Re: [INFO] Apache Karaf 5 will be internally based on OSGi R8

[Grzegorz Grzybek]

Quoting one statement of yours:

So for long running apps graal cost is wayy more than the runtime gain
> and I guess it is where Karaf 5 will sit, long running aggregated and
> unified apps (by providing a single admin interface for all kind of apps
> and not a different one for spring/spring-boot, microprofile, ee, osgi
> etc).
>

I agree. I still believe in "Java applications servers" (whatever the set
of standards - real or de-facto - is used). And I still believe in
long-running apps.

regards
Grzegorz Grzybek

czw., 25 mar 2021 o 10:33 Romain Manni-Bucau 
napisał(a):

> Le jeu. 25 mars 2021 à 09:35, Grzegorz Grzybek  a
> écrit :
>
> > Thanks Romain for the details! (see inline)
> >
> > czw., 25 mar 2021 o 08:31 Romain Manni-Bucau 
> > napisał(a):
> >
> > > Le jeu. 25 mars 2021 à 07:13, Grzegorz Grzybek 
> a
> > > écrit :
> > >
> > > > Good morning!
> > > >
> > > > śr., 24 mar 2021 o 19:57 Romain Manni-Bucau 
> > > > napisał(a):
> > > >
> > > > > in terms of arch yes, the key feature is to have a tree classloader
> > and
> > > > not
> > > > > a graph (drops all the build complexity of OSGi and enable scanning
> > > > > pluggability, yeah).
> > > > >
> > > >
> > > > Graph → Tree sounds like OSGi → JavaEE...
> > > > This can prevent user feature to install a bundle that overrides
> system
> > > > services I know that (without "134 Subsystem Service
> Specification"
> > > and
> > > > without hooks) effectively OSGi runtime is "flat" - every bundle wire
> > is
> > > > equal and resolution rules apply. Also every OSGi service is equal
> and
> > > > service rank is taken into account.
> > > >
> > >
> > > Yes and no, a service registration can still use @Priority or a SPI
> > method
> > > to be sorted, only thing it can prevent is to put conflicting deps in
> the
> > > same bootstrap classloader (that said these days OSGi is rarely used
> for
> > > that and since by design the bootstrap loader will be a single app - ie
> > > without any conflict at build time - it is actually sane).
> > >
> >
> > In JavaEE, a WAR can (mostly) configure some providers, so e.g.,
> > DocumentBuilderFactory may return WAR-specific instance. But it's not
> > possible to affect this service loading in other WARs.
> > In OSGi, a bundle can register some service that'll become the valid
> > service for remaining bundles.
> > So I understand that Karaf 5 keeps the OSGi philosophy here, right?
> >
>
> Yes and not, the small language trick is do you speak of bootstrap services
> or profile or app in Karaf 5.
> Bootstrap services can do whatever they want (ie same as OSGi in terms of
> impact even if technicaly it is not linked) but all other layers
> (profile+app) must stay static and almost immutable.
>
>
> >
> >
> > >
> > >
> > > >
> > > > I'm trying to imagine how "it’s powered by OSGi R8 (but you will see
> > that
> > > > it’s more an internal point)" works - is the "Level1: Karaf itself" a
> > > > graph-based layer of bundle classloaders, while applications are
> given
> > > > their own single classloader (kind of like WebSphere is (was?) based
> on
> > > > OSGi and WARs/EARs hand single classloader or like Wildfly/EAP that's
> > > > internally a graph of JBoss Modules, while WARs/EARs have single
> > > > classloader)?
> > > >
> > > > java.util.ServiceLoader is dynamic in nature and is a final (IMO) and
> > > quite
> > > > elegant discovery solution in tree-(ClassLoader)-based monoliths
> where
> > > you
> > > > "deploy" applications. And it's reflection based.
> > > >
> > >
> > > Last point does not have to be true, see some graalvm integrations for
> > > example, it is reflection less depends how you handle the build phase
> but
> > > being reflection "full" by default enables to keep the tooling
> (testing)
> > > working without breaking your IDE.
> > >
> >
> > Mind that I'm not very experienced with Graal/Quarkus, so my questions
> may
> > be invalid ;)
> >
>
> I was expecting it to come at some point - and btw we can note the fun
> thing that the big change is GraalVM but everybody speaks of Quarkus which
> is just a rebranding of already existing things, no technology jump by
> itself ;).
> My vision is that karaf 5 fulfills the microservices pitfalls and drawback
> by bringing back a well know and secure deployment alternative to all that.
> Indeed graal-ifying your app will make it save some memory, maybe some CPU
> cycle in some cases but if you optimize your java code you can get the same
> in terms of CPU cycles (and even faster in some cases).
> In terms of bootstrap you can same a few ms due to the classloading but not
> much more and CDS already solves part of it (at the cost of memory).
> So for long running apps graal cost is wayy more than the runtime gain
> and I guess it is where Karaf 5 will sit, long running aggregated and
> unified apps (by providing a single admin interface for all kind of apps
> and not a different one for spring/spring-boot, microprofile, ee, osgi
> etc).
>
> Hope it makes 

Re: [INFO] Apache Karaf 5 will be internally based on OSGi R8

[Jean-Baptiste Onofre]

Just to be concrete about Karaf wording:

- Library: class loader at Karaf system level
- Service: loaded at Karaf system level
- Profile: class loader (not attended at karaf system level)
- Module: one class loader eventually with profile parent class loader and 
karaf system classloader

I hope it helps ;)

Regards
JB

> Le 25 mars 2021 à 10:33, Romain Manni-Bucau  a écrit :
> 
> Le jeu. 25 mars 2021 à 09:35, Grzegorz Grzybek  > a
> écrit :
> 
>> Thanks Romain for the details! (see inline)
>> 
>> czw., 25 mar 2021 o 08:31 Romain Manni-Bucau 
>> napisał(a):
>> 
>>> Le jeu. 25 mars 2021 à 07:13, Grzegorz Grzybek  a
>>> écrit :
>>> 
 Good morning!
 
