/*
* Copyright 2012 LinkedIn, Inc
*
* Licensed 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 azkaban.webapp;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.lang.management.ManagementFactory;
import java.lang.reflect.Constructor;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.TimeZone;
import javax.management.MBeanInfo;
import javax.management.MBeanServer;
import javax.management.ObjectName;
import org.apache.commons.lang.StringUtils;
import org.apache.log4j.Logger;
import org.apache.velocity.app.VelocityEngine;
import org.apache.velocity.runtime.log.Log4JLogChute;
import org.apache.velocity.runtime.resource.loader.ClasspathResourceLoader;
import org.apache.velocity.runtime.resource.loader.JarResourceLoader;
import org.joda.time.DateTimeZone;
import org.mortbay.jetty.Server;
import org.mortbay.jetty.bio.SocketConnector;
import org.mortbay.jetty.security.SslSocketConnector;
import org.mortbay.jetty.servlet.Context;
import org.mortbay.jetty.servlet.DefaultServlet;
import org.mortbay.jetty.servlet.ServletHolder;
import org.mortbay.thread.QueuedThreadPool;
import azkaban.database.AzkabanDatabaseSetup;
import azkaban.executor.ExecutorManager;
import azkaban.executor.JdbcExecutorLoader;
import azkaban.jmx.JmxExecutorManager;
import azkaban.jmx.JmxJettyServer;
import azkaban.jmx.JmxSLAManager;
import azkaban.jmx.JmxScheduler;
import azkaban.project.JdbcProjectLoader;
import azkaban.project.ProjectManager;
import azkaban.scheduler.JdbcScheduleLoader;
import azkaban.scheduler.ScheduleManager;
import azkaban.sla.JdbcSLALoader;
import azkaban.sla.SLAManager;
import azkaban.sla.SLAManagerException;
import azkaban.user.UserManager;
import azkaban.user.XmlUserManager;
import azkaban.utils.FileIOUtils;
import azkaban.utils.Props;
import azkaban.utils.PropsUtils;
import azkaban.utils.Utils;
import azkaban.webapp.servlet.AzkabanServletContextListener;
import azkaban.webapp.servlet.AbstractAzkabanServlet;
import azkaban.webapp.servlet.ExecutorServlet;
import azkaban.webapp.servlet.JMXHttpServlet;
import azkaban.webapp.servlet.ScheduleServlet;
import azkaban.webapp.servlet.HistoryServlet;
import azkaban.webapp.servlet.IndexServlet;
import azkaban.webapp.servlet.ProjectManagerServlet;
import azkaban.webapp.servlet.ViewerPlugin;
import azkaban.webapp.session.SessionCache;
/**
* The Azkaban Jetty server class
*
* Global azkaban properties for setup. All of them are optional unless
* otherwise marked: azkaban.name - The displayed name of this instance.
* azkaban.label - Short descriptor of this Azkaban instance. azkaban.color -
* Theme color azkaban.temp.dir - Temp dir used by Azkaban for various file
* uses. web.resource.dir - The directory that contains the static web files.
