Re: [Modularity] Module streams with two different, non-overlapping, package sets?
Le jeudi 21 juin 2018 à 18:55 +0200, Mikolaj Izdebski a écrit : > > Allowing parallel installation of two distinct package sets, provided > that they don't conflict in any way - how is that impossible? I get > that it's not a goal for modularity to support this, but I don't see > any technical reason not to allow it. It's the usual leaf vs trunk dilemma. Everyone wants to be treated as a leaf (top of the ecosystem), but free software is deeply interlinked, and you get complexity explosion as soon as you allow alternative links. Regards, -- Nicolas Mailhot ___ devel mailing list -- devel@lists.fedoraproject.org To unsubscribe send an email to devel-le...@lists.fedoraproject.org Fedora Code of Conduct: https://getfedora.org/code-of-conduct.html List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org/message/2S4AIZXIOLF3GAUMJGN664SHK3MUSKTA/
Re: [Modularity] Module streams with two different, non-overlapping, package sets?
On Thu, Jun 21, 2018 at 06:55:54PM +0200, Mikolaj Izdebski wrote: > On 06/21/2018 06:26 PM, Stephen Gallagher wrote: > >>> So, when we started looking at ways to provide alternative software, we > >>> determined that parallel-installation was a non-goal. Not needing to > >> solve > >>> an unsolvable problem meant that we could focus on the parts that really > >>> matter: allowing people to select which single version of the software > >>> meets their needs. > >> > >> So the conclusion is that inability to have parallel-installable streams > >> of the same module is not due to technical difficulties to implement > >> that feature, but rather a consequence of prioritizing different > >> requirements. > >> > >> > > You drew a conclusion that is EXACTLY the opposite of what I said above. We > > determined that parallel-installation was basically impossible to build in > > a generic way. Once that was eliminated as a possible requirement, the rest > > fell into place fairly neatly. > > Allowing parallel installation of two distinct package sets, provided > that they don't conflict in any way - how is that impossible? I get > that it's not a goal for modularity to support this, but I don't see any > technical reason not to allow it. If those package sets are completely distinct, most of the arguments Stephen provided indeed don't apply, however, you still need to thoroughly check that your module and all of its dependencies are installable in this scenario and you need to be able to do that in the buildroot as well. That includes both modular and ursine buildroot. Furthermore you need to come up with a new tracking mechanism in the software database as well as usable UI and APIs. All this for only a small set of modules that could easily delivery via some other method. A generic solution appears to be impossible. This kind of a limited solution can be done but as I said earlier, it's not currently on the agenda. P signature.asc Description: PGP signature ___ devel mailing list -- devel@lists.fedoraproject.org To unsubscribe send an email to devel-le...@lists.fedoraproject.org Fedora Code of Conduct: https://getfedora.org/code-of-conduct.html List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org/message/JMDBJKW2JXPAGLDJKBCAOW5AKYIKXEFM/
Re: [Modularity] Module streams with two different, non-overlapping, package sets?
On 06/21/2018 06:26 PM, Stephen Gallagher wrote: >>> So, when we started looking at ways to provide alternative software, we >>> determined that parallel-installation was a non-goal. Not needing to >> solve >>> an unsolvable problem meant that we could focus on the parts that really >>> matter: allowing people to select which single version of the software >>> meets their needs. >> >> So the conclusion is that inability to have parallel-installable streams >> of the same module is not due to technical difficulties to implement >> that feature, but rather a consequence of prioritizing different >> requirements. >> >> > You drew a conclusion that is EXACTLY the opposite of what I said above. We > determined that parallel-installation was basically impossible to build in > a generic way. Once that was eliminated as a possible requirement, the rest > fell into place fairly neatly. Allowing parallel installation of two distinct package sets, provided that they don't conflict in any way - how is that impossible? I get that it's not a goal for modularity to support this, but I don't see any technical reason not to allow it. -- Mikolaj Izdebski Senior Software Engineer, Red Hat IRC: mizdebsk ___ devel mailing list -- devel@lists.fedoraproject.org To unsubscribe send an email to devel-le...@lists.fedoraproject.org Fedora Code of Conduct: https://getfedora.org/code-of-conduct.html List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org/message/JIYXGHBSF6GETDJTLSC2EZ3CB62KIOD5/
Re: [Modularity] Module streams with two different, non-overlapping, package sets?
