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

From: Reza Rahman <>
Date: Thu, 26 Jul 2012 11:39:27 -0400

Please note my earlier email about "nice to have" vs. an actual
compelling need. The particular issue you mention does happen somewhat
infrequently (and hence I see as an edge case) and are generally
solvable in the vast majority of cases using things app server
class-loading tweaks (when it is even needed beyond simply using Maven
and being careful about what's placed in the application server's

On 7/26/2012 11:30 AM, Jason T. Greene wrote:
> Really? You have never seen users complain about EE classloader
> isolation problems? It's pretty common these days for EE deployments
> to suck in 10+ libraries that conflict with another deployments 10+
> libraries.
> On 7/26/12 10:27 AM, Reza Rahman wrote:
>> Thanks for the clarification, but I don't think that I've misinterpreted
>> much. The overwhelming indication the way I've seen it first hand is
>> that people don't really need general modularity that much and have much
>> more bread-and-butter concerns.
>> On 7/26/2012 11:15 AM, Jason T. Greene wrote:
>>> I think Jeff is frustrated because we are missing his underlying
>>> point. What I think hes saying (and I am sure he will correct me), is
>>> that we need standardized modularity badly. Some are sick of the
>>> packaging and portability challenges in Java EE, and are considering
>>> other options.
>>> To his point we should be careful not to equate perceptions of low
>>> OSGi use with users not wanting modularity.
>>> On 7/26/12 9:28 AM, Reza Rahman wrote:
>>>> I can understand that this is something you feel strongly about, but
>>>> kindly get a hold of yourself (and I know you can do better :-)). I do
>>>> talk with everyone that I can about these issues as frequently as I
>>>> can
>>>> simply because I care (and have absolutely no personal stake in any of
>>>> this). The reality that I see consistently matches up very closely
>>>> with
>>>> what Jevgeni is saying rather than what you are saying, sorry.
>>>> On 7/26/2012 10:19 AM, Jeff Genender wrote:
>>>>> Guys,
>>>>> I don't get the support for the marketing drivel. We all come from
>>>>> different backgrounds. Be it Jboss modules, OSGI, roll your own, or
>>>>> whatever. If you want data, go look at the Jboss modules, Geronimo
>>>>> (Websphere CE), Glassfish, Equinox, Karaf, Felix user mailing lists
>>>>> and the number of blogs on the subject. Go do your own count of
>>>>> users... That's *not* marketing... Thats *not* anecdotal... That's
>>>>> our
>>>>> users. That is who we represent. That's *real* data. guess what...
>>>>> They *use* our designs. Let's please stop the BS at this point. This
>>>>> is a dead horse. If you have something useful to contribute, please
>>>>> do it...but let's stop the +1s on the loaded marketing material.
>>>>> Jeff
>>>>> Sent from my iPhone
>>>>> On Jul 26, 2012, at 9:04 AM, Reza Rahman <
>>>>> <>> wrote:
>>>>>> +1 (and I can guarantee that I'm a dispassionate observer on this
>>>>>> one
>>>>>> :-)).
>>>>>> On 7/26/2012 8:23 AM, Jevgeni Kabanov wrote:
>>>>>>> I'm glad we agree on the sentiment.
>>>>>>> The paper is NOT based on customer data. This was a community-wide
>>>>>>> poll with 1450+ answers. It agrees with other larger polls, e.g.
>>>>>>> one
>>>>>>> conducted by Eclipse. It certainly is not my side of the fence,
>>>>>>> it's
>>>>>>> what the world looks like, at least in the outline.
>>>>>>> My point was that OSGi adoption is fairly low, and it's the
>>>>>>> poster-boy of Java modularity story. Is there an actual need
>>>>>>> outside
>>>>>>> the largest shops? Can we accommodate the largest shops in the spec
>>>>>>> without impacting the majority of the community? These are
>>>>>>> important
>>>>>>> questions that need answering before we commit to any one solution.
>>>>>>> JK
>>>>>>> --
>>>>>>> Founder & CEO of ZeroTurnaround
>>>>>>> @ekabanov | Skype: ekabanov |
>>>>>>> On Thursday, 26 July 2012 at 15:17, Jeff Genender wrote:
>>>>>>>> Jevgeni,
>>>>>>>> I have to disagree vehemently with your fist comment. Your
>>>>>>>> presentation of your paper is strawman. Your paper/analysis is
>>>>>>>> from
>>>>>>>> your customers which is your side of the fence. You have a small
>>>>>>>> slice of a different sort of customer and your survey is directed
>>>>>>>> at people who use JRebel and its likes which is anti OSGi in
>>>>>>>> nature. Different strokes for different folks but I am certainly
>>>>>>>> not calling yours anecdotal... just strawman. ;-)
>>>>>>>> I wasn't stating OSGi is the end-all. But it does fit a need for
>>>>>>>> what people want form what *I* see. People want the same thing
>>>>>>>> with LiveRebel. The areas I listed is what LiveRebel helps to
>>>>>>>> define as well.
>>>>>>>> Hence, what you produce is exactly what I want and what your last
>>>>>>>> statement pretty much summed up. We need something that allows
>>>>>>>> someone to plug in whatever modular system for now, be it OSGi,
>>>>>>>> JBoss Modules, or even LiveRebel. You stated exactly what I want
>>>>>>>> to see.
>>>>>>>> Jeff
>>>>>>>> On Jul 26, 2012, at 6:57 AM, 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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