* default.timezone.id - The timezone code. I.E. America/Los Angeles
*
* user.manager.class - The UserManager class used for the user manager. Default
* is XmlUserManager. project.manager.class - The ProjectManager to load
* projects project.global.properties - The base properties inherited by all
* projects and jobs
*
* jetty.maxThreads - # of threads for jetty jetty.ssl.port - The ssl port used
* for sessionizing. jetty.keystore - Jetty keystore . jetty.keypassword - Jetty
* keystore password jetty.truststore - Jetty truststore jetty.trustpassword -
* Jetty truststore password
*/
public class AzkabanWebServer extends AzkabanServer {
private static final Logger logger = Logger.getLogger(AzkabanWebServer.class);
public static final String AZKABAN_HOME = "AZKABAN_HOME";
public static final String DEFAULT_CONF_PATH = "conf";
public static final String AZKABAN_PROPERTIES_FILE = "azkaban.properties";
public static final String AZKABAN_PRIVATE_PROPERTIES_FILE = "azkaban.private.properties";
private static final int MAX_FORM_CONTENT_SIZE = 10*1024*1024;
private static final int MAX_HEADER_BUFFER_SIZE = 10*1024*1024;
private static AzkabanWebServer app;
private static final String DEFAULT_TIMEZONE_ID = "default.timezone.id";
private static final int DEFAULT_PORT_NUMBER = 8081;
private static final int DEFAULT_SSL_PORT_NUMBER = 8443;
private static final int DEFAULT_THREAD_NUMBER = 20;
private static final String VELOCITY_DEV_MODE_PARAM = "velocity.dev.mode";
private static final String USER_MANAGER_CLASS_PARAM = "user.manager.class";
private static final String DEFAULT_STATIC_DIR = "";
private final VelocityEngine velocityEngine;
private final Server server;
private UserManager userManager;
private ProjectManager projectManager;
private ExecutorManager executorManager;
private ScheduleManager scheduleManager;
private SLAManager slaManager;
private final ClassLoader baseClassLoader;
private Props props;
private SessionCache sessionCache;
private File tempDir;
private List<ViewerPlugin> viewerPlugins;
private MBeanServer mbeanServer;
private ArrayList<ObjectName> registeredMBeans = new ArrayList<ObjectName>();
/**
* Constructor usually called by tomcat AzkabanServletContext to create the
* initial server
*/
public AzkabanWebServer() throws Exception {
this(null, loadConfigurationFromAzkabanHome());
}
/**
* Constructor
*/
public AzkabanWebServer(Server server, Props props) throws Exception {
this.props = props;
this.server = server;
velocityEngine = configureVelocityEngine(props.getBoolean(VELOCITY_DEV_MODE_PARAM, false));
sessionCache = new SessionCache(props);
userManager = loadUserManager(props);
projectManager = loadProjectManager(props);
executorManager = loadExecutorManager(props);
slaManager = loadSLAManager(props);
scheduleManager = loadScheduleManager(executorManager, slaManager, props);
baseClassLoader = getBaseClassloader();
tempDir = new File(props.getString("azkaban.temp.dir", "temp"));
// Setup time zone
if (props.containsKey(DEFAULT_TIMEZONE_ID)) {
String timezone = props.getString(DEFAULT_TIMEZONE_ID);
TimeZone.setDefault(TimeZone.getTimeZone(timezone));
DateTimeZone.setDefault(DateTimeZone.forID(timezone));
logger.info("Setting timezone to " + timezone);
}
configureMBeanServer();
}
private void setViewerPlugins(List<ViewerPlugin> viewerPlugins) {
this.viewerPlugins = viewerPlugins;
}
private UserManager loadUserManager(Props props) {
Class<?> userManagerClass = props.getClass(USER_MANAGER_CLASS_PARAM, null);
logger.info("Loading user manager class " + userManagerClass.getName());
UserManager manager = null;
if (userManagerClass != null && userManagerClass.getConstructors().length > 0) {
try {
Constructor<?> userManagerConstructor = userManagerClass.getConstructor(Props.class);
manager = (UserManager) userManagerConstructor.newInstance(props);
}
catch (Exception e) {
logger.error("Could not instantiate UserManager "+ userManagerClass.getName());
throw new RuntimeException(e);
}
}
else {
manager = new XmlUserManager(props);
}
return manager;
}
private ProjectManager loadProjectManager(Props props) {
logger.info("Loading JDBC for project management");
JdbcProjectLoader loader = new JdbcProjectLoader(props);
ProjectManager manager = new ProjectManager(loader, props);
return manager;
}
private ExecutorManager loadExecutorManager(Props props) throws Exception {
JdbcExecutorLoader loader = new JdbcExecutorLoader(props);
ExecutorManager execManager = new ExecutorManager(props, loader);
return execManager;
}
private ScheduleManager loadScheduleManager(ExecutorManager execManager, SLAManager slaManager, Props props ) throws Exception {
ScheduleManager schedManager = new ScheduleManager(execManager, projectManager, slaManager, new JdbcScheduleLoader(props));
return schedManager;
}
private SLAManager loadSLAManager(Props props) throws SLAManagerException {
SLAManager slaManager = new SLAManager(executorManager, new JdbcSLALoader(props), props);
return slaManager;
}
/**
* Returns the web session cache.
