Java tutorial
/* * Jopr Management Platform * Copyright (C) 2005-2008 Red Hat, Inc. * All rights reserved. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License, version 2, as * published by the Free Software Foundation, and/or the GNU Lesser * General Public License, version 2.1, also as published by the Free * Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License and the GNU Lesser General Public License * for more details. * * You should have received a copy of the GNU General Public License * and the GNU Lesser General Public License along with this program; * if not, write to the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ package org.rhq.plugins.jbossas; import java.io.File; import java.util.List; import java.util.StringTokenizer; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.mc4j.ems.connection.EmsConnection; import org.mc4j.ems.connection.bean.EmsBean; import org.mc4j.ems.connection.bean.operation.EmsOperation; import org.mc4j.ems.connection.bean.parameter.EmsParameter; import org.rhq.core.domain.configuration.Configuration; import org.rhq.core.domain.configuration.PropertySimple; import org.rhq.core.domain.measurement.AvailabilityType; import org.rhq.core.pluginapi.operation.OperationResult; import org.rhq.core.pluginapi.util.ProcessExecutionUtility; import org.rhq.core.system.ProcessExecution; import org.rhq.core.system.ProcessExecutionResults; import org.rhq.core.system.SystemInfo; /** * Handles performing operations on a JBossAS instance. * * @author Ian Springer * @author Jason Dobies * @author Jay Shaughnessy */ public class JBossASServerOperationsDelegate { /** max amount of time to wait for server to show as unavailable after executing stop - in milliseconds */ private static long STOP_WAIT_MAX = 1000L * 150; // 2.5 minutes /** amount of time to wait between availability checks when performing a stop - in milliseconds */ private static final long STOP_WAIT_INTERVAL = 1000L * 10; // 10 seconds /** amount of time to wait for stop to complete after the loop that checks for DOWN availability terminates - * in milliseconds */ private static final long STOP_WAIT_FINAL = 1000L * 30; // 30 seconds /** max amount of time to wait for start to complete - in milliseconds */ private static long START_WAIT_MAX = 1000L * 300; // 5 minutes /** amount of time to wait between availability checks when performing a start - in milliseconds */ private static final long START_WAIT_INTERVAL = 1000L * 10; // 10 seconds private final Log log = LogFactory.getLog(JBossASServerOperationsDelegate.class); private static final String SEPARATOR = "\n-----------------------\n"; // Attributes -------------------------------------------- /** * Server component against which the operations are being performed. */ private JBossASServerComponent serverComponent; /** * Passed in from the resource context for making process calls. */ private SystemInfo systemInfo; // Constructors -------------------------------------------- public JBossASServerOperationsDelegate(JBossASServerComponent serverComponent, SystemInfo systemInfo) { this.serverComponent = serverComponent; this.systemInfo = systemInfo; } // Public -------------------------------------------- /** * Performs the specified operation. The result of the operation will be indicated in the return. If there is an * error, an <code>RuntimeException</code> will be thrown. * * @param operation the operation to perform * @param parameters parameters to the operation call * * @return if successful, the result object will contain a success message * * @throws RuntimeException if any errors occur while trying to perform the operation */ public OperationResult invoke(JBossASServerSupportedOperations operation, Configuration parameters) throws InterruptedException { String message = null; switch (operation) { case RESTART: { message = restart(); break; } case SHUTDOWN: { message = shutdown(); break; } case START: { message = start(); break; } } OperationResult result = new OperationResult(message); return result; } // Private -------------------------------------------- /** * Starts the underlying AS server. * * @return success message if no errors are encountered * @throws InterruptedException if the plugin container stops this operation while its executing */ private String start() throws InterruptedException { Configuration pluginConfiguration = this.serverComponent.getPluginConfiguration(); File startScriptFile = this.serverComponent.getStartScriptPath(); validateScriptFile(startScriptFile, JBossASServerComponent.START_SCRIPT_CONFIG_PROP); String prefix = pluginConfiguration.getSimple(JBossASServerComponent.SCRIPT_PREFIX_CONFIG_PROP) .getStringValue(); String configName = this.serverComponent.getConfigurationSet(); String bindingAddress = pluginConfiguration.getSimple(JBossASServerComponent.BINDING_ADDRESS_CONFIG_PROP) .getStringValue(); String configArgument = "-c" + configName; String bindingAddressArgument = null; if (bindingAddress != null) bindingAddressArgument = "-b" + bindingAddress; ProcessExecution processExecution; // prefix is either null or contains ONLY whitespace characters