Linda,
in JPA multi-tenancy is really important. It simplifies the implementation of
many usecases currently only possible to implement with application specific extensions...
In broader scope JMX extensions, standardized (REST based?) deployment and management APIs would be nice as well...
This would be even beneficial in more traditional projects..
--adam
On 06.06.2011, at 23:47, Linda DeMichiel wrote:
> Antonio,
>
> Thanks for the input.
>
> As Bill noted in his earlier email, it was our expectation that most
> cloud support will be optional for the entire platform.
>
> We have mulled over the issue of a Cloud profile ourselves, although
> we are not yet convinced it is needed for the Java EE 7 release.
> However, this is definitely a discussion that we will need to have in
> the group once we have worked out what enabling the Java EE Platform
> for the cloud entails.
>
> Our current thinking is that we expect that the burden on existing
> implementations to ignore cloud support they do not want will be
> small. If implementations do want to include cloud support, we are
> expecting the burden/changes to not be so large as to justify the
> introduction of a Cloud profile in Java EE 7. We will of course
> reevaluate as we go further into our work.
>
> With regard to the database issues you raise, I think this depends on
> the database and what the application needs to store in it. Databases
> vary widely in terms of footprint (even when empty), so creating
> separate databases may not always be a scalable solution. In the
> database area, at least, I think we're going to need to look at
> accommodating a range of solutions (at least eventually), which is
> also something that the JPA expert group will need to consider.
>
> regards,
>
> -Linda
>
>
>
>
> On 6/2/2011 10:47 AM, Antonio Goncalves wrote:
>> I'm following reza's comments on "not everybody needs cloud" and I think we should have a Cloud profile instead of
>> having it on the EE platform ? Profiles can be subsets of EE as well as super sets. So why not having a Cloud profile
>> that includes most of EE and adds extra cloud features ? This way we could also leave EE as it is (which means no Cloud,
>> Cluster, multi-tenant...). What do you think ?
>>
>> Correct me if I'm wrong, but latelly I've been earing a lot about multi-tenant. It looks to me that the world is moving
>> the other way now. Application servers, databases... tend to be lighter and lighter in terms of resources. So why bother
>> having multi-tenancy ? Just instanciate several servers or DBs and each instance only hosts one application. If I'm not
>> wrong (Nicolas Leroux can correct me) a Play! instance takes less than 100Kb or RAM. With profiles, OSGi and modularity
>> arriving, the platform is shrinking and the app servers will shrink too, so why not goaling for several app servers with
>> one application instead of one app server with several applications (same for DBs) ? That's why I think all these PAAS
>> concepts could go into a profile, not EE. Multi-tenancy is useful for some people, but not everybody.
>>
>> My 2 cents
>>
>> Antonio
>>
>>
>>
>> On Sat, May 28, 2011 at 1:02 AM, Reza Rahman <reza_rahman_at_lycos.com <mailto:reza_rahman_at_lycos.com>> wrote:
>>
>> Bill,
>>
>> OK, all of what you said makes perfect sense - thanks for the prompt response.
>>
>> We'll put some more thoughts on some of this internally and will try to share helpful details.
>>
>> Cheers,
>> Reza
>>
>>
>>
>> On 5/27/2011 6:20 PM, Bill Shannon wrote:
>>
>> 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.
>>
>>
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>>
>>
>>
>>
>> --
>> Antonio Goncalves
>> Software architect and Java Champion
>>
>> Web site <http://www.antoniogoncalves.org> | Twitter <http://twitter.com/agoncal> | Blog
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>> <http://www.parisjug.org>
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