Hi Reza, welcome back! Linda is busy with JPA today so let me try to
answer your questions...
Reza Rahman wrote on 05/26/11 02:36 PM:
> Linda,
>
> Overall, this is a good start. At the same time though let me state up-front two
> concerns:
>
> Firstly, I hope all of this is implemented in away that does not effect
> developers of simple applications that do not require cloud support and never
> will.
Yes, that's our goal.
> Secondly, I hope the cloud support does not take up so much bandwidth for
> the Java EE 7 JSRs that more mundane but equally/more important things get put
> in the back-burner.
Right now I'm more concerned about the reverse. We have a pretty good handle
on what's required for all those more "mundane" things, whereas "cloud support"
is still pretty amorphous. There's a tendency to work on the problems we
understand instead of the hard problems we don't yet understand. Clearly it's
the latter where we're looking for the most help from the expert group.
> Specific comments on the document:
> * I was left wondering about the specifics of how a tenant ID get's established
> in the first place. While it might not be possible to spec that out completely,
> it might be a good idea to have some guidelines so that vendors don't diverge
> far beyond effective future collaboration.
Right now my feeling is that there's a number of different ways this could
be done, and it won't matter to the application which one is chosen, so there's
no need to overly constrain the solution. If you have a specific scenario
that you're worried about, let us know.
> * I think it is best not to make cloud support the default platform behavior but
> rather something that is enabled specifically. If this really becomes cumbersome
> in the future because a majority of applications are on the cloud, we can always
> make it the default later. Going the other way round if cloud computing turns
> out to be just another over-hyped, vendor-driven bust with limited practical
> applicability is going to be difficult I think.
Our current thinking is that an application is going to have to explicitly
say "I'm designed for the cloud environment". When we understand everything
that that implies, we might change our mind.
> * I prefer readable Java identifiers to abstruse UUIDs :-).
We want a tenant ID to be usable as a database primary key, a file name, etc.,
so I think we only need to constrain the ID sufficiently to make it usable
in this way.
> * I definitely think cloud support should be optional or at least not added to
> the Web Profile.
Yes, we expect most of the cloud support to be optional for the entire
platform. A Java EE 6 product that provides no cloud support should be
able to be updated to support all the other things in Java EE 7 without
also having to explicitly support the cloud environment. It may need to
understand things about the cloud environment so that it can safely ignore
them, or provide nop or trivial implementations of them, but it shouldn't
be required to actually run in a cloud environment.
> * It's difficult to make a call on ignoring the cloud settings without looking
> at the overall cloud solution in detail. For now, I would say implementations
> that do not support the cloud should simply ignore the cloud settings. This
> would also make development on local machines that need not support the cloud
> easier while the application can maybe later deployed to a cloud enabled server
> for testing, production, etc.
Right, we need to get further into the details before we can decide this.
> * Multi-tenancy comes in a very wide array of facets -- the same application
> deployed to different machines with tenant-specific configuration talking to a
> tenant-specific database, Multiple tenants using the same application but going
> to tenant-specific databases, multiple tenants using the same shared database,
> and so on. It would be important to get those details hashed out centrally and
> propagate it to the different JSRs as opposed to different JSRs coming up with
> their own solutions. In this case, if we don't do that chaos might ensue :-).
Yes, that's the kind of thing we'll need to discuss further.