 śr., 24 mar 2021 o 19:57 Romain Manni-Bucau 
 napisał(a):
 
> in terms of arch yes, the key feature is to have a tree classloader
>> and
 not
> a graph (drops all the build complexity of OSGi and enable scanning
> pluggability, yeah).
> 
 
 Graph → Tree sounds like OSGi → JavaEE...
 This can prevent user feature to install a bundle that overrides system
 services I know that (without "134 Subsystem Service Specification"
>>> and
 without hooks) effectively OSGi runtime is "flat" - every bundle wire
>> is
 equal and resolution rules apply. Also every OSGi service is equal and
 service rank is taken into account.
 
>>> 
>>> Yes and no, a service registration can still use @Priority or a SPI
>> method
>>> to be sorted, only thing it can prevent is to put conflicting deps in the
>>> same bootstrap classloader (that said these days OSGi is rarely used for
>>> that and since by design the bootstrap loader will be a single app - ie
>>> without any conflict at build time - it is actually sane).
>>> 
>> 
>> In JavaEE, a WAR can (mostly) configure some providers, so e.g.,
>> DocumentBuilderFactory may return WAR-specific instance. But it's not
>> possible to affect this service loading in other WARs.
>> In OSGi, a bundle can register some service that'll become the valid
>> service for remaining bundles.
>> So I understand that Karaf 5 keeps the OSGi philosophy here, right?
>> 
> 
> Yes and not, the small language trick is do you speak of bootstrap services
> or profile or app in Karaf 5.
> Bootstrap services can do whatever they want (ie same as OSGi in terms of
> impact even if technicaly it is not linked) but all other layers
> (profile+app) must stay static and almost immutable.
> 
> 
>> 
>> 
>>> 
>>> 
 
 I'm trying to imagine how "it’s powered by OSGi R8 (but you will see
>> that
 it’s more an internal point)" works - is the "Level1: Karaf itself" a
 graph-based layer of bundle classloaders, while applications are given
 their own single classloader (kind of like WebSphere is (was?) based on
 OSGi and WARs/EARs hand single classloader or like Wildfly/EAP that's
 internally a graph of JBoss Modules, while WARs/EARs have single
 classloader)?
 
 java.util.ServiceLoader is dynamic in nature and is a final (IMO) and
>>> quite
 elegant discovery solution in tree-(ClassLoader)-based monoliths where
>>> you
 "deploy" applications. And it's reflection based.
 
>>> 
>>> Last point does not have to be true, see some graalvm integrations for
>>> example, it is reflection less depends how you handle the build phase but
>>> being reflection "full" by default enables to keep the tooling (testing)
>>> working without breaking your IDE.
>>> 
>> 
>> Mind that I'm not very experienced with Graal/Quarkus, so my questions may
>> be invalid ;)
>> 
> 
> I was expecting it to come at some point - and btw we can note the fun
> thing that the big change is GraalVM but everybody speaks of Quarkus which
> is just a rebranding of already existing things, no technology jump by
> itself ;).
> My vision is that karaf 5 fulfills the microservices pitfalls and drawback
> by bringing back a well know and secure deployment alternative to all that.
> Indeed graal-ifying your app will make it save some memory, maybe some CPU
> cycle in some cases but if you optimize your java code you can get the same
> in terms of CPU cycles (and even faster in some cases).
> In terms of bootstrap you can same a few ms due to the classloading but not
> much more and CDS already solves part of it (at the cost of memory).
> So for long running apps graal cost is wayy more than the runtime gain
> and I guess it is where Karaf 5 will sit, long running aggregated and
> unified apps (by providing a single admin interface for all kind of apps
> and not a different one for spring/spring-boot, microprofile, ee, osgi etc).
> 
> Hope it makes sense and I'm not too far from what JB had in mind but this
> is where I see a looot of value for such a design.
> 
> 
>> 
>> 
>>> 
>>> 
 How about graal/quarkus?
 Let me be clear here - quarkus/graal/native approach is cool and makes
>>> Java
 great again™, but I know that "enteprise" still likes the idea of
 

Re: [INFO] Apache Karaf 5 will be internally based on OSGi R8

[Romain Manni-Bucau]

Le jeu. 25 mars 2021 à 09:35, Grzegorz Grzybek  a
écrit :

