[wildfly-dev] Migration management operation - open questions

[Miroslav Novak]

Hi,

we have a few questions related to correct behavior of the :migrate operation for following subsystems:
- JBoss Web to Undertow [1]
- HornetQ to Apache ActiveMQ Artemis [2]
- jacorb to iiop-openjdk [3]

Part of it was already clarified on wildfly-dev list [4] but there are still unspecified topics related to work flow and expected results of migration operation. We summarized them into following questions:

1. What will be the precise set of steps the administrator must perform to migrate legacy subsystem in standalone mode and domain mode? What are the specifics and limitations for domain mode?

2. If legacy subsystem is dependent on element defined in another subsystem but does not exist in new configuration, can migration operation create it on its own? Or should it just print warning?
-- For example legacy subsystem can depend on socket-binding which does not exist in new configuration. Should migration operation create socket-binding?

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?

4. What should happen if some other subsystem is expecting definition of element in new migrated configuration but it's not there after migration?
-- For example ejb subsystem has by default "activemq-ra" as default resource adapter for MDBs and migrated Artemis subsystem will not contain it.

5. We generally believe that if the :migrate operation can detect an error, it should do that and provide a warning. Only when an error situation can be detected at runtime  the :migrate operation should be allowed not to print any warning. Is this accounted for, or at least do we agree on this?

6. Should the extensions for old subsystems be left in configuration after migration?

7. Should the :migrate operation return reload-required header?

Thank you,
Mirek

[1] https://issues.jboss.org/browse/EAP7-326
[2] https://issues.jboss.org/browse/EAP7-327
[3] https://issues.jboss.org/browse/EAP7-328
[4] http://lists.jboss.org/pipermail/wildfly-dev/2015-April/003841.html