_logger.isDebugEnabled()) { s_logger.debug("Adding a watch list"); } final WatchTask task = new WatchTask(link, request, this); _timer.schedule(task, 0, period); _watchList.add(task); } } protected void cancelTasks() { synchronized (_watchList) { for (final WatchTask task : _watchList) { task.cancel(); } if (s_logger.isDebugEnabled()) { s_logger.debug("Clearing watch list: " + _watchList.size()); } _watchList.clear(); } } public synchronized void lockStartupTask(final Link link) { _startup = new StartupTask(link); _timer.schedule(_startup, _startupWait); } public void sendStartup(final Link link) { final StartupCommand[] startup = _resource.initialize(); if (startup != null) { final Command[] commands = new Command[startup.length]; for (int i = 0; i < startup.length; i++) { setupStartupCommand(startup[i]); commands[i] = startup[i]; } final Request request = new Request(_id != null ? _id : -1, -1, commands, false, false); request.setSequence(getNextSequence()); if (s_logger.isDebugEnabled()) { s_logger.debug("Sending Startup: " + request.toString()); } lockStartupTask(link); try { link.send(request.toBytes()); } catch (final ClosedChannelException e) { s_logger.warn("Unable to send reques: " + request.toString()); } } } protected void setupStartupCommand(final StartupCommand startup) { InetAddress addr; try { addr = InetAddress.getLocalHost(); } catch (final UnknownHostException e) { s_logger.warn("unknow host? ", e); throw new CloudRuntimeException("Cannot get local IP address"); } final Script command = new Script("hostname", 500, s_logger); final OutputInterpreter.OneLineParser parser = new OutputInterpreter.OneLineParser(); final String result = command.execute(parser); final String hostname = result == null ? parser.getLine() : addr.toString(); startup.setId(getId()); if (startup.getName() == null) { startup.setName(hostname); } startup.setDataCenter(getZone()); startup.setPod(getPod()); startup.setGuid(getResourceGuid()); startup.setResourceName(getResourceName()); startup.setVersion(getVersion()); } @Override public Task create(final Task.Type type, final Link link, final byte[] data) { return new ServerHandler(type, link, data); } protected void reconnect(final Link link) { if (!_reconnectAllowed) { return; } synchronized (this) { if (_startup != null) { _startup.cancel(); _startup = null; } } link.close(); link.terminated(); setLink(null); cancelTasks(); _resource.disconnected(); int inProgress = 0; do { _shell.getBackoffAlgorithm().waitBeforeRetry(); s_logger.info("Lost connection to the server. Dealing with the remaining commands..."); inProgress = _inProgress.get(); if (inProgress > 0) { s_logger.info("Cannot connect because we still have " + inProgress + " commands in progress."); } } while (inProgress > 0); _connection.stop(); try { _connection.cleanUp(); } catch (final IOException e) { s_logger.warn("Fail to clean up old connection. " + e); } while (_connection.isStartup()) { _shell.getBackoffAlgorithm().waitBeforeRetry(); } final String host = _shell.getHost(); do { _connection = new NioClient("Agent", host, _shell.getPort(), _shell.getWorkers(), this); s_logger.info("Reconnecting to host:" + host); try { _connection.start(); } catch (final NioConnectionException e) { s_logger.warn("NIO Connection Exception " + e); s_logger.info( "Attempted to connect to the server, but received an unexpected exception, trying again..."); _connection.stop(); try { _connection.cleanUp(); } catch (final IOException ex) { s_logger.warn("Fail to clean up old connection. " + ex); } } _shell.getBackoffAlgorithm().waitBeforeRetry(); } while (!