> Thanks Romain for the details! (see inline)
>
> czw., 25 mar 2021 o 08:31 Romain Manni-Bucau 
> napisał(a):
>
> > Le jeu. 25 mars 2021 à 07:13, Grzegorz Grzybek  a
> > écrit :
> >
> > > Good morning!
> > >
> > > śr., 24 mar 2021 o 19:57 Romain Manni-Bucau 
> > > napisał(a):
> > >
> > > > in terms of arch yes, the key feature is to have a tree classloader
> and
> > > not
> > > > a graph (drops all the build complexity of OSGi and enable scanning
> > > > pluggability, yeah).
> > > >
> > >
> > > Graph → Tree sounds like OSGi → JavaEE...
> > > This can prevent user feature to install a bundle that overrides system
> > > services I know that (without "134 Subsystem Service Specification"
> > and
> > > without hooks) effectively OSGi runtime is "flat" - every bundle wire
> is
> > > equal and resolution rules apply. Also every OSGi service is equal and
> > > service rank is taken into account.
> > >
> >
> > Yes and no, a service registration can still use @Priority or a SPI
> method
> > to be sorted, only thing it can prevent is to put conflicting deps in the
> > same bootstrap classloader (that said these days OSGi is rarely used for
> > that and since by design the bootstrap loader will be a single app - ie
> > without any conflict at build time - it is actually sane).
> >
>
> In JavaEE, a WAR can (mostly) configure some providers, so e.g.,
> DocumentBuilderFactory may return WAR-specific instance. But it's not
> possible to affect this service loading in other WARs.
> In OSGi, a bundle can register some service that'll become the valid
> service for remaining bundles.
> So I understand that Karaf 5 keeps the OSGi philosophy here, right?
>

Yes and not, the small language trick is do you speak of bootstrap services
or profile or app in Karaf 5.
Bootstrap services can do whatever they want (ie same as OSGi in terms of
impact even if technicaly it is not linked) but all other layers
(profile+app) must stay static and almost immutable.


>
>
> >
> >
> > >
> > > I'm trying to imagine how "it’s powered by OSGi R8 (but you will see
> that
> > > it’s more an internal point)" works - is the "Level1: Karaf itself" a
> > > graph-based layer of bundle classloaders, while applications are given
> > > their own single classloader (kind of like WebSphere is (was?) based on
> > > OSGi and WARs/EARs hand single classloader or like Wildfly/EAP that's
> > > internally a graph of JBoss Modules, while WARs/EARs have single
> > > classloader)?
> > >
> > > java.util.ServiceLoader is dynamic in nature and is a final (IMO) and
> > quite
> > > elegant discovery solution in tree-(ClassLoader)-based monoliths where
> > you
> > > "deploy" applications. And it's reflection based.
> > >
> >
> > Last point does not have to be true, see some graalvm integrations for
> > example, it is reflection less depends how you handle the build phase but
> > being reflection "full" by default enables to keep the tooling (testing)
> > working without breaking your IDE.
> >
>
> Mind that I'm not very experienced with Graal/Quarkus, so my questions may
> be invalid ;)
>

I was expecting it to come at some point - and btw we can note the fun
thing that the big change is GraalVM but everybody speaks of Quarkus which
is just a rebranding of already existing things, no technology jump by
itself ;).
My vision is that karaf 5 fulfills the microservices pitfalls and drawback
by bringing back a well know and secure deployment alternative to all that.
Indeed graal-ifying your app will make it save some memory, maybe some CPU
cycle in some cases but if you optimize your java code you can get the same
in terms of CPU cycles (and even faster in some cases).
In terms of bootstrap you can same a few ms due to the classloading but not
much more and CDS already solves part of it (at the cost of memory).
So for long running apps graal cost is wayy more than the runtime gain
and I guess it is where Karaf 5 will sit, long running aggregated and
unified apps (by providing a single admin interface for all kind of apps
and not a different one for spring/spring-boot, microprofile, ee, osgi etc).

Hope it makes sense and I'm not too far from what JB had in mind but this
is where I see a looot of value for such a design.


>
>
> >
> >
> > > How about graal/quarkus?
> > > Let me be clear here - quarkus/graal/native approach is cool and makes
> > Java
> > > great again™, but I know that "enteprise" still likes the idea of
> > > "application servers", so I hope Karaf5 is NOT going to be
> > > "Kubernetes/OpenShift first" - long running processes with reflection
> and
> > > dynamic classloading are still relevant.
> > >
> >
> > Can you precise it there? Quarkus has two modes: JVM (where it is
> > equivalent to most microprofile servers without the standard/spec
> support)
> > and native mode (where arthur does the same closer to graalvm).
> > First mode does not need much but last one does not concern karaf 5 AFAIK
> 

Re: [INFO] Apache Karaf 5 will be internally based on OSGi R8

[Grzegorz Grzybek]

Thanks Romain for the details! (see inline)

czw., 25 mar 2021 o 08:31 Romain Manni-Bucau 
napisał(a):