On Thu, Jun 21, 2018 at 11:56 AM Mikolaj Izdebski wrote: > On 06/20/2018 04:15 PM, Stephen Gallagher wrote: > > On Wed, Jun 20, 2018 at 10:06 AM Mikolaj Izdebski > > wrote: > > > >> On 06/20/2018 02:30 PM, Petr Šabata wrote: > >>> Parallel installation of streams on a single system indeed > >>> isn't supported at this point and isn't planned anytime in the > >>> near future. In general it's a more complicated problem than > >>> it might seem at first. > >> > >> Could you elaborate and explain what's so complicated about it? > >> > > > > The short answer is that there exists no generic solution for > > parallel-installation. Many packages rely on well-known resources[1] and > > cannot be parallel-installed at all. Other packages *may* support > > parallel-installation but consumers must take special steps to enable > > support for it. > > In general case, when packages conflict, I would agree. But as subject > says, this is about a special case - non-overlapping, non-conflicting > package sets, which can be installed in parallel without taking any > special steps, like java-1.8.0-openjdk and java-11-openjdk that were > brought up in the first message. > > Yes, but in order to support that in Modularity, we would need a general-case solution that would work for all packages. Just because *some* RPMs don't conflict between versions doesn't mean that a generic solution can be built for all RPMs. > > I don't have a good link right now, but folks at Red Hat did a number of > > customer studies and determined that in real-world deployments, > > parallel-installation was very rarely used. Generally, the OS was > > established with a standard set of packages and then anything that needed > > an alternate version was deployed as a VM or container. > > Some packages are designed to be parallel-installable for a reason - > because users expect and require that. OpenJDK is an example of such > package. Even different version-releases of the same component can be, > by design, installed in parallel. > > Sure, and that's why we recommend that in THIS case, you would probably build a separate module (or use standard RPMs) instead. > > So, when we started looking at ways to provide alternative software, we > > determined that parallel-installation was a non-goal. Not needing to > solve > > an unsolvable problem meant that we could focus on the parts that really > > matter: allowing people to select which single version of the software > > meets their needs. > > So the conclusion is that inability to have parallel-installable streams > of the same module is not due to technical difficulties to implement > that feature, but rather a consequence of prioritizing different > requirements. > > You drew a conclusion that is EXACTLY the opposite of what I said above. We determined that parallel-installation was basically impossible to build in a generic way. Once that was eliminated as a possible requirement, the rest fell into place fairly neatly. ___ devel mailing list -- devel@lists.fedoraproject.org To unsubscribe send an email to devel-le...@lists.fedoraproject.org Fedora Code of Conduct: https://getfedora.org/code-of-conduct.html List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org/message/IUE4AYMCCIFI74STTB45GVCK6Y24VU2T/
Re: [Modularity] Module streams with two different, non-overlapping, package sets?
On 06/20/2018 04:15 PM, Stephen Gallagher wrote: > On Wed, Jun 20, 2018 at 10:06 AM Mikolaj Izdebski > wrote: > >> On 06/20/2018 02:30 PM, Petr Šabata wrote: >>> Parallel installation of streams on a single system indeed >>> isn't supported at this point and isn't planned anytime in the >>> near future. In general it's a more complicated problem than >>> it might seem at first. >> >> Could you elaborate and explain what's so complicated about it? >> > > The short answer is that there exists no generic solution for > parallel-installation. Many packages rely on well-known resources[1] and > cannot be parallel-installed at all. Other packages *may* support > parallel-installation but consumers must take special steps to enable > support for it. In general case, when packages conflict, I would agree. But as subject says, this is about a special case - non-overlapping, non-conflicting package sets, which can be installed in parallel without taking any special steps, like java-1.8.0-openjdk and java-11-openjdk that were brought up in the first message. > I don't have a good link right now, but folks at Red Hat did a number of > customer studies and determined that in real-world deployments, > parallel-installation was very rarely used. Generally, the OS was > established with a standard set of packages and then anything that needed > an alternate version was deployed as a VM or container. Some packages are designed to be parallel-installable for a reason - because users expect and require that. OpenJDK is an example of such package. Even different version-releases of the same component can be, by design, installed in parallel. > So, when we started looking at ways to provide alternative software, we > determined that parallel-installation was a non-goal. Not needing to solve > an unsolvable problem meant that we could focus on the parts that really > matter: allowing people to select which single version of the software > meets their needs. So the conclusion is that inability to have parallel-installable streams of the same module is not due to technical difficulties to implement that feature, but rather a consequence of prioritizing different requirements. -- Mikolaj Izdebski Senior Software Engineer, Red Hat IRC: mizdebsk ___ devel mailing list -- devel@lists.fedoraproject.org To unsubscribe send an email to devel-le...@lists.fedoraproject.org Fedora Code of Conduct: https://getfedora.org/code-of-conduct.html List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org/message/WMAO2HRVCJMP23NL6XKYPZFPCULY6FF3/
Re: [Modularity] Module streams with two different, non-overlapping, package sets?