_connection.isStartup()); s_logger.info("Connected to the server"); } public void processStartupAnswer(final Answer answer, final Response response, final Link link) { boolean cancelled = false; synchronized (this) { if (_startup != null) { _startup.cancel(); _startup = null; } else { cancelled = true; } } final StartupAnswer startup = (StartupAnswer) answer; if (!startup.getResult()) { s_logger.error("Not allowed to connect to the server: " + answer.getDetails()); System.exit(1); } if (cancelled) { s_logger.warn("Threw away a startup answer because we're reconnecting."); return; } s_logger.info("Proccess agent startup answer, agent id = " + startup.getHostId()); setId(startup.getHostId()); _pingInterval = (long) startup.getPingInterval() * 1000; // change to ms. setLastPingResponseTime(); scheduleWatch(link, response, _pingInterval, _pingInterval); _ugentTaskPool.setKeepAliveTime(2 * _pingInterval, TimeUnit.MILLISECONDS); s_logger.info("Startup Response Received: agent id = " + getId()); } protected void processRequest(final Request request, final Link link) { boolean requestLogged = false; Response response = null; try { final Command[] cmds = request.getCommands(); final Answer[] answers = new Answer[cmds.length]; for (int i = 0; i < cmds.length; i++) { final Command cmd = cmds[i]; Answer answer; try { if (cmd.getContextParam("logid") != null) { MDC.put("logcontextid", cmd.getContextParam("logid")); } if (s_logger.isDebugEnabled()) { if (!requestLogged) // ensures request is logged only once per method call { final String requestMsg = request.toString(); if (requestMsg != null) { s_logger.debug("Request:" + requestMsg); } requestLogged = true; } s_logger.debug("Processing command: " + cmd.toString()); } if (cmd instanceof CronCommand) { final CronCommand watch = (CronCommand) cmd; scheduleWatch(link, request, (long) watch.getInterval() * 1000, watch.getInterval() * 1000); answer = new Answer(cmd, true, null); } else if (cmd instanceof ShutdownCommand) { final ShutdownCommand shutdown = (ShutdownCommand) cmd; s_logger.debug("Received shutdownCommand, due to: " + shutdown.getReason()); cancelTasks(); _reconnectAllowed = false; answer = new Answer(cmd, true, null); } else if (cmd instanceof ReadyCommand && ((ReadyCommand) cmd).getDetails() != null) { s_logger.debug("Not ready to connect to mgt server: " + ((ReadyCommand) cmd).getDetails()); System.exit(1); return; } else if (cmd instanceof MaintainCommand) { s_logger.debug("Received maintainCommand"); cancelTasks(); _reconnectAllowed = false; answer = new MaintainAnswer((MaintainCommand) cmd); } else if (cmd instanceof AgentControlCommand) { answer = null; synchronized (_controlListeners) { for (final IAgentControlListener listener : _controlListeners) { answer = listener.processControlRequest(request, (AgentControlCommand) cmd); if (answer != null) { break; } } } if (answer == null) { s_logger.warn("No handler found to process cmd: " + cmd.toString()); answer = new AgentControlAnswer(cmd); } } else if (cmd instanceof SetupKeyStoreCommand && ((SetupKeyStoreCommand) cmd).isHandleByAgent()) { answer = setupAgentKeystore((SetupKeyStoreCommand) cmd); } else if (cmd instanceof SetupCertificateCommand && ((SetupCertificateCommand) cmd).isHandleByAgent()) { answer = setupAgentCertificate((SetupCertificateCommand) cmd); } else { if (cmd instanceof ReadyCommand) { processReadyCommand(cmd); } _inProgress.incrementAndGet(); try { answer = _resource.executeRequest(cmd); } finally { _inProgress.decrementAndGet(); } if (answer == null) { s_logger.debug("Response: unsupported command" + cmd.toString()); answer = Answer.createUnsupportedCommandAnswer(cmd); } } } catch (final Throwable th) { s_logger.warn("Caught: ", th); final StringWriter writer = new StringWriter(); th.printStackTrace(new PrintWriter(writer)); answer = new Answer(cmd, false, writer.toString()); } answers[i] = answer; if (!answer.getResult() && request.stopOnError()) { for (i++; i < cmds.length; i++) { answers[i] = new Answer(cmds[i], false, "Stopped by previous failure"); } break; } } response = new Response(request, answers); } finally { if (s_logger.isDebugEnabled()) { final String responseMsg = response.toString(); if (responseMsg != null) { s_logger.debug(response.toString()); } } if (response != null) { try { link.send(response.toBytes()); } catch (final ClosedChannelException e) { s_logger.warn("Unable to send response: " + response.toString()); } } } } public Answer setupAgentKeystore(final SetupKeyStoreCommand cmd) { final String keyStorePassword = cmd.getKeystorePassword(); final long validityDays = cmd.getValidityDays(); s_logger.debug("Setting up agent keystore file and generating CSR"); final File agentFile = PropertiesUtil.findConfigFile("agent.properties"); if (agentFile == null) { return new Answer(cmd, false, "Failed to find agent.properties file"); } final String keyStoreFile = agentFile.getParent() + "/" + KeyStoreUtils.defaultKeystoreFile; final String csrFile = agentFile.getParent() + "/" + KeyStoreUtils.defaultCsrFile; String storedPassword = _shell.getPersistentProperty(null, KeyStoreUtils.passphrasePropertyName); if (Strings.isNullOrEmpty(storedPassword)) { storedPassword = keyStorePassword; _shell.setPersistentProperty(null, KeyStoreUtils.passphrasePropertyName, storedPassword); } Script script = new Script(_keystoreSetupPath, 60000, s_logger); script.add(agentFile.getAbsolutePath()); script.add(keyStoreFile); script.add(storedPassword); script.add(String.valueOf(validityDays)); script.add(csrFile); String result = script.execute(); if (result != null) { throw new CloudRuntimeException("Unable to setup keystore file"); } final String csrString; try { csrString = FileUtils.readFileToString(new File(csrFile), Charset.defaultCharset()); } catch (IOException e) { throw new CloudRuntimeException("Unable to read generated CSR file", e); } return new SetupKeystoreAnswer(csrString); } private Answer setupAgentCertificate(final SetupCertificateCommand cmd) { final String certificate = cmd.getCertificate(); final String privateKey = cmd.getPrivateKey(); final String caCertificates = cmd.getCaCertificates(); s_logger.debug("Importing received certificate to agent's keystore"); final File agentFile = PropertiesUtil.findConfigFile("agent.properties"); if (agentFile == null) { return new Answer(cmd, false, "Failed to find agent.properties file"); } final String keyStoreFile = agentFile.getParent() + "/" + KeyStoreUtils.defaultKeystoreFile; final String certFile = agentFile.getParent() + "/" + KeyStoreUtils.defaultCertFile; final String privateKeyFile = agentFile.getParent() + "/" + KeyStoreUtils.defaultPrivateKeyFile; final String caCertFile = agentFile.getParent() + "/" + KeyStoreUtils.defaultCaCertFile; try { FileUtils.writeStringToFile(new File(certFile), certificate, Charset.defaultCharset()); FileUtils.writeStringToFile(new File(caCertFile), caCertificates, Charset.defaultCharset()); s_logger.debug("Saved received client certificate to: " + certFile); } catch (IOException e) { throw new CloudRuntimeException("Unable to save received agent client and ca certificates", e); } Script script = new Script(_keystoreCertImportPath, 60000, s_logger); script.add(agentFile.getAbsolutePath()); script.add(keyStoreFile); script.add(KeyStoreUtils.agentMode); script.add(certFile); script.add(""); script.add(caCertFile); script.add(""); script.add(privateKeyFile); script.add(privateKey); String result = script.execute(); if (result != null) { throw new CloudRuntimeException("Unable to import certificate into keystore file"); } return new SetupCertificateAnswer(true); } public void processResponse(final Response response, final Link link) { final Answer answer = response.getAnswer(); if (s_logger.isDebugEnabled()) { s_logger.debug("Received response: " + response.toString()); } if (answer instanceof StartupAnswer) { processStartupAnswer(answer, response, link); } else if (answer instanceof AgentControlAnswer) { // Notice, we are doing callback while holding a lock! synchronized (_controlListeners) { for (final IAgentControlListener listener : _controlListeners) { listener.processControlResponse(response, (AgentControlAnswer) answer); } } } else { setLastPingResponseTime(); } } public void processReadyCommand(final Command cmd) { final ReadyCommand ready = (ReadyCommand) cmd; s_logger.info("Proccess agent ready command, agent id = " + ready.getHostId()); if (ready.getHostId() != null) { setId(ready.getHostId()); } s_logger.info("Ready command is processed: agent id = " + getId()); } public void processOtherTask(final Task task) { final Object obj = task.get(); if (obj instanceof Response) { if (System.currentTimeMillis() - _lastPingResponseTime > _pingInterval * _shell.getPingRetries()) { s_logger.error("Ping Interval has gone past " + _pingInterval * _shell.getPingRetries() + ". Won't reconnect to mgt server, as connection is still alive"); return; } final PingCommand ping = _resource.getCurrentStatus(getId()); final Request request = new Request(_id, -1, ping, false); request.setSequence(getNextSequence()); if (s_logger.isDebugEnabled()) { s_logger.debug("Sending ping: " + request.toString()); } try { task.getLink().send(request.toBytes()); //if i can send pingcommand out, means the link is ok setLastPingResponseTime(); } catch (final ClosedChannelException e) { s_logger.warn("Unable to send request: " + request.toString()); } } else if (obj instanceof Request) { final Request req = (Request) obj; final Command command = req.getCommand(); if (command.getContextParam("logid") != null) { MDC.put("logcontextid", command.getContextParam("logid")); } Answer answer = null; _inProgress.incrementAndGet(); try { answer = _resource.executeRequest(command); } finally { _inProgress.decrementAndGet(); } if (answer != null) { final Response response = new Response(req, answer); if (s_logger.isDebugEnabled()) { s_logger.debug("Watch Sent: " + response.toString()); } try { task.getLink().send(response.toBytes()); } catch (final ClosedChannelException e) { s_logger.warn("Unable to send response: " + response.toString()); } } } else { s_logger.warn("Ignoring an unknown task"); } } public synchronized void setLastPingResponseTime() { _lastPingResponseTime = System.currentTimeMillis(); } protected synchronized long getNextSequence() { return _sequence++; } @Override public void registerControlListener(final IAgentControlListener listener) { synchronized (_controlListeners) { _controlListeners.add(listener); } } @Override public void unregisterControlListener(final IAgentControlListener listener) { synchronized (_controlListeners) { _controlListeners.remove(listener); } } @Override public AgentControlAnswer sendRequest(final AgentControlCommand cmd, final int timeoutInMilliseconds) throws AgentControlChannelException { final Request request = new Request(getId(), -1, new Command[] { cmd }, true, false); request.setSequence(getNextSequence()); final AgentControlListener listener = new AgentControlListener(request); registerControlListener(listener); try { postRequest(request); synchronized (listener) { try { listener.wait(timeoutInMilliseconds); } catch (final InterruptedException e) { s_logger.warn("sendRequest is interrupted, exit waiting"); } } return listener.getAnswer(); } finally { unregisterControlListener(listener); } } @Override public void postRequest(final AgentControlCommand cmd) throws AgentControlChannelException { final Request request = new Request(getId(), -1, new Command[] { cmd }, true, false); request.setSequence(getNextSequence()); postRequest(request); } private void postRequest(final Request request) throws AgentControlChannelException { if (_link != null) { try { _link.send(request.toBytes()); } catch (final ClosedChannelException e) { s_logger.warn("Unable to post agent control reques: " + request.toString()); throw new AgentControlChannelException( "Unable to post agent control request due to " + e.getMessage()); } } else { throw new AgentControlChannelException("Unable to post agent control request as link is not available"); } } public class AgentControlListener implements IAgentControlListener { private AgentControlAnswer _answer; private final Request _request; public AgentControlListener(final Request request) { _request = request; } public AgentControlAnswer getAnswer() { return _answer; } @Override public Answer processControlRequest(final Request request, final AgentControlCommand cmd) { return null; } @Override public void processControlResponse(final Response response, final AgentControlAnswer answer) { if (_request.getSequence() == response.getSequence()) { _answer = answer; synchronized (this) { notifyAll(); } } } } protected class ShutdownThread extends Thread { Agent _agent; public ShutdownThread(final Agent agent) { super("AgentShutdownThread"); _agent = agent; } @Override public void run() { _agent.stop(ShutdownCommand.Requested, null); } } public class WatchTask extends ManagedContextTimerTask { protected Request _request; protected Agent _agent; protected Link _link; public WatchTask(final Link link, final Request request, final Agent agent) { super(); _request = request; _link = link; _agent = agent; } @Override protected void runInContext() { if (s_logger.isTraceEnabled()) { s_logger.trace("Scheduling " + (_request instanceof Response ? "Ping" : "Watch Task")); } try { if (_request instanceof Response) { _ugentTaskPool.submit(new ServerHandler(Task.Type.OTHER, _link, _request)); } else { _link.schedule(new ServerHandler(Task.Type.OTHER, _link, _request)); } } catch (final ClosedChannelException e) { s_logger.warn("Unable to schedule task because channel is closed"); } } } public class StartupTask extends ManagedContextTimerTask { protected Link _link; protected volatile boolean cancelled = false; public StartupTask(final Link link) { s_logger.debug("Startup task created"); _link = link; } @Override public synchronized boolean cancel() { // TimerTask.cancel may fail depends on the calling context if (!cancelled) { cancelled = true; _startupWait = _startupWaitDefault; s_logger.debug("Startup task cancelled"); return super.cancel(); } return true; } @Override protected synchronized void runInContext() { if (!cancelled) { if (s_logger.isInfoEnabled()) { s_logger.info("The startup command is now cancelled"); } cancelled = true; _startup = null; _startupWait = _startupWaitDefault * 2; reconnect(_link); } } } public class AgentRequestHandler extends Task { public AgentRequestHandler(final Task.Type type, final Link link, final Request req) { super(type, link, req); } @Override protected void doTask(final Task task) throws TaskExecutionException { final Request req = (Request) get(); if (!(req instanceof Response)) { processRequest(req, task.getLink()); } } } public class ServerHandler extends Task { public ServerHandler(final Task.Type type, final Link link, final byte[] data) { super(type, link, data); } public ServerHandler(final Task.Type type, final Link link, final Request req) { super(type, link, req); } @Override public void doTask(final Task task) throws TaskExecutionException { if (task.getType() == Task.Type.CONNECT) { _shell.getBackoffAlgorithm().reset(); setLink(task.getLink()); sendStartup(task.getLink()); } else if (task.getType() == Task.Type.DATA) { Request request; try { request = Request.parse(task.getData()); if (request instanceof Response) { //It's for pinganswer etc, should be processed immediately. processResponse((Response) request, task.getLink()); } else { //put the requests from mgt server into another thread pool, as the request may take a longer time to finish. Don't block the NIO main thread pool //processRequest(request, task.getLink()); _executor.submit(new AgentRequestHandler(getType(), getLink(), request)); } } catch (final ClassNotFoundException e) { s_logger.error("Unable to find this request "); } catch (final Exception e) { s_logger.error("Error parsing task", e); } } else if (task.getType() == Task.Type.DISCONNECT) { reconnect(task.getLink()); return; } else if (task.getType() == Task.Type.OTHER) { processOtherTask(task); } } } }