> Le jeu. 25 mars 2021 à 07:13, Grzegorz Grzybek  a
> écrit :
>
> > Good morning!
> >
> > śr., 24 mar 2021 o 19:57 Romain Manni-Bucau 
> > napisał(a):
> >
> > > in terms of arch yes, the key feature is to have a tree classloader and
> > not
> > > a graph (drops all the build complexity of OSGi and enable scanning
> > > pluggability, yeah).
> > >
> >
> > Graph → Tree sounds like OSGi → JavaEE...
> > This can prevent user feature to install a bundle that overrides system
> > services I know that (without "134 Subsystem Service Specification"
> and
> > without hooks) effectively OSGi runtime is "flat" - every bundle wire is
> > equal and resolution rules apply. Also every OSGi service is equal and
> > service rank is taken into account.
> >
>
> Yes and no, a service registration can still use @Priority or a SPI method
> to be sorted, only thing it can prevent is to put conflicting deps in the
> same bootstrap classloader (that said these days OSGi is rarely used for
> that and since by design the bootstrap loader will be a single app - ie
> without any conflict at build time - it is actually sane).
>

In JavaEE, a WAR can (mostly) configure some providers, so e.g.,
DocumentBuilderFactory may return WAR-specific instance. But it's not
possible to affect this service loading in other WARs.
In OSGi, a bundle can register some service that'll become the valid
service for remaining bundles.
So I understand that Karaf 5 keeps the OSGi philosophy here, right?


>
>
> >
> > I'm trying to imagine how "it’s powered by OSGi R8 (but you will see that
> > it’s more an internal point)" works - is the "Level1: Karaf itself" a
> > graph-based layer of bundle classloaders, while applications are given
> > their own single classloader (kind of like WebSphere is (was?) based on
> > OSGi and WARs/EARs hand single classloader or like Wildfly/EAP that's
> > internally a graph of JBoss Modules, while WARs/EARs have single
> > classloader)?
> >
> > java.util.ServiceLoader is dynamic in nature and is a final (IMO) and
> quite
> > elegant discovery solution in tree-(ClassLoader)-based monoliths where
> you
> > "deploy" applications. And it's reflection based.
> >
>
> Last point does not have to be true, see some graalvm integrations for
> example, it is reflection less depends how you handle the build phase but
> being reflection "full" by default enables to keep the tooling (testing)
> working without breaking your IDE.
>

Mind that I'm not very experienced with Graal/Quarkus, so my questions may
be invalid ;)


>
>
> > How about graal/quarkus?
> > Let me be clear here - quarkus/graal/native approach is cool and makes
> Java
> > great again™, but I know that "enteprise" still likes the idea of
> > "application servers", so I hope Karaf5 is NOT going to be
> > "Kubernetes/OpenShift first" - long running processes with reflection and
> > dynamic classloading are still relevant.
> >
>
> Can you precise it there? Quarkus has two modes: JVM (where it is
> equivalent to most microprofile servers without the standard/spec support)
> and native mode (where arthur does the same closer to graalvm).
> First mode does not need much but last one does not concern karaf 5 AFAIK
> since spring-boot has its own graal integration, microprofile servers too
> (potentially EE ones too even if I didnt see one yet) and OSGi has its own
> through winegroewer so overall Karaf 5 sounds like the aggregator platform
> which would fallback on dropping it to be graal compliant (since you'll
> drop classloaders which makes all the power of the solution.
>

I imagine that Quarkus/Graal is designed mostly to develop apps that can
quickly start/stop and "application servers" is not the most desired goal
here.
And I was thinking about the native mode, where everything is mostly set up
at build time.



>
>
> >
> >
> > > In terms of service since the launcher is a monolith it has the key
> > > advantage to be able to scan all then dispatch so I guess we can just
> > have
> > > a ServiceLoader kind of SPI for "module service" impls and order them
> as
> > > needed. a ModuleService { setModuleServiceRegistry(Registry); } would
> > then
> > > do the trick probably, no need of fancy IoC for such low level
> framework
> > > IMHO.
> > >
> >
> > So clear distinguishing between "applications" and "server plugins" (with
> > e.g., replaceable Jackson as JSON provider) - am I interpreting your
> > statements correctly Romain?
> >
>
> For example yes even if I suspect the services should stick to very
> technical layers and isolated from the profile+app loaders so means jackson
> from the bootstrap loader shouldnt be usable in an app but you could
> configure it to leak (in the profile - ie the parent classes to use).
> Very generally services shouldnt leak but profiles will so a provider would
> sit in a profile loader IMHO.
> Services would be more about logging 

Re: [INFO] Apache Karaf 5 will be internally based on OSGi R8

[Grzegorz Grzybek]

Good morning!

śr., 24 mar 2021 o 19:57 Romain Manni-Bucau 
napisał(a):

> in terms of arch yes, the key feature is to have a tree classloader and not
> a graph (drops all the build complexity of OSGi and enable scanning
> pluggability, yeah).
>

Graph → Tree sounds like OSGi → JavaEE...
This can prevent user feature to install a bundle that overrides system
services I know that (without "134 Subsystem Service Specification" and
without hooks) effectively OSGi runtime is "flat" - every bundle wire is
equal and resolution rules apply. Also every OSGi service is equal and
service rank is taken into account.

I'm trying to imagine how "it’s powered by OSGi R8 (but you will see that
it’s more an internal point)" works - is the "Level1: Karaf itself" a
graph-based layer of bundle classloaders, while applications are given
their own single classloader (kind of like WebSphere is (was?) based on
OSGi and WARs/EARs hand single classloader or like Wildfly/EAP that's
internally a graph of JBoss Modules, while WARs/EARs have single
classloader)?

java.util.ServiceLoader is dynamic in nature and is a final (IMO) and quite
elegant discovery solution in tree-(ClassLoader)-based monoliths where you
"deploy" applications. And it's reflection based.
How about graal/quarkus?
Let me be clear here - quarkus/graal/native approach is cool and makes Java
great again™, but I know that "enteprise" still likes the idea of
"application servers", so I hope Karaf5 is NOT going to be
"Kubernetes/OpenShift first" - long running processes with reflection and
dynamic classloading are still relevant.


