[javaee-spec users] [jsr342-experts] Re: Re: Re: Modularization Framework/SPI

From: Werner Keil <>
Date: Thu, 26 Jul 2012 14:10:12 +0200

Thanks, for the info.

How representative is that, how many people really answered it?

Btw, the "Application Framework" category you mixed up things worse than
e.g. Matt Raible in recent years.
Comparing Spring or Seam with Hibernate, that's totally messing up UI,
Middleware and things like ORM in one pot, not very reliable[?]

On Thu, Jul 26, 2012 at 1:57 PM, Jevgeni Kabanov <
> wrote:

> This all is very anecdotal. In our survey most folks did not indicate that
> they use OSGi or anything like it:
> (only a third are our customers, the rest just the folks across the
> community that responded)
> There were also a bunch of open questions and although the no downtime
> provisioning of application is a great concern, there were fairly little
> issues with multiple library version. And modularity without a good
> isolation model is not a way to solve hot update or the class loading
> issues you mentioned.
> I'm afraid we're trying to solve the issues of the largest shops, which
> are always more complex than the rest and probably do need a custom
> solution built on OSGi or whatnot. And they already have access to OSGi on
> the Glassfish, Websphere and so on.
> Wouldn't it make more sense to accommodate OSGi as an optional extension
> of the spec and just define better interoperation? I'm afraid that baking
> modularity into the Java EE spec will introduce more complexity than it's
> worth for most of the Java EE ecosystem.
> JK
> --
> Founder & CEO of ZeroTurnaround
> @ekabanov | Skype: ekabanov |
> On Thursday, 26 July 2012 at 14:41, Jeff Genender wrote:
> Hi Craig... thanks for the response and I darned well agree with a lot in
> this email ;-)
> answers in line...
> On Jul 25, 2012, at 7:30 PM, Craig Ringer wrote:
> On 07/25/2012 09:53 PM, Jeff Genender wrote:
> In my world, I am seeing users pushing modularity in front of JavaEE and
> we are really missing this boat. A large section of my clients are moving
> to OSGi stacks picking and choosing what they want in their stacks, with
> some building their own JavaEE light containers (JTA, JPA).
> Can you explain in a bit more detail what problems they're encountering
> that leave them forced to take this option? Application and business
> problems, not just the common "we need X because we've always used it"
> issues I see come up sometimes.
> Here are what I usually hear:
> 1) The comments made come along the line of the thick stack and having
> resources used by major components that aren't used. Complaint is EE-bloat.
> 2) Ability to hot deploy/undeploy without corrupting the classloaders.
> Example... try to deploy/deploy a war many times in a standard JavaEE
> container until an OutOf Memory exception occurs.
> 3) Ability to provision applications and services on the fly without
> having to reboot - think cloud-like Applications As A Service (AaaS).
> 4) Ability to prevent class clashing with multiple versions. Wanting to
> run multiple applications in the same container without worry for parent
> classloading corruption - the class tree classloading issues.
> 5) Dependent execution. The ability to run transitive dependencies on
> other applications/jars, much like a Unix inti.d or Windows services model.
> i.e. an application can;t run until its other dependent applications are
> running.
> OSGi seems to wor in this model, albeit with a great amount of pain.
> Do you have people who really must swap out the JTA implementation in a an
> app server with a different one in order to meet business or application
> requirements? JPA I fully understand, but JTA? I'm surprised and interested
> by that.
> Yes, many of my clients are interested in the Blueprint JTA implementation
> or use a local resource like Spring. Hence those who want to use Spring
> local transactions can rip out the JTA, or if they need XA, they wire up
> Aries/Blueprint and enable aries-transaction. I see this choice a lot.
> I'm having very frustrating problems with the lack of plugability of some
> of the upper layer stuff myself. Hibernate is a very poor fit for the needs
> of an app I'm working on, but getting EclipseLink to integrate well into
> AS7 is a major pain. I appreciate the need for pluggability at least at the
> higher levels of the stack, and it's been a major source of pain for me
> since I started working with Java EE.
> My comments were specific to CDI and some low level, tightly integrated
> components in the server like the EJB3 implementation, JTA, JCA, etc. These
> are tightly integrated and - from what I've seen in AS7's sources and on
> the bug tracker - the existing SPIs appear inadeaute to allow them to
> simply be swapped out and replaced. I'd *love* to be wrong about this, but
> my experience even trying to swap out theoretically pluggable things like
> JPA implementations argues against it.
> I would like to see a certain baseline of infrastructure locked in place
> as something thatthe app server does not have to support replacing (it
> still may if it chooses). In exchange, certain higher level components like
> JSF2, JPA2, maybe JAX-RS, etc would *have* to support being swapped out
> with either app-bundled implementations or modules installed in the app
> server. This would give vendors realistic test targets and narrow the
> number of configurations to something (almost) testable. It would also make
> it clearer which specs need really complete SPIs as a priority.
> As for needing a module system: I could not possibly agree more, and think
> that things like CDI *should* be modules within the app server - for app
> server maintainability and good design. Sure enough you'll see that all the
> low level components in AS7 are modules. I just don't think the spec should
> require the server vendor to support applications swapping out arbitrary
> modules; that needs to be confined to modules implementing specs where
> there's a good enough SPI.
> The trouble with the module system issue is that JBoss modules is probably
> a bit too basic, and OSGi is (IMO) convoluted and horrible to work with.
> There isn't a really good candidate.
> I completely agree with you... but I am just concerned we are going to
> miss the boat if we keep putting this off. ;-)
> Jeff
> --
> Craig Ringer

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