if (prefix == null || prefix.replaceAll("\\s", "").equals("")) { processExecution = ProcessExecutionUtility.createProcessExecution(startScriptFile); processExecution.getArguments().add("-c"); processExecution.getArguments().add(configName); if (bindingAddressArgument != null) { processExecution.getArguments().add("-b"); processExecution.getArguments().add(bindingAddress); } } else { // The process execution should be tied to the process represented as the prefix. If there are any other // tokens in the prefix, consider them arguments to the prefix process. StringTokenizer prefixTokenizer = new StringTokenizer(prefix); String processName = prefixTokenizer.nextToken(); File prefixProcess = new File(processName); processExecution = ProcessExecutionUtility.createProcessExecution(prefixProcess); while (prefixTokenizer.hasMoreTokens()) { String prefixArgument = prefixTokenizer.nextToken(); processExecution.getArguments().add(prefixArgument); } // Assemble the AS start script and its prefixes as one argument to the prefix String startScriptArgument = startScriptFile.getAbsolutePath(); startScriptArgument += " " + configArgument; if (bindingAddressArgument != null) { startScriptArgument += " " + bindingAddressArgument; } processExecution.getArguments().add(startScriptArgument); } initProcessExecution(processExecution, startScriptFile); long start = System.currentTimeMillis(); if (log.isDebugEnabled()) { log.debug("About to execute the following process: [" + processExecution + "]"); } ProcessExecutionResults results = this.systemInfo.executeProcess(processExecution); logExecutionResults(results); AvailabilityType avail; if (results.getError() == null) { avail = waitForServerToStart(start); } else { log.error("Error from process execution while starting the AS instance. Exit code [" + results.getExitCode() + "]", results.getError()); avail = this.serverComponent.getAvailability(); } // If, after the loop, the Server is still down, consider the start to be a failure. if (avail == AvailabilityType.DOWN) { throw new RuntimeException("Server failed to start: " + results.getCapturedOutput()); } else { return "Server has been started."; } } private void initProcessExecution(ProcessExecution processExecution, File scriptFile) { // NOTE: For both run.bat and shutdown.bat, the current working dir must be set to the script's parent dir // (e.g. ${JBOSS_HOME}/bin) for the script to work. processExecution.setWorkingDirectory(scriptFile.getParent()); // Both scripts require the JAVA_HOME env var to be set. File javaHomeDir = this.serverComponent.getJavaHomePath(); if (javaHomeDir == null) { throw new IllegalStateException("The '" + JBossASServerComponent.JAVA_HOME_PATH_CONFIG_PROP + "' connection property must be set in order to start or stop JBossAS via script."); } this.serverComponent.validateJavaHomePathProperty(); processExecution.getEnvironmentVariables().put("JAVA_HOME", javaHomeDir.getPath()); processExecution.setCaptureOutput(true); processExecution.setWaitForCompletion(1000L); // 1 second // TODO: Should we wait longer than one second? processExecution.setKillOnTimeout(false); } /** * Shuts down the server by dispatching to shutdown via script or JMX. Waits until the server is down. * @return The result of the shutdown operation - is successful */ private String shutdown() { JBossASServerShutdownMethod shutdownMethod = Enum.valueOf(JBossASServerShutdownMethod.class, this.serverComponent.getPluginConfiguration() .getSimple(JBossASServerComponent.SHUTDOWN_METHOD_CONFIG_PROP).getStringValue()); String result = JBossASServerShutdownMethod.JMX.equals(shutdownMethod) ? shutdownViaJmx() : shutdownViaScript(); AvailabilityType avail = waitForServerToShutdown(); if (avail == AvailabilityType.UP) { throw new RuntimeException("Server failed to shutdown"); } else { return result; } } /** * Shuts down the AS server using a shutdown script. * * @return success message if no errors are encountered */ private String shutdownViaScript() { Configuration pluginConfiguration = this.serverComponent.getPluginConfiguration(); File shutdownScriptFile = this.serverComponent.getShutdownScriptPath(); validateScriptFile(shutdownScriptFile, JBossASServerComponent.SHUTDOWN_SCRIPT_CONFIG_PROP); String prefix = pluginConfiguration.getSimple(JBossASServerComponent.SCRIPT_PREFIX_CONFIG_PROP) .getStringValue(); ProcessExecution processExecution = ProcessExecutionUtility.createProcessExecution(prefix, shutdownScriptFile); initProcessExecution(processExecution, shutdownScriptFile); String server = pluginConfiguration.getSimple(JBossASServerComponent.NAMING_URL_CONFIG_PROP) .getStringValue(); if (server != null) { processExecution.getArguments().add("--server=" + server); } String user = pluginConfiguration.getSimple(JBossASServerComponent.PRINCIPAL_CONFIG_PROP).getStringValue(); if (user != null) { processExecution.getArguments().add("--user=" + user); } String password = pluginConfiguration.getSimple(JBossASServerComponent.CREDENTIALS_CONFIG_PROP) .getStringValue(); if (password != null) { processExecution.getArguments().add("--password=" + password); } processExecution.getArguments().add("--shutdown"); /* This