On Wed, Jun 20, 2018 at 10:06 AM Mikolaj Izdebski wrote: > On 06/20/2018 02:30 PM, Petr Šabata wrote: > > Parallel installation of streams on a single system indeed > > isn't supported at this point and isn't planned anytime in the > > near future. In general it's a more complicated problem than > > it might seem at first. > > Could you elaborate and explain what's so complicated about it? > The short answer is that there exists no generic solution for parallel-installation. Many packages rely on well-known resources[1] and cannot be parallel-installed at all. Other packages *may* support parallel-installation but consumers must take special steps to enable support for it. I don't have a good link right now, but folks at Red Hat did a number of customer studies and determined that in real-world deployments, parallel-installation was very rarely used. Generally, the OS was established with a standard set of packages and then anything that needed an alternate version was deployed as a VM or container. So, when we started looking at ways to provide alternative software, we determined that parallel-installation was a non-goal. Not needing to solve an unsolvable problem meant that we could focus on the parts that really matter: allowing people to select which single version of the software meets their needs. [1] I can't install two packages that try to serve the same well-known D-BUS name or both provide a local DNS cache, for example. I can't install two packages that both own the same executable name without using the "alternatives" system. I can't install two versions of a package that provide a shared object plugin with the same name. And so on and so forth. All of these have possible solutions, but no single generic solution exists. In the general case, we figure that the triumvirate of modules, containers and VMs solves this problem for 99% of cases. The remaining exception cases have to be dealt with individually. ___ devel mailing list -- devel@lists.fedoraproject.org To unsubscribe send an email to devel-le...@lists.fedoraproject.org Fedora Code of Conduct: https://getfedora.org/code-of-conduct.html List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org/message/QPBLGCRRG2XRV4GRKUGTL35CGM7KSYFX/
Re: [Modularity] Module streams with two different, non-overlapping, package sets?
On 06/20/2018 02:30 PM, Petr Šabata wrote: > Parallel installation of streams on a single system indeed > isn't supported at this point and isn't planned anytime in the > near future. In general it's a more complicated problem than > it might seem at first. Could you elaborate and explain what's so complicated about it? -- Mikolaj Izdebski Senior Software Engineer, Red Hat IRC: mizdebsk ___ devel mailing list -- devel@lists.fedoraproject.org To unsubscribe send an email to devel-le...@lists.fedoraproject.org Fedora Code of Conduct: https://getfedora.org/code-of-conduct.html List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org/message/ZLLYSBTZSAFZP2YR4VYUPTVEKFZRQNY7/
Re: [Modularity] Module streams with two different, non-overlapping, package sets?
On Wed, Jun 20, 2018 at 02:15:00PM +0200, Severin Gehwolf wrote:
> On Wed, 2018-06-20 at 07:59 -0400, Josh Boyer wrote:
> > On Wed, Jun 20, 2018 at 7:52 AM Severin Gehwolf wrote:
> > >
> > > Hi,
> > >
> > > I'm exploring the Fedora Modularity world and would like to know
> > > whether it's possible to have two different module streams install two
> > > different sets of packages? If that's possible, would installing one
> > > stream remove the packages from the other stream even though the set of
> > > packages don't overlap? I'm aware that it's not a goal of modularity to
> > > support parallel installability. But what if the packages themselves
> > > already allow parallel installability?
> > >
> > > Example:
> > >
> > > Module name: jdk
> > > Streams: 8, 11
> > >
> > > 1) "dnf module install jdk:8/default" installs these packages:
> > >
> > > java-1.8.0-openjdk
> > > java-1.8.0-openjdk-devel
> > > java-1.8.0-openjdk-headless
> > >
> > > 2) "dnf module install jdk:11/default" installs these packages:
> > >
> > > java-11-openjdk
> > > java-11-openjdk-headless
> > > java-11-openjdk-devel
> > >
> > > After 1) *and* 2) would I have both module streams' packages on my
> > > system? Would I have only the set from 2) with 1) removed?
