Slave host error handling in a managed domain should not assume the context failure description node can be converted to ModelType.OBJECT

This failure was reported following a failed op:

Host Controller] 12:11:33,014 ERROR [org.jboss.as.controller.management-operation] (HttpManagementService-threads - 1) JBAS014612: Operation ("composite") failed - address: ([]): java.lang.IllegalArgumentException
[Host Controller] at org.jboss.dmr.ModelValue.getChild(ModelValue.java:108) [jboss-dmr-1.1.1.Final-redhat-1.jar:1.1.1.Final-redhat-1]
[Host Controller] at org.jboss.dmr.ModelNode.get(ModelNode.java:798) [jboss-dmr-1.1.1.Final-redhat-1.jar:1.1.1.Final-redhat-1]
[Host Controller] at org.jboss.as.domain.controller.operations.coordination.DomainFinalResultHandler.collectHostFailures(DomainFinalResultHandler.java:158) [jboss-as-host-controller-7.1.0.Final-redhat-1.jar:7.1.0.Final-redhat-1]
[Host Controller] at org.jboss.as.domain.controller.operations.coordination.DomainFinalResultHandler.execute(DomainFinalResultHandler.java:80) [jboss-as-host-controller-7.1.0.Final-redhat-1.jar:7.1.0.Final-redhat-1]
[Host Controller] at org.jboss.as.controller.AbstractOperationContext.executeStep(AbstractOperationContext.java:387) [jboss-as-controller-7.1.0.Final-redhat-1.jar:7.1.0.Final-redhat-1]
[Host Controller] at org.jboss.as.controller.AbstractOperationContext.doCompleteStep(AbstractOperationContext.java:274) [jboss-as-controller-7.1.0.Final-redhat-1.jar:7.1.0.Final-redhat-1]
[Host Controller] at org.jboss.as.controller.AbstractOperationContext.completeStep(AbstractOperationContext.java:202) [jboss-as-controller-7.1.0.Final-redhat-1.jar:7.1.0.Final-redhat-1]
[Host Controller] at org.jboss.as.domain.controller.operations.coordination.OperationCoordinatorStepHandler.executeTwoPhaseOperation(OperationCoordinatorStepHandler.java:225) [jboss-as-host-controller-7.1.0.Final-redhat-1.jar:7.1.0.Final-redhat-1]
[Host Controller] at org.jboss.as.domain.controller.operations.coordination.OperationCoordinatorStepHandler.execute(OperationCoordinatorStepHandler.java:118) [jboss-as-host-controller-7.1.0.Final-redhat-1.jar:7.1.0.Final-redhat-1]
[Host Controller] at org.jboss.as.domain.controller.operations.coordination.PrepareStepHandler.execute(PrepareStepHandler.java:85) [jboss-as-host-controller-7.1.0.Final-redhat-1.jar:7.1.0.Final-redhat-1]
[Host Controller] at org.jboss.as.controller.AbstractOperationContext.executeStep(AbstractOperationContext.java:387) [jboss-as-controller-7.1.0.Final-redhat-1.jar:7.1.0.Final-redhat-1]
[Host Controller] at org.jboss.as.controller.AbstractOperationContext.doCompleteStep(AbstractOperationContext.java:274) [jboss-as-controller-7.1.0.Final-redhat-1.jar:7.1.0.Final-redhat-1]
[Host Controller] at org.jboss.as.controller.AbstractOperationContext.completeStep(AbstractOperationContext.java:202) [jboss-as-controller-7.1.0.Final-redhat-1.jar:7.1.0.Final-redhat-1]
[Host Controller] at org.jboss.as.controller.ModelControllerImpl.execute(ModelControllerImpl.java:121) [jboss-as-controller-7.1.0.Final-redhat-1.jar:7.1.0.Final-redhat-1]
[Host Controller] at org.jboss.as.controller.ModelControllerImpl$1.execute(ModelControllerImpl.java:309) [jboss-as-controller-7.1.0.Final-redhat-1.jar:7.1.0.Final-redhat-1]
[Host Controller] at org.jboss.as.controller.ModelControllerImpl$1.execute(ModelControllerImpl.java:299) [jboss-as-controller-7.1.0.Final-redhat-1.jar:7.1.0.Final-redhat-1]
[Host Controller] at org.jboss.as.domain.http.server.DomainApiHandler.processRequest(DomainApiHandler.java:294) [jboss-as-domain-http-interface-7.1.0.Final-redhat-1.jar:7.1.0.Final-redhat-1]
[Host Controller] at org.jboss.as.domain.http.server.DomainApiHandler.doHandle(DomainApiHandler.java:201) [jboss-as-domain-http-interface-7.1.0.Final-redhat-1.jar:7.1.0.Final-redhat-1]
[Host Controller] at org.jboss.as.domain.http.server.DomainApiHandler.handle(DomainApiHandler.java:208) [jboss-as-domain-http-interface-7.1.0.Final-redhat-1.jar:7.1.0.Final-redhat-1]
[Host Controller] at org.jboss.as.domain.http.server.security.SubjectAssociationHandler.handle(SubjectAssociationHandler.java:51) [jboss-as-domain-http-interface-7.1.0.Final-redhat-1.jar:7.1.0.Final-redhat-1]
[Host Controller] at org.jboss.com.sun.net.httpserver.Filter$Chain.doFilter(Filter.java:78)
[Host Controller] at org.jboss.sun.net.httpserver.AuthFilter.doFilter(AuthFilter.java:69)
[Host Controller] at org.jboss.com.sun.net.httpserver.Filter$Chain.doFilter(Filter.java:81)
[Host Controller] at org.jboss.sun.net.httpserver.ServerImpl$Exchange$LinkHandler.handle(ServerImpl.java:710)
[Host Controller] at org.jboss.com.sun.net.httpserver.Filter$Chain.doFilter(Filter.java:78)
[Host Controller] at org.jboss.as.domain.http.server.RealmReadinessFilter.doFilter(RealmReadinessFilter.java:54) [jboss-as-domain-http-interface-7.1.0.Final-redhat-1.jar:7.1.0.Final-redhat-1]
[Host Controller] at org.jboss.com.sun.net.httpserver.Filter$Chain.doFilter(Filter.java:81)
[Host Controller] at org.jboss.sun.net.httpserver.ServerImpl$Exchange.run(ServerImpl.java:682)
[Host Controller] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110) [rt.jar:1.7.0]
[Host Controller] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603) [rt.jar:1.7.0]
[Host Controller] at java.lang.Thread.run(Thread.java:722) [rt.jar:1.7.0]
[Host Controller] at org.jboss.threads.JBossThread.run(JBossThread.java:122) [jboss-threads-2.0.0.GA-redhat-1.jar:2.0.0.GA-redhat-1]

The relevant logic at DomainFinalResultHandler.collectHostFailures(DomainFinalResultHandler.java:158) does this:

context.getFailureDescription().get(HOST_FAILURE_DESCRIPTIONS).set(hostFailureResults);

The IAE indicates the ModelNode returned by context.getFailureDescription() has already been initialized to some other ModelType (probably ModelType.STRING) and thus can't be used to store a failure description with a ModelType.OBJECT structure.

We need to figure out why the failure description was already initialized in order to decide how best to deal with this.