*
* @return
*/
public SessionCache getSessionCache() {
return sessionCache;
}
/**
* Returns the velocity engine for pages to use.
*
* @return
*/
public VelocityEngine getVelocityEngine() {
return velocityEngine;
}
/**
*
* @return
*/
public UserManager getUserManager() {
return userManager;
}
/**
*
* @return
*/
public ProjectManager getProjectManager() {
return projectManager;
}
/**
*
*/
public ExecutorManager getExecutorManager() {
return executorManager;
}
public SLAManager getSLAManager() {
return slaManager;
}
public ScheduleManager getScheduleManager() {
return scheduleManager;
}
/**
* Creates and configures the velocity engine.
*
* @param devMode
* @return
*/
private VelocityEngine configureVelocityEngine(final boolean devMode) {
VelocityEngine engine = new VelocityEngine();
engine.setProperty("resource.loader", "classpath, jar");
engine.setProperty("classpath.resource.loader.class", ClasspathResourceLoader.class.getName());
engine.setProperty("classpath.resource.loader.cache", !devMode);
engine.setProperty("classpath.resource.loader.modificationCheckInterval", 5L);
engine.setProperty("jar.resource.loader.class", JarResourceLoader.class.getName());
engine.setProperty("jar.resource.loader.cache", !devMode);
engine.setProperty("resource.manager.logwhenfound", false);
engine.setProperty("input.encoding", "UTF-8");
engine.setProperty("output.encoding", "UTF-8");
engine.setProperty("directive.set.null.allowed", true);
engine.setProperty("resource.manager.logwhenfound", false);
engine.setProperty("velocimacro.permissions.allow.inline", true);
engine.setProperty("velocimacro.library.autoreload", devMode);
engine.setProperty("velocimacro.library", "/azkaban/webapp/servlet/velocity/macros.vm");
engine.setProperty("velocimacro.permissions.allow.inline.to.replace.global", true);
engine.setProperty("velocimacro.arguments.strict", true);
engine.setProperty("runtime.log.invalid.references", devMode);
engine.setProperty("runtime.log.logsystem.class", Log4JLogChute.class);
engine.setProperty("runtime.log.logsystem.log4j.logger", Logger.getLogger("org.apache.velocity.Logger"));
engine.setProperty("parser.pool.size", 3);
return engine;
}
private ClassLoader getBaseClassloader() throws MalformedURLException {
final ClassLoader retVal;
String hadoopHome = System.getenv("HADOOP_HOME");
String hadoopConfDir = System.getenv("HADOOP_CONF_DIR");
if (hadoopConfDir != null) {
logger.info("Using hadoop config found in " + hadoopConfDir);
retVal = new URLClassLoader(new URL[] { new File(hadoopConfDir)
.toURI().toURL() }, getClass().getClassLoader());
} else if (hadoopHome != null) {
logger.info("Using hadoop config found in " + hadoopHome);
retVal = new URLClassLoader(
new URL[] { new File(hadoopHome, "conf").toURI().toURL() },
getClass().getClassLoader());
} else {
logger.info("HADOOP_HOME not set, using default hadoop config.");
retVal = getClass().getClassLoader();
}
return retVal;
}
public ClassLoader getClassLoader() {
return baseClassLoader;
}
/**
* Returns the global azkaban properties
*
* @return
*/
public Props getServerProps() {
return props;
}
/**
* Azkaban using Jetty
*
* @param args
*/
public static void main(String[] args) throws Exception {
logger.error("Starting Jetty Azkaban Executor...");
Props azkabanSettings = AzkabanServer.loadProps(args);
if (azkabanSettings == null) {
logger.error("Azkaban Properties not loaded.");
logger.error("Exiting Azkaban...");
return;
}
int maxThreads = azkabanSettings.getInt("jetty.maxThreads", DEFAULT_THREAD_NUMBER);
boolean ssl;
int port;
final Server server = new Server();
if (azkabanSettings.getBoolean("jetty.use.ssl", true)) {
int sslPortNumber = azkabanSettings.getInt("jetty.ssl.port", DEFAULT_SSL_PORT_NUMBER);
