> 3. What is the expected behavior when part which was configured as part of the legacy subsystem is now configured outside of new subsystem having just reference to it? Should the migration operation create the additional configuration even when it is manipulating with configuration parts outside of the subsystem?
> -- For example ssl configuration of https connector/listener. In Web subsystem it is part of the connector configuration, in Undertow it is just reference to security realm and it is defined as part of the security realms, should new security realm be created with equivalent configuration to the one in legacy Web subsystem?
>

I'll let Stuart respond to this. Looking at the WebMigrateOperation (the
handler for the web subsystem migrate op) it looks to be adding a
security realm.

Yes, at the moment I do create new security realms, and also add the IO subsystem with a default config if it is not already present. The names for the security realm will be jbossweb-migration-security-realm(n), where n is the lowest number that does not result in a name collision.

Stuart