> In terms of service since the launcher is a monolith it has the key
> advantage to be able to scan all then dispatch so I guess we can just have
> a ServiceLoader kind of SPI for "module service" impls and order them as
> needed. a ModuleService { setModuleServiceRegistry(Registry); } would then
> do the trick probably, no need of fancy IoC for such low level framework
> IMHO.
>

So clear distinguishing between "applications" and "server plugins" (with
e.g., replaceable Jackson as JSON provider) - am I interpreting your
statements correctly Romain?

regards
Grzegorz Grzybek


>
> Romain Manni-Bucau
> @rmannibucau  |  Blog
>  | Old Blog
>  | Github <
> https://github.com/rmannibucau> |
> LinkedIn  | Book
> <
> https://www.packtpub.com/application-development/java-ee-8-high-performance
> >
>
>
> Le mer. 24 mars 2021 à 19:13, Jean-Baptiste Onofre  a
> écrit :
>
> > Hi Romain,
> >
> > About OSGi, the way I did it (up to now), it’s as you describe:
> >
> > - Karaf "launcher"
> > — Libraries service
> > — Profiles service
> > — SpringBootModuleService
> > — OsgiModuleService
> > — MicroprofileModuleService (not yet started)
> >
> > The framework is only started when the first OSGi module is deployed.
> >
> > If the user deploys only SpringBoot apps in Karaf, he won’t have any OSGi
> > framework.
> >
> > Is it what you expected ?
> >
> > On Karaf "launcher", we have services available (for now just using
> > karaf.getService("id")).
> >
> > I would love your feedback here. Thoughts ?
> >
> > Regards
> > JB
> >
> > > Le 24 mars 2021 à 19:03, Romain Manni-Bucau  a
> > écrit :
> > >
> > > Le mer. 24 mars 2021 à 17:35, Jean-Baptiste Onofre  a
> > > écrit :
> > >
> > >> Actually, spec like as DocuentBuilder would be rather a library,
> shared
> > by
> > >> all launchers.
> > >>
> > >
> > > Ok but what about jackson? the same?
> > >
> > > Joke apart what if spring-boot-app1 uses one impl and spring-boot-app2
> > uses
> > > another one?
> > >
> > > Think at the end there is the JVM, the framework stack which is
> isolated
> > > from the app and the apps or it does not move the ball very far from
> what
> > > we have today.
> > >
> > > Until there is it is EE server - in terms of architecture not
> scope/impl.
> > > But the gold of this solution is the ability to configure the leakage
> > > between layers/profiles to let an app override and potentially
> > > aggregate/share parts. Obvious example is the http service which can
> leak
> > > in spring boot app to override the servlet layer enabling to admistrate
> > it
> > > globally. Another more advanced solution is to deploy app1 and app2
> > called
> > > each other through a kafka topic and replace kafka stack by a local
> event
> > > (event admin or not is an impl detail), imagine the perf boost and
> admin
> > > simplicity it will bring - all that meaning saving a lot of green piece
> > of
> > > paper for managers ;).
> > >
> > > My only "?" as of today is: why OSGi, this technology is not really
> > needed
> > > for such a project (for ex this module provides it wihout OSGi
> > >
> >
> https://github.com/Talend/component-runtime/tree/master/container/container-core
> > )
> > > and can bring several drawbacks like the slowness to upgrade libs due
> to
> > > 

Re: [INFO] Apache Karaf 5 will be internally based on OSGi R8

[Romain Manni-Bucau]

in terms of arch yes, the key feature is to have a tree classloader and not
a graph (drops all the build complexity of OSGi and enable scanning
pluggability, yeah).
In terms of service since the launcher is a monolith it has the key
advantage to be able to scan all then dispatch so I guess we can just have
a ServiceLoader kind of SPI for "module service" impls and order them as
needed. a ModuleService { setModuleServiceRegistry(Registry); } would then
do the trick probably, no need of fancy IoC for such low level framework
IMHO.

Romain Manni-Bucau
@rmannibucau  |  Blog
 | Old Blog
 | Github  |
LinkedIn  | Book



Le mer. 24 mars 2021 à 19:13, Jean-Baptiste Onofre  a
écrit :