port = sslPortNumber;
ssl = true;
logger.info("Setting up Jetty Https Server with port:" + sslPortNumber + " and numThreads:" + maxThreads);
SslSocketConnector secureConnector = new SslSocketConnector();
secureConnector.setPort(sslPortNumber);
secureConnector.setKeystore(azkabanSettings.getString("jetty.keystore"));
secureConnector.setPassword(azkabanSettings.getString("jetty.password"));
secureConnector.setKeyPassword(azkabanSettings.getString("jetty.keypassword"));
secureConnector.setTruststore(azkabanSettings.getString("jetty.truststore"));
secureConnector.setTrustPassword(azkabanSettings.getString("jetty.trustpassword"));
secureConnector.setHeaderBufferSize(MAX_HEADER_BUFFER_SIZE);
server.addConnector(secureConnector);
}
else {
ssl = false;
port = azkabanSettings.getInt("jetty.port", DEFAULT_PORT_NUMBER);
SocketConnector connector = new SocketConnector();
connector.setPort(port);
connector.setHeaderBufferSize(MAX_HEADER_BUFFER_SIZE);
server.addConnector(connector);
}
String hostname = azkabanSettings.getString("jetty.hostname", "localhost");
azkabanSettings.put("server.hostname", hostname);
azkabanSettings.put("server.port", port);
azkabanSettings.put("server.useSSL", String.valueOf(ssl));
app = new AzkabanWebServer(server, azkabanSettings);
boolean checkDB = azkabanSettings.getBoolean(AzkabanDatabaseSetup.DATABASE_CHECK_VERSION, false);
if (checkDB) {
AzkabanDatabaseSetup setup = new AzkabanDatabaseSetup(azkabanSettings);
setup.loadTableInfo();
if(setup.needsUpdating()) {
logger.error("Database is out of date.");
setup.printUpgradePlan();
logger.error("Exiting with error.");
System.exit(-1);
}
}
QueuedThreadPool httpThreadPool = new QueuedThreadPool(maxThreads);
server.setThreadPool(httpThreadPool);
String staticDir = azkabanSettings.getString("web.resource.dir", DEFAULT_STATIC_DIR);
logger.info("Setting up web resource dir " + staticDir);
Context root = new Context(server, "/", Context.SESSIONS);
root.setMaxFormContentSize(MAX_FORM_CONTENT_SIZE);
root.setResourceBase(staticDir);
ServletHolder index = new ServletHolder(new IndexServlet());
root.addServlet(index, "/index");
root.addServlet(index, "/");
ServletHolder staticServlet = new ServletHolder(new DefaultServlet());
root.addServlet(staticServlet, "/css/*");
root.addServlet(staticServlet, "/js/*");
root.addServlet(staticServlet, "/images/*");
root.addServlet(staticServlet, "/favicon.ico");
root.addServlet(new ServletHolder(new ProjectManagerServlet()),"/manager");
root.addServlet(new ServletHolder(new ExecutorServlet()),"/executor");
root.addServlet(new ServletHolder(new HistoryServlet()), "/history");
root.addServlet(new ServletHolder(new ScheduleServlet()),"/schedule");
root.addServlet(new ServletHolder(new JMXHttpServlet()),"/jmx");
String viewerPluginDir = azkabanSettings.getString("viewer.plugin.dir", "plugins/viewer");
app.setViewerPlugins(loadViewerPlugins(root, viewerPluginDir, app.getVelocityEngine()));
root.setAttribute(AzkabanServletContextListener.AZKABAN_SERVLET_CONTEXT_KEY, app);
try {
server.start();
}
catch (Exception e) {
logger.warn(e);
Utils.croak(e.getMessage(), 1);
}
Runtime.getRuntime().addShutdownHook(new Thread() {
public void run() {
logger.info("Shutting down http server...");
try {
app.close();
server.stop();
server.destroy();
}
catch (Exception e) {
logger.error("Error while shutting down http server.", e);
}
logger.info("kk thx bye.");
}
});
logger.info("Server running on " + (ssl ? "ssl" : "") + " port " + port + ".");
}
private static List<ViewerPlugin> loadViewerPlugins(Context root, String pluginPath, VelocityEngine ve) {
File viewerPluginPath = new File(pluginPath);