> >
> > I think you would only have the set from 2.
> >
> > Parallel installation can't be done via streams, so it must be done at
> > the module level. So you'd have jdk8 and jdk11 modules, each with a
> > default stream. Given the default is specified, an installation would
> > look something like:
> >
> > "dnf module install jdk8; dnf module install jdk11"
>
> That's interesting, thanks!
>
> FWIW, I've tried the reverse :) I had jdk10 and jdk11 both specifying
> packages java-openjdk{,-devel,-headless} and the install of jdk11
> *upgraded* packages from the other (jdk10) module.
You could still do it with streams and simply encourage users
who need both to use containers, one with each stream stream
enabled :)
Parallel installation of streams on a single system indeed
isn't supported at this point and isn't planned anytime in the
near future. In general it's a more complicated problem than
it might seem at first.
P
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Re: [Modularity] Module streams with two different, non-overlapping, package sets?
On Wed, 2018-06-20 at 07:59 -0400, Josh Boyer wrote:
> On Wed, Jun 20, 2018 at 7:52 AM Severin Gehwolf wrote:
> >
> > Hi,
> >
> > I'm exploring the Fedora Modularity world and would like to know
> > whether it's possible to have two different module streams install two
> > different sets of packages? If that's possible, would installing one
> > stream remove the packages from the other stream even though the set of
> > packages don't overlap? I'm aware that it's not a goal of modularity to
> > support parallel installability. But what if the packages themselves
> > already allow parallel installability?
> >
> > Example:
> >
> > Module name: jdk
> > Streams: 8, 11
> >
> > 1) "dnf module install jdk:8/default" installs these packages:
> >
> > java-1.8.0-openjdk
> > java-1.8.0-openjdk-devel
> > java-1.8.0-openjdk-headless
> >
> > 2) "dnf module install jdk:11/default" installs these packages:
> >
> > java-11-openjdk
> > java-11-openjdk-headless
> > java-11-openjdk-devel
> >
> > After 1) *and* 2) would I have both module streams' packages on my
> > system? Would I have only the set from 2) with 1) removed?
>
> I think you would only have the set from 2.
>
> Parallel installation can't be done via streams, so it must be done at
> the module level. So you'd have jdk8 and jdk11 modules, each with a
> default stream. Given the default is specified, an installation would
> look something like:
>
> "dnf module install jdk8; dnf module install jdk11"
That's interesting, thanks!
FWIW, I've tried the reverse :) I had jdk10 and jdk11 both specifying
packages java-openjdk{,-devel,-headless} and the install of jdk11
*upgraded* packages from the other (jdk10) module.
Cheers,
Severin
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Re: [Modularity] Module streams with two different, non-overlapping, package sets?
On Wed, Jun 20, 2018 at 7:52 AM Severin Gehwolf wrote: > > Hi, > > I'm exploring the Fedora Modularity world and would like to know > whether it's possible to have two different module streams install two > different sets of packages? If that's possible, would installing one > stream remove the packages from the other stream even though the set of > packages don't overlap? I'm aware that it's not a goal of modularity to > support parallel installability. But what if the packages themselves > already allow parallel installability? > > Example: > > Module name: jdk > Streams: 8, 11 > > 1) "dnf module install jdk:8/default" installs these packages: > > java-1.8.0-openjdk > java-1.8.0-openjdk-devel > java-1.8.0-openjdk-headless > > 2) "dnf module install jdk:11/default" installs these packages: > > java-11-openjdk > java-11-openjdk-headless > java-11-openjdk-devel > > After 1) *and* 2) would I have both module streams' packages on my > system? Would I have only the set from 2) with 1) removed? I think you would only have the set from 2. Parallel installation can't be done via streams, so it must be done at the module level. So you'd have jdk8 and jdk11 modules, each with a default stream. Given the default is specified, an installation would look something like: "dnf module install jdk8; dnf module install jdk11" josh ___ devel mailing list -- devel@lists.fedoraproject.org To unsubscribe send an email to devel-le...@lists.fedoraproject.org Fedora Code of Conduct: https://getfedora.org/code-of-conduct.html List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org/message/GOP2JOA6SE7YG4K3JV75VKT537ZZRP3Y/