> Hi Romain,
>
> About OSGi, the way I did it (up to now), it’s as you describe:
>
> - Karaf "launcher"
> — Libraries service
> — Profiles service
> — SpringBootModuleService
> — OsgiModuleService
> — MicroprofileModuleService (not yet started)
>
> The framework is only started when the first OSGi module is deployed.
>
> If the user deploys only SpringBoot apps in Karaf, he won’t have any OSGi
> framework.
>
> Is it what you expected ?
>
> On Karaf "launcher", we have services available (for now just using
> karaf.getService("id")).
>
> I would love your feedback here. Thoughts ?
>
> Regards
> JB
>
> > Le 24 mars 2021 à 19:03, Romain Manni-Bucau  a
> écrit :
> >
> > Le mer. 24 mars 2021 à 17:35, Jean-Baptiste Onofre  a
> > écrit :
> >
> >> Actually, spec like as DocuentBuilder would be rather a library, shared
> by
> >> all launchers.
> >>
> >
> > Ok but what about jackson? the same?
> >
> > Joke apart what if spring-boot-app1 uses one impl and spring-boot-app2
> uses
> > another one?
> >
> > Think at the end there is the JVM, the framework stack which is isolated
> > from the app and the apps or it does not move the ball very far from what
> > we have today.
> >
> > Until there is it is EE server - in terms of architecture not scope/impl.
> > But the gold of this solution is the ability to configure the leakage
> > between layers/profiles to let an app override and potentially
> > aggregate/share parts. Obvious example is the http service which can leak
> > in spring boot app to override the servlet layer enabling to admistrate
> it
> > globally. Another more advanced solution is to deploy app1 and app2
> called
> > each other through a kafka topic and replace kafka stack by a local event
> > (event admin or not is an impl detail), imagine the perf boost and admin
> > simplicity it will bring - all that meaning saving a lot of green piece
> of
> > paper for managers ;).
> >
> > My only "?" as of today is: why OSGi, this technology is not really
> needed
> > for such a project (for ex this module provides it wihout OSGi
> >
> https://github.com/Talend/component-runtime/tree/master/container/container-core
> )
> > and can bring several drawbacks like the slowness to upgrade libs due to
> > meta, the blockers to add libs due to the lack of OSGi support, the
> > enforcement of architecture teams to adopt OSGi to use that solution etc.
> > Why not making OSGi a launcher as spring boot or microprofile, sounds to
> be
> > at the same level to me.
> >
> >
> >>
> >> I would rather say that Karaf 5 is a runtime in the way of launcher. If
> we
> >> consider an application server as launcher + some key turn features,
> then
> >> Karaf5 could be considered as an new light app server.
> >>
> >> You are right: for now, each spring boot app is in its own class loader,
> >> embedding its own spring version.
> >> However, a spring boot module (karaf 5 terminology uses module more than
> >> app) can use a profile. A profile basically brings a class loader where
> you
> >> can override spring boot module dependencies.
> >>
> >> Great questions: Karaf 5 MVP is a first attempt, it will be refine for
> >> sure. I just want to have a first running version to share with you all
> and
> >> chat about.
> >>
> >> Regards
> >> JB
> >>
> >>> Le 24 mars 2021 à 16:55, Grzegorz Grzybek  a
> >> écrit :
> >>>
> >>> Thanks for the insight ;)
> >>>
> >>> So first question that comes to my mind is - what will
> >>> `javax.xml.parsers.DocumentBuilderFactory#newInstance()` return? I
> guess
> >> it
> >>> depends on the layer.
> >>> If this will be (via java.util.ServiceLoader#load()) be configured at
> low
> >>> layer, we can have the "application server aspect"...
> >>>
> >>> Is "application server" view of Karaf 5 emphasized (existing at all?)
> >>> somehow?
> >>> Is Karaf 5 going to be a "deployment platform to run different kinds of
> >>> applications"?
> >>> For "Spring Boot applications classloaders" - will many "Spring Boot
> >>> Applications" be separated? If yes, then will each Spring Boot
> >> Application
> >>> 

Re: [INFO] Apache Karaf 5 will be internally based on OSGi R8

[Jean-Baptiste Onofre]

Hi Romain,

About OSGi, the way I did it (up to now), it’s as you describe:

- Karaf "launcher"
— Libraries service
— Profiles service
— SpringBootModuleService
— OsgiModuleService
— MicroprofileModuleService (not yet started)

The framework is only started when the first OSGi module is deployed.

If the user deploys only SpringBoot apps in Karaf, he won’t have any OSGi 
framework.

Is it what you expected ?

On Karaf "launcher", we have services available (for now just using 
karaf.getService("id")).

I would love your feedback here. Thoughts ?