if (!viewerPluginPath.exists()) {
return Collections.<ViewerPlugin>emptyList();
}
ArrayList<ViewerPlugin> installedViewerPlugins = new ArrayList<ViewerPlugin>();
ClassLoader parentLoader = AzkabanWebServer.class.getClassLoader();
File[] pluginDirs = viewerPluginPath.listFiles();
ArrayList<String> jarPaths = new ArrayList<String>();
for (File pluginDir: pluginDirs) {
if (!pluginDir.exists()) {
logger.error("Error viewer plugin path " + pluginDir.getPath() + " doesn't exist.");
continue;
}
if (!pluginDir.isDirectory()) {
logger.error("The plugin path " + pluginDir + " is not a directory.");
continue;
}
// Load the conf directory
File propertiesDir = new File(pluginDir, "conf");
Props pluginProps = null;
if (propertiesDir.exists() && propertiesDir.isDirectory()) {
File propertiesFile = new File(propertiesDir, "plugin.properties");
File propertiesOverrideFile = new File(propertiesDir, "override.properties");
if (propertiesFile.exists()) {
if (propertiesOverrideFile.exists()) {
pluginProps = PropsUtils.loadProps(null, propertiesFile, propertiesOverrideFile);
}
else {
pluginProps = PropsUtils.loadProps(null, propertiesFile);
}
}
else {
logger.error("Plugin conf file " + propertiesFile + " not found.");
continue;
}
}
else {
logger.error("Plugin conf path " + propertiesDir + " not found.");
continue;
}
String pluginName = pluginProps.getString("viewer.name");
String pluginWebPath = pluginProps.getString("viewer.path");
int pluginOrder = pluginProps.getInt("viewer.order", 0);
boolean pluginHidden = pluginProps.getBoolean("viewer.hidden", false);
List<String> extLibClasspath = pluginProps.getStringList("viewer.external.classpaths", (List<String>)null);
String pluginClass = pluginProps.getString("viewer.servlet.class");
if (pluginClass == null) {
logger.error("Viewer class is not set.");
}
else {
logger.error("Plugin class " + pluginClass);
}
URLClassLoader urlClassLoader = null;
File libDir = new File(pluginDir, "lib");
if (libDir.exists() && libDir.isDirectory()) {
File[] files = libDir.listFiles();
ArrayList<URL> urls = new ArrayList<URL>();
for (int i=0; i < files.length; ++i) {
try {
URL url = files[i].toURI().toURL();
urls.add(url);
} catch (MalformedURLException e) {
logger.error(e);
}
}
if (extLibClasspath != null) {
for (String extLib : extLibClasspath) {
try {
File file = new File(pluginDir, extLib);
URL url = file.toURI().toURL();
urls.add(url);
} catch (MalformedURLException e) {
logger.error(e);
}
}
}
urlClassLoader = new URLClassLoader(urls.toArray(new URL[urls.size()]), parentLoader);
}
else {
logger.error("Library path " + propertiesDir + " not found.");
continue;
}
Class<?> viewerClass = null;
try {
viewerClass = urlClassLoader.loadClass(pluginClass);
}
catch (ClassNotFoundException e) {
logger.error("Class " + pluginClass + " not found.");
continue;
}
String source = FileIOUtils.getSourcePathFromClass(viewerClass);
logger.info("Source jar " + source);
jarPaths.add("jar:file:" + source);
Constructor<?> constructor = null;
try {
constructor = viewerClass.getConstructor(Props.class);
} catch (NoSuchMethodException e) {
logger.error("Constructor not found in " + pluginClass);
continue;
}
Object obj = null;
try {
obj = constructor.newInstance(pluginProps);
} catch (Exception e) {
logger.error(e);
}
if (!(obj instanceof AbstractAzkabanServlet)) {
logger.error("The object is not an AbstractViewerServlet");
continue;
}
AbstractAzkabanServlet avServlet = (AbstractAzkabanServlet)obj;
root.addServlet(new ServletHolder(avServlet), "/" + pluginWebPath + "/*");
installedViewerPlugins.add(new ViewerPlugin(pluginName, pluginWebPath, pluginOrder, pluginHidden));
}
// Velocity needs the jar resource paths to be set.
