我可以在我的独立群集中部署我的耳朵和战争。我的2场战争是针对HA单身人士的。启动第一个独立的jboss-eap-6后不久，我开始第二个。当我的所有应用程序都已成功部署后，我打开J-Console，我注意到我的一个单独战争正在第一个jboss-eap-6上运行而第二个单独战争正在第二个jboss-eap-6上运行。同样在Jconsole中，只有1个jboss-eap-6报告为主要报告。
我的问题是：在jboss-eap-6 standalone.xml中是否有某种方法我只能强制使用1个jboss-eap-6来运行单例HA战争。或者我是否必须将战争打包到耳中？
答案 0 :(得分：0)
我认为standalone.xml中没有任何内容可以改变战争的行为。在任何情况下，您都应该将standalone-ha.xml用于已部署HA单例的群集。
JBoss高可用性Singleton架构在JBoss EAP 5和6之间发生了显着变化。
在JBoss EAP 5下，您只需将可部署对象放在deploy-hasingleton特殊部署文件夹中。在JBoss EAP 6下，您的类需要实现JBoss服务层，特别是org.jboss.msc.service.Service和org.jboss.msc.service.ServiceActivator。正是这些服务类的实现控制着HA Singleton的实例化和管理。我没有尝试将hasingleton部署为战争，我有一些疑问，因为我怀疑依赖服务类可能在Web容器中不可用。
ServiceActivator负责管理Service的生命周期。 ServiceActivator实现类需要在文件META-INF/service/org.jboss.msc.service.ServiceActivator中列出，以便JBoss在启动/部署期间激活它。
实施例： 创建服务激活器
public abstract class SingletonActivator<T extends Serializable> implements ServiceActivator {
@Override
public SingletonService<String> instantiateSingleton() {
return new SingletonService<String>();
}
public ServiceName getServiceName() {
return ServiceName.JBOSS.append("my", "ha", "singleton");
}
/**
* Activated by the Service Activator
*
* @param service
* @param serviceName
* - the Singleton Service Name that is registered in the JBOSS cluster
*/
@Override
public final void activate(ServiceActivatorContext context) {
SingletonService<T> service = instantiateSingleton();
SingletonService<T> singleton = new SingletonService<T>(service, getServiceName());
/*
* The NamePreference is a combination of the node name (-Djboss.node.name) and the name of
* the configured cache "singleton". If there is more than 1 node, it is possible to add more than
* one name and the election will use the first available node in that list.
*/
// e.g. singleton.setElectionPolicy(new PreferredSingletonElectionPolicy(new SimpleSingletonElectionPolicy(), new NamePreference("node1/singleton")));
// or singleton.setElectionPolicy(new PreferredSingletonElectionPolicy(new SimpleSingletonElectionPolicy(), new NamePreference("node1/singleton"), new
// NamePreference("node2/singleton")));
singleton.build(new DelegatingServiceContainer(context.getServiceTarget(), context.getServiceRegistry())).setInitialMode(ServiceController.Mode.ACTIVE).install();
}
}
创建HA单例服务类，该类单独负责查找和调用包含业务逻辑的EJB
public class SingletonService<T> implements Service<T> {
protected ScheduledExecutorService deployDelayThread = null;
/**
* The node we are running on
*/
protected String nodeName;
/**
* A flag whether the service is started (or scheduled to be started)
*/
protected final AtomicBoolean started = new AtomicBoolean(false);
/**
* Container life cycle call upon activation. This will construct the singleton instance in this JVM and start the Timer.
*/
@Override
public final void start(StartContext context) throws StartException {
this.nodeName = System.getProperty("jboss.node.name");
logger.info("Starting service '" + this.getClass().getName() + "' on node " + nodeName);
if (!started.compareAndSet(false, true)) {
throw new StartException("The service " + this.getClass().getName() + " is still started!");
}
// MSC does not allow this thread to be blocked so we let the service know that the start is asynchronous and the result will be advised later.
// We delay the actual deployment of the Singleton for a few seconds to allow time for a HASingleton Election to be held and won by one of the instances.
// If the winner is not this instance (prior to deployemnt) then stop(Context) is invoked which sets started to false and the deployment does not occur.
// context.asynchronous();
deployDelayThread.schedule(new StartSingletonAsync(context), 10, TimeUnit.SECONDS);
context.complete();
}
/** Introduces a 5s delay in starting the Singleton bean giving time for the the ha singleton election to be held and won */
private class StartSingletonAsync implements Runnable {
private StartSingletonAsync(StartContext context) {
}
@Override
public void run() {
try {
startSingletonBean();
} catch (StartException e) {
logger.info("Start Exception", e);
}
// be nice to the garbage collector, we don't need this any more
deployDelayThread.shutdown();
deployDelayThread = null;
}
}
private void startSingletonBean() throws StartException {
try {
if (!started.get()) {
throw new StartException("Aborted due to service stopping");
}
// Start your EJB
InitialContext ic = new InitialContext();
bean = ic.lookup(getJndiName());
bean.startHaSingleton();
logger.info("*** Master Only: HASingleton service " + getJndiName() + " started on master:" + nodeName);
if (!bean.isRunning()) {
logger.error("ERROR Bean should be running");
}
} catch (NamingException e) {
throwStartException(e);
}
}
private void throwStartException(Exception e) throws StartException {
String message = "Could not initialize HASingleton" + getJndiName() + " on " + nodeName;
logger.error(message, e);
throw new StartException(message, e);
}
/**
* Container life cycle call when activated
*/
@Override
public final void stop(StopContext context) {
if (deployDelayThread != null) {
deployDelayThread.shutdownNow();
}
if (!started.compareAndSet(true, false) || bean == null) {
logger.warn("The service '" + this.getClass().getName() + "' is not active!");
} else {
try {
InitialContext ic = new InitialContext();
bean = (JmxMBean) ic.lookup(getJndiName());
bean.stopHaSingleton();
logger.info("*** Master Only: HASingleton service " + getJndiName() + " stopped on master:" + nodeName);
} catch (EJBException e) {
// Note: all these exceptions are already logged by JBoss
} catch (NamingException e) {
logger.error("Could not stop HASingleton service " + getJndiName() + " on " + nodeName, e);
}
logger.info("MASTER ONLY HASingleton service '" + this.getClass().getName() + "' Stopped on node " + nodeName);
}
}
private String getJndiName() {
return "java.global/path/to/your/singleton/ejb";
}
}
最后在META-INF/servcie/org.jboss.msc.service.ServiceActivator
com.mycompany.singletons.SingletonActivator
您可能还需要在jar中的manifest META-INF/MANIFEST.MF文件中添加依赖项，如下所示：Dependencies: org.jboss.msc, org.jboss.as.clustering.singleton, org.jboss.as.server
Redhat在https://access.redhat.com/documentation/en-US/JBoss_Enterprise_Application_Platform/6.4/html/Development_Guide/Implement_an_HA_Singleton.html提供了更广泛的实施指南。您可能需要创建一个Redhat帐户才能访问它。 JBoss发行版中还有一个快速入门的例子。
答案 1 :(得分：0)
因此，在进一步评估之后，2个单身人士最终会在几分钟后合并在一起，从而创造出1个单身人士。