Regards
JB

> Le 24 mars 2021 à 19:03, Romain Manni-Bucau  a écrit :
> 
> Le mer. 24 mars 2021 à 17:35, Jean-Baptiste Onofre  a
> écrit :
> 
>> Actually, spec like as DocuentBuilder would be rather a library, shared by
>> all launchers.
>> 
> 
> Ok but what about jackson? the same?
> 
> Joke apart what if spring-boot-app1 uses one impl and spring-boot-app2 uses
> another one?
> 
> Think at the end there is the JVM, the framework stack which is isolated
> from the app and the apps or it does not move the ball very far from what
> we have today.
> 
> Until there is it is EE server - in terms of architecture not scope/impl.
> But the gold of this solution is the ability to configure the leakage
> between layers/profiles to let an app override and potentially
> aggregate/share parts. Obvious example is the http service which can leak
> in spring boot app to override the servlet layer enabling to admistrate it
> globally. Another more advanced solution is to deploy app1 and app2 called
> each other through a kafka topic and replace kafka stack by a local event
> (event admin or not is an impl detail), imagine the perf boost and admin
> simplicity it will bring - all that meaning saving a lot of green piece of
> paper for managers ;).
> 
> My only "?" as of today is: why OSGi, this technology is not really needed
> for such a project (for ex this module provides it wihout OSGi
> https://github.com/Talend/component-runtime/tree/master/container/container-core)
> and can bring several drawbacks like the slowness to upgrade libs due to
> meta, the blockers to add libs due to the lack of OSGi support, the
> enforcement of architecture teams to adopt OSGi to use that solution etc.
> Why not making OSGi a launcher as spring boot or microprofile, sounds to be
> at the same level to me.
> 
> 
>> 
>> I would rather say that Karaf 5 is a runtime in the way of launcher. If we
>> consider an application server as launcher + some key turn features, then
>> Karaf5 could be considered as an new light app server.
>> 
>> You are right: for now, each spring boot app is in its own class loader,
>> embedding its own spring version.
>> However, a spring boot module (karaf 5 terminology uses module more than
>> app) can use a profile. A profile basically brings a class loader where you
>> can override spring boot module dependencies.
>> 
>> Great questions: Karaf 5 MVP is a first attempt, it will be refine for
>> sure. I just want to have a first running version to share with you all and
>> chat about.
>> 
>> Regards
>> JB
>> 
>>> Le 24 mars 2021 à 16:55, Grzegorz Grzybek  a
>> écrit :
>>> 
>>> Thanks for the insight ;)
>>> 
>>> So first question that comes to my mind is - what will
>>> `javax.xml.parsers.DocumentBuilderFactory#newInstance()` return? I guess
>> it
>>> depends on the layer.
>>> If this will be (via java.util.ServiceLoader#load()) be configured at low
>>> layer, we can have the "application server aspect"...
>>> 
>>> Is "application server" view of Karaf 5 emphasized (existing at all?)
>>> somehow?
>>> Is Karaf 5 going to be a "deployment platform to run different kinds of
>>> applications"?
>>> For "Spring Boot applications classloaders" - will many "Spring Boot
>>> Applications" be separated? If yes, then will each Spring Boot
>> Application
>>> "bring its own Spring"? Or will the Spring libraries be part of given
>> Karaf
>>> 5 release?
>>> 
>>> sorry for chaotic questions ;) But these are quite natural, assuming
>>> "single JVM process" by default (is it?)
>>> 
>>> regards
>>> Grzegorz Grzybek
>>> 
>>> śr., 24 mar 2021 o 16:46 Jean-Baptiste Onofre 
>> napisał(a):
>>> 
 Hi,
 
 Actually, you will have three class loader levels:
 
 - Level1: Karaf itself/Karaf services/libraries class loaders
 - Level2: profiles class loader
 - Level3: OSGi module running in the internal framework (inheriting
>> first
 level)
 - Level3: Spring Boot applications classloaders
 - Level3: other kind of applications (micro profile, …)
 
 So, basically, framework will be used for OSGi modules mostly.
 
 Today, launchers are "isolated", but I will implement bridges.
 
 Regards
 JB
 
> Le 24 mars 2021 à 15:37, Grzegorz Grzybek  a
 écrit :
> 
> Hello
> 
> OSGi Core R8 still assumes req/cap model[1] and resolution:
> 
> The Framework must resolve bundles.
>> 
> 
> If OSGi (and thus 

Re: [INFO] Apache Karaf 5 will be internally based on OSGi R8

[Jean-Baptiste Onofre]

Actually, spec like as DocuentBuilder would be rather a library, shared by all 
launchers.

I would rather say that Karaf 5 is a runtime in the way of launcher. If we 
consider an application server as launcher + some key turn features, then 
Karaf5 could be considered as an new light app server.

You are right: for now, each spring boot app is in its own class loader, 
embedding its own spring version.
However, a spring boot module (karaf 5 terminology uses module more than app) 
can use a profile. A profile basically brings a class loader where you can 
override spring boot module dependencies.

Great questions: Karaf 5 MVP is a first attempt, it will be refine for sure. I 
just want to have a first running version to share with you all and chat about.

Regards
JB

> Le 24 mars 2021 à 16:55, Grzegorz Grzybek  a écrit :
> 
> Thanks for the insight ;)
> 
> So first question that comes to my mind is - what will
> `javax.xml.parsers.DocumentBuilderFactory#newInstance()` return? I guess it
> depends on the layer.
> If this will be (via java.util.ServiceLoader#load()) be configured at low
> layer, we can have the "application server aspect"...
> 
> Is "application server" view of Karaf 5 emphasized (existing at all?)
> somehow?
> Is Karaf 5 going to be a "deployment platform to run different kinds of
> applications"?
> For "Spring Boot applications classloaders" - will many "Spring Boot
> Applications" be separated? If yes, then will each Spring Boot Application
> "bring its own Spring"? Or will the Spring libraries be part of given Karaf
> 5 release?
> 
> sorry for chaotic questions ;) But these are quite natural, assuming
> "single JVM process" by default (is it?)
> 
> regards
> Grzegorz Grzybek
> 
> śr., 24 mar 2021 o 16:46 Jean-Baptiste Onofre  napisał(a):
> 
>> Hi,
>> 
>> Actually, you will have three class loader levels:
>> 
>> - Level1: Karaf itself/Karaf services/libraries class loaders
>> - Level2: profiles class loader
>> - Level3: OSGi module running in the internal framework (inheriting first
>> level)
>> - Level3: Spring Boot applications classloaders
>> - Level3: other kind of applications (micro profile, …)
>> 
>> So, basically, framework will be used for OSGi modules mostly.
>> 
>> Today, launchers are "isolated", but I will implement bridges.
>> 
>> Regards
>> JB
>> 
>>> Le 24 mars 2021 à 15:37, Grzegorz Grzybek  a
>> écrit :
>>> 
>>> Hello
>>> 
>>> OSGi Core R8 still assumes req/cap model[1] and resolution:
>>> 
>>> The Framework must resolve bundles.
 