String jarResourcePath = StringUtils.join(jarPaths, ", ");
logger.info("Setting jar resource path " + jarResourcePath);
ve.addProperty("jar.resource.loader.path", jarResourcePath);
// Sort plugins based on order
Collections.sort(installedViewerPlugins, new Comparator<ViewerPlugin>() {
@Override
public int compare(ViewerPlugin o1, ViewerPlugin o2) {
return o1.getOrder() - o2.getOrder();
}
});
return installedViewerPlugins;
}
public List<ViewerPlugin> getViewerPlugins() {
return viewerPlugins;
}
/**
* Loads the Azkaban property file from the AZKABAN_HOME conf directory
*
* @return
*/
private static Props loadConfigurationFromAzkabanHome() {
String azkabanHome = System.getenv("AZKABAN_HOME");
if (azkabanHome == null) {
logger.error("AZKABAN_HOME not set. Will try default.");
return null;
}
if (!new File(azkabanHome).isDirectory() || !new File(azkabanHome).canRead()) {
logger.error(azkabanHome + " is not a readable directory.");
return null;
}
File confPath = new File(azkabanHome, DEFAULT_CONF_PATH);
if (!confPath.exists() || !confPath.isDirectory()
|| !confPath.canRead()) {
logger.error(azkabanHome + " does not contain a readable conf directory.");
return null;
}
return loadAzkabanConfigurationFromDirectory(confPath);
}
/**
* Returns the set temp dir
*
* @return
*/
public File getTempDirectory() {
return tempDir;
}
private static Props loadAzkabanConfigurationFromDirectory(File dir) {
File azkabanPrivatePropsFile = new File(dir, AZKABAN_PRIVATE_PROPERTIES_FILE);
File azkabanPropsFile = new File(dir, AZKABAN_PROPERTIES_FILE);
Props props = null;
try {
// This is purely optional
if (azkabanPrivatePropsFile.exists() && azkabanPrivatePropsFile.isFile()) {
logger.info("Loading azkaban private properties file" );
props = new Props(null, azkabanPrivatePropsFile);
}
if (azkabanPropsFile.exists() && azkabanPropsFile.isFile()) {
logger.info("Loading azkaban properties file" );
props = new Props(props, azkabanPropsFile);
}
} catch (FileNotFoundException e) {
logger.error("File not found. Could not load azkaban config file", e);
} catch (IOException e) {
logger.error("File found, but error reading. Could not load azkaban config file", e);
}
return props;
}
private void configureMBeanServer() {
logger.info("Registering MBeans...");
mbeanServer = ManagementFactory.getPlatformMBeanServer();
registerMbean("jetty", new JmxJettyServer(server));
registerMbean("scheduler", new JmxScheduler(scheduleManager));
registerMbean("slaManager", new JmxSLAManager(slaManager));
registerMbean("executorManager", new JmxExecutorManager(executorManager));
}
public void close() {
try {
for (ObjectName name : registeredMBeans) {
mbeanServer.unregisterMBean(name);
logger.info("Jmx MBean " + name.getCanonicalName() + " unregistered.");
}
} catch (Exception e) {
logger.error("Failed to cleanup MBeanServer", e);
}
scheduleManager.shutdown();
slaManager.shutdown();
executorManager.shutdown();
}
private void registerMbean(String name, Object mbean) {
Class<?> mbeanClass = mbean.getClass();
ObjectName mbeanName;
try {
mbeanName = new ObjectName(mbeanClass.getName() + ":name=" + name);
mbeanServer.registerMBean(mbean, mbeanName);
logger.info("Bean " + mbeanClass.getCanonicalName() + " registered.");
registeredMBeans.add(mbeanName);
} catch (Exception e) {
logger.error("Error registering mbean " + mbeanClass.getCanonicalName(), e);
}
}
public List<ObjectName> getMbeanNames() {
return registeredMBeans;
}
public MBeanInfo getMBeanInfo(ObjectName name) {
try {
return mbeanServer.getMBeanInfo(name);
} catch (Exception e) {
logger.error(e);
return null;
}
}
public Object getMBeanAttribute(ObjectName name, String attribute) {
try {
return mbeanServer.getAttribute(name, attribute);
} catch (Exception e) {
logger.error(e);
return null;
}
}
}