tells shutdown.bat not to call the Windows PAUSE command, which * would cause the script to hang indefinitely waiting for input. * noinspection ConstantConditions */ processExecution.getEnvironmentVariables().put("NOPAUSE", "1"); if (log.isDebugEnabled()) { log.debug("About to execute the following process: [" + processExecution + "]"); } ProcessExecutionResults results = this.systemInfo.executeProcess(processExecution); logExecutionResults(results); if (results.getError() != null) { throw new RuntimeException("Error executing shutdown script while stopping AS instance. Exit code [" + results.getExitCode() + "]", results.getError()); } return "Server has been shut down."; } private void logExecutionResults(ProcessExecutionResults results) { // Always log the output at info level. On Unix we could switch depending on a exitCode being !=0, but ... log.info("Exit code from process execution: " + results.getExitCode()); log.info("Output from process execution: " + SEPARATOR + results.getCapturedOutput() + SEPARATOR); } /** * Shuts down the AS server via a JMX call. * * @return success message if no errors are encountered */ private String shutdownViaJmx() { Configuration pluginConfiguration = this.serverComponent.getPluginConfiguration(); String mbeanName = pluginConfiguration.getSimple(JBossASServerComponent.SHUTDOWN_MBEAN_CONFIG_PROP) .getStringValue(); String operationName = pluginConfiguration .getSimple(JBossASServerComponent.SHUTDOWN_MBEAN_OPERATION_CONFIG_PROP).getStringValue(); EmsConnection connection = this.serverComponent.getEmsConnection(); if (connection == null) { throw new RuntimeException("Can not connect to the server"); } EmsBean bean = connection.getBean(mbeanName); EmsOperation operation = bean.getOperation(operationName); /* * Now see if we got the 'real' method (the one with no param) or the overloaded one. * This is a workaround for a bug in EMS that prevents finding operations with same name * and different signature. * http://sourceforge.net/tracker/index.php?func=detail&aid=2007692&group_id=60228&atid=493495 * * In addition, as we offer the user to specify any MBean and any method, we'd need a * clever way for the user to specify parameters anyway. */ List<EmsParameter> params = operation.getParameters(); int count = params.size(); if (count == 0) operation.invoke(new Object[0]); else { // overloaded operation operation.invoke(new Object[] { 0 }); // return code of 0 } return "Server has been shut down."; } private void validateScriptFile(File scriptFile, String scriptPropertyName) { if (!scriptFile.exists()) { throw new RuntimeException("Script (" + scriptFile + ") specified via '" + scriptPropertyName + "' connection property does not exist."); } if (scriptFile.isDirectory()) { throw new RuntimeException("Script (" + scriptFile + ") specified via '" + scriptPropertyName + "' connection property is a directory, not a file."); } } /** * Restart the server by first trying a shutdown and then a start. This is fail fast. * @return A success message on success */ private String restart() { try { shutdown(); } catch (Exception e) { throw new RuntimeException("Shutdown may have failed: " + e); } try { // Perform the restart. start(); } catch (Exception e) { throw new RuntimeException("Re-Startup may have failed: " + e); } return "Server has been restarted."; } private AvailabilityType waitForServerToStart(long start) throws InterruptedException { AvailabilityType avail; //detect whether startWaitMax property has been set. Configuration pluginConfig = serverComponent.getPluginConfiguration(); PropertySimple property = pluginConfig.getSimple(JBossASServerComponent.START_WAIT_MAX_PROP); //if set and valid, update startWaitMax value if ((property != null) && (property.getIntegerValue() != null)) { int newValue = property.getIntegerValue(); if (newValue >= 1) { START_WAIT_MAX = 1000L * 60 * newValue; } } while (((avail = this.serverComponent.getAvailability()) == AvailabilityType.DOWN) && (System.currentTimeMillis() < (start + START_WAIT_MAX))) { try { Thread.sleep(START_WAIT_INTERVAL); } catch (InterruptedException e) { // ignore } } return avail; } private AvailabilityType waitForServerToShutdown() { //detect whether stopWaitMax property has been set. Configuration pluginConfig = serverComponent.getPluginConfiguration(); PropertySimple property = pluginConfig.getSimple(JBossASServerComponent.STOP_WAIT_MAX_PROP); //if set and valid, update startWaitMax value if ((property != null) && (property.getIntegerValue() != null)) { int newValue = property.getIntegerValue(); if (newValue >= 1) { STOP_WAIT_MAX = 1000L * 60 * newValue; } } for (long wait = 0L; (wait < STOP_WAIT_MAX) && (AvailabilityType.UP == this.serverComponent.getAvailability()); wait += STOP_WAIT_INTERVAL) { try { Thread.sleep(STOP_WAIT_INTERVAL); } catch (InterruptedException e) { // ignore } } // After the server shows unavailable, wait a little longer to hopefully ensure shutdown is complete. try { Thread.sleep(STOP_WAIT_FINAL); } catch (InterruptedException e) { // ignore } return this.serverComponent.getAvailability(); } }