>>> 
>>> If OSGi (and thus resolution) is _internal_, what kind of "classpath"
>>> ("module path"?) will users see? Looking forward for 1-feet overview
>> of
>>> Karaf 5 ;)
>>> 
>>> Is Connect specification[2] the inherent part of Karaf5? Is "classpath"
>>> generally flat, hierarchical or irrelevant (?) by default?
>>> 
>>> Anyway - the future looks bright ;)
>>> 
>>> regards
>>> Grzegorz Grzybek
>>> ===
>>> [1]:
>>> 
>> https://docs.osgi.org/specification/osgi.core/8.0.0/framework.module.html#framework.module-resolving
>>> [2]:
>>> 
>> https://docs.osgi.org/specification/osgi.core/8.0.0/framework.connect.html
>>> 
>>> śr., 24 mar 2021 o 15:24 Jean-Baptiste Onofre 
>> napisał(a):
>>> 
 Hi guys,
 
 As you probably know, we are working on first Karaf 5 MVP, which is a
 complete Karaf refactoring.
 
 We will share some details soon, but I can already inform you that
 internally, it’s powered by OSGi R8 (but you will see that it’s more an
 internal point).
 
 Regards
 JB
>> 
>> 

Re: [INFO] Apache Karaf 5 will be internally based on OSGi R8

[Jean-Baptiste Onofre]

Hi,

Actually, you will have three class loader levels:

- Level1: Karaf itself/Karaf services/libraries class loaders
- Level2: profiles class loader 
- Level3: OSGi module running in the internal framework (inheriting first level)
- Level3: Spring Boot applications classloaders
- Level3: other kind of applications (micro profile, …)

So, basically, framework will be used for OSGi modules mostly.

Today, launchers are "isolated", but I will implement bridges.

Regards
JB

> Le 24 mars 2021 à 15:37, Grzegorz Grzybek  a écrit :
> 
> Hello
> 
> OSGi Core R8 still assumes req/cap model[1] and resolution:
> 
> The Framework must resolve bundles.
>> 
> 
> If OSGi (and thus resolution) is _internal_, what kind of "classpath"
> ("module path"?) will users see? Looking forward for 1-feet overview of
> Karaf 5 ;)
> 
> Is Connect specification[2] the inherent part of Karaf5? Is "classpath"
> generally flat, hierarchical or irrelevant (?) by default?
> 
> Anyway - the future looks bright ;)
> 
> regards
> Grzegorz Grzybek
> ===
> [1]:
> https://docs.osgi.org/specification/osgi.core/8.0.0/framework.module.html#framework.module-resolving
> [2]:
> https://docs.osgi.org/specification/osgi.core/8.0.0/framework.connect.html
> 
> śr., 24 mar 2021 o 15:24 Jean-Baptiste Onofre  napisał(a):
> 
>> Hi guys,
>> 
>> As you probably know, we are working on first Karaf 5 MVP, which is a
>> complete Karaf refactoring.
>> 
>> We will share some details soon, but I can already inform you that
>> internally, it’s powered by OSGi R8 (but you will see that it’s more an
>> internal point).
>> 
>> Regards
>> JB

Re: [INFO] Apache Karaf 5 will be internally based on OSGi R8

[Grzegorz Grzybek]

Hello

OSGi Core R8 still assumes req/cap model[1] and resolution:

The Framework must resolve bundles.
>

If OSGi (and thus resolution) is _internal_, what kind of "classpath"
("module path"?) will users see? Looking forward for 1-feet overview of
Karaf 5 ;)

Is Connect specification[2] the inherent part of Karaf5? Is "classpath"
generally flat, hierarchical or irrelevant (?) by default?

Anyway - the future looks bright ;)

regards
Grzegorz Grzybek
===
[1]:
https://docs.osgi.org/specification/osgi.core/8.0.0/framework.module.html#framework.module-resolving
[2]:
https://docs.osgi.org/specification/osgi.core/8.0.0/framework.connect.html

śr., 24 mar 2021 o 15:24 Jean-Baptiste Onofre  napisał(a):

> Hi guys,
>
> As you probably know, we are working on first Karaf 5 MVP, which is a
> complete Karaf refactoring.
>
> We will share some details soon, but I can already inform you that
> internally, it’s powered by OSGi R8 (but you will see that it’s more an
> internal point).
>
> Regards
> JB

[INFO] Apache Karaf 5 will be internally based on OSGi R8

[Jean-Baptiste Onofre]

Hi guys,

As you probably know, we are working on first Karaf 5 MVP, which is a complete 
Karaf refactoring.

We will share some details soon, but I can already inform you that internally, 
it’s powered by OSGi R8 (but you will see that it’s more an internal point).

Regards
JB