Cannot add new Cloud Access 2.0 Server to existing Cloud Access 1.5 cluster

NetIQ Cloud Access (NCA) 1.5 up and running without problems in it's own cluster. With the NCA 2.0 release, administrator wanted to add new NCA 2.0 server to existing cluster, and eventually upgrade all nodes as per the docs. After the option to join existing cluster was enabled, and the install started, a message appeared indicating that the NCA 2.0 server could not join the cluster.

The catalina log files on the server showed the following:

Dec 6, 2013 2:21:53 PM com.sun.jersey.server.impl.application.WebApplicationImpl onException
SEVERE: Internal server error
javax.ws.rs.WebApplicationException
    at com.novell.adroit.server.service.ApplianceResource.addToCluster(ApplianceResource.java:926)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at com.sun.jersey.server.impl.model.method.dispatch.AbstractResourceMethodDispatchProvider$TypeOutInvoker._dispatch(AbstractResourceMethodDispatchProvider.java:156)
    at com.sun.jersey.server.impl.model.method.dispatch.ResourceJavaMethodDispatcher.dispatch(ResourceJavaMethodDispatcher.java:67)
    at com.sun.jersey.server.impl.uri.rules.HttpMethodRule.accept(HttpMethodRule.java:163)
    at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:111)
    at com.sun.jersey.server.impl.uri.rules.ResourceClassRule.accept(ResourceClassRule.java:71)
    at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:111)
    at com.sun.jersey.server.impl.uri.rules.RootResourceClassesRule.accept(RootResourceClassesRule.java:63)
    at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:654)
    at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:612)
    at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:603)

Customer had installed Mobile and not Cloud Access 2.0. Avoid joining a "MobileAccess 2.0" server to a Cloud Access 1.5 cluster, which is not supported.

If you eventually want 'mobile' for you cluster setup, you need to add the CloudAccess 2.0 to the Cloud Access 1.5 cluster and upgrade all nodes to 2.0, then you could either

- add the Mobile connector (basically turning cloud into mobile), or

- add another "MobileAccess" node to the NCA 2.0 cluster, promote it, and remove the NCA nodes (to have a pure 'Mobile' 2.0 cluster).