title: Service jboss.web.deployment.default-host./.realm is already registered
body: <p>I'm trying to deploy three different ear files to the same Jboss server... </p>
  
  <p>One of them doesn't have a context root, and the other two have it, but it's different. I mean, let's take the three ears as one.ear, two.ear and three.ear:</p>
  
  <p>one.ear has:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;jboss-web&gt;
      &lt;context-root&gt;/&lt;/context-root&gt;
  &lt;/jboss-web&gt;
  </code></pre>
  
  <p>two.ear has:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;jboss-web&gt;
      &lt;context-root&gt;/two&lt;/context-root&gt;
  &lt;/jboss-web&gt;
  </code></pre>
  
  <p>three.ear has none.</p>
  
  <p>When I try to star Jboss (7 AS), I got this:</p>
  
  <pre><code>16:01:31,962 ERROR [org.jboss.msc.service.fail] (MSC service thread 1-5) MSC00001: Failed to start service jboss.deployment.subunit."one-ear.ear"."one.war".INSTALL: org.jboss.msc.service.StartException in service jboss.deployment.subunit."one-ear.ear"."one.war".INSTALL: Failed to process phase INSTALL of subdeployment "one.war" of deployment "one-ear.ear"
      at org.jboss.as.server.deployment.DeploymentUnitPhaseService.start(DeploymentUnitPhaseService.java:119) [jboss-as-server-7.1.1.Final.jar:7.1.1.Final]
      at org.jboss.msc.service.ServiceControllerImpl$StartTask.startService(ServiceControllerImpl.java:1811) [jboss-msc-1.0.2.GA.jar:1.0.2.GA]
      at org.jboss.msc.service.ServiceControllerImpl$StartTask.run(ServiceControllerImpl.java:1746) [jboss-msc-1.0.2.GA.jar:1.0.2.GA]
      at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source) [rt.jar:1.6.0_45]
      at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) [rt.jar:1.6.0_45]
      at java.lang.Thread.run(Unknown Source) [rt.jar:1.6.0_45]
  Caused by: org.jboss.as.server.deployment.DeploymentUnitProcessingException: JBAS018027: Failed to add JBoss Web deployment service
      at org.jboss.as.web.deployment.WarDeploymentProcessor.processDeployment(WarDeploymentProcessor.java:320)
      at org.jboss.as.web.deployment.WarDeploymentProcessor.deploy(WarDeploymentProcessor.java:114)
      at org.jboss.as.server.deployment.DeploymentUnitPhaseService.start(DeploymentUnitPhaseService.java:113) [jboss-as-server-7.1.1.Final.jar:7.1.1.Final]
      ... 5 more
  Caused by: org.jboss.msc.service.DuplicateServiceException: Service jboss.web.deployment.default-host./.realm is already registered
      at org.jboss.msc.service.ServiceRegistrationImpl.setInstance(ServiceRegistrationImpl.java:154) [jboss-msc-1.0.2.GA.jar:1.0.2.GA]
      at org.jboss.msc.service.ServiceControllerImpl.startInstallation(ServiceControllerImpl.java:227) [jboss-msc-1.0.2.GA.jar:1.0.2.GA]
      at org.jboss.msc.service.ServiceContainerImpl.install(ServiceContainerImpl.java:560) [jboss-msc-1.0.2.GA.jar:1.0.2.GA]
      at org.jboss.msc.service.ServiceTargetImpl.install(ServiceTargetImpl.java:201) [jboss-msc-1.0.2.GA.jar:1.0.2.GA]
      at org.jboss.msc.service.ServiceControllerImpl$ChildServiceTarget.install(ServiceControllerImpl.java:2228) [jboss-msc-1.0.2.GA.jar:1.0.2.GA]
      at org.jboss.msc.service.ServiceTargetImpl.install(ServiceTargetImpl.java:201) [jboss-msc-1.0.2.GA.jar:1.0.2.GA]
      at org.jboss.msc.service.ServiceControllerImpl$ChildServiceTarget.install(ServiceControllerImpl.java:2228) [jboss-msc-1.0.2.GA.jar:1.0.2.GA]
      at org.jboss.msc.service.ServiceBuilderImpl.install(ServiceBuilderImpl.java:307) [jboss-msc-1.0.2.GA.jar:1.0.2.GA]
      at org.jboss.as.web.deployment.WarDeploymentProcessor.processDeployment(WarDeploymentProcessor.java:269)
      ... 7 more
  </code></pre>
  
  <p>I have read that this error could be thrown when two apps in the same server have the same context root, but this is not the case... what is happening?</p>