On 9/22/10 14:44, Richard S. Hall wrote:
Hopefully, I can get some quick feedback on this since I want to do a
release...
Guillaume and I were discussing alternatives to a mandatory attribute.
An alternative idea was mark all provisional API as deprecated, so
clients get warnings. What are people's thoughts on the two approaches?
1. The benefit of using mandatory attributes on provisional API is
that you have to explicitly "opt in" to use it so no one can ever
claim they didn't know it was provisional.
2. The benefit of using deprecated tags is that it works more
smoothly with tooling and at still does give some sort of warning
notice, although less direct.
Personally, i still favor using mandatory attributes, because I think
it better captures our use case. But, I'd like to hear what other
people think.
Tom Watson (of Equinox fame) pointed out that using both is probably the
best option because only using mandatory attributes doesn't address
Require-Bundle, which could use the packages freely without opting in.
Otherwise, he feels the same way I do, that mandatory attributes are a
good idea (just like for split packages), because you really need to
know what you are doing to use the packages...
Given the fact that I really need to get a release of Gogo trunk out the
door, I'm just going to push forward for now with what we have in trunk,
which is using mandatory attributes. We can continue to refine our
policy and when we are done, we can do another release to reflect it
even if it means doing another one next week.
So, to summarize, we now have three options:
1. Just mandatory attributes.
2. Just deprecated tags.
3. Both.
After Tom's arguments, I'm probably now leaning toward #3.
-> richard
Quickly. :-)
-> richard
On 9/22/10 9:19, Richard S. Hall wrote:
On 9/22/10 6:16, Guillaume Nodet wrote:
I'm also not convinced by the mandatory attribute. I do understand
the value, but it may cause a lot of burden on our users for not much.
If you have another recommendation for making it 100% clear to our
users that these packages will not be supported in the future, then
speak up. It's not that I want to use mandatory attributes, it's that
I don't want to be taken to task in the future for throwing away the
API. In that regard, I think there is benefit to using it since
people have to go out of their way to use it.
Regarding the version number, I was using 0.6.1 because it is only a
maintenance release as compared to 0.6.0. The completely incompatible
change was from 0.4.0 to 0.6.0, no? Or are you specifically referring
to the mandatory attribute? If so, I don't have an issue with it
being 0.8.0 if you think the mandatory attribute warrants it, but I
don't really think that constitutes a breaking code
change...certainly a breaking metadata change.
-> richard
Mandatory attributes are not very common and the tooling might not be
prepared to handle those gracefully. For example, I've just hit a big
problem with karaf integration tests that use pax-exam, because the
mandatory attribute it not automatically added, so all test bundles
were failing during resolution ...
I've fixed that, but an average user will be in a real trouble if
hitting this.
On Wed, Sep 22, 2010 at 08:29, Guillaume Nodet<[email protected]>
wrote:
Do you plan to release gogo as 0.6.1 as indicated in JIRA ?
Given the change is fully incompatible, I'd at least bump the minor
version ...
On Mon, Sep 20, 2010 at 17:50, Richard S.
Hall<[email protected]> wrote:
On 9/20/10 11:21, Derek Baum wrote:
I also favor #1.
When we apply this to gogo, it will mean removing the draft
RFC-147 API
from
the org.osgi.service.command namespace and moving it to a felix
namespace.
We actually already did this for the gogo-0.6 release, but then
reverted
the
change in the trunk, as it broke many command providers who imported
org.osgi.service.command. Back then we didn't have a policy for
supporting
draft OSGi APIs, but now it seems like we've agreed on #1. Do we
need a
vote?
It sounds like we have consensus, so we can probably just move
forward.
-> richard
Derek
On 19 September 2010 17:27, Richard S.
Hall<[email protected]> wrote:
On 9/18/10 10:34, Felix Meschberger wrote:
Hi,
While I understand (and certainly don't underestimate the
consequences
of) the drawbacks of option (1) I still think it is the better
option.
At the time the OSGi releases the official API, we can still
keep our
internal API for certain period of time thus supporting both
API, if we
so wish.
From my point of view we should just export the packages with
mandatory
attributes and make it clear they will change when the API goes
final.
For
framework, I wouldn't plan to provide any ongoing support for
provisional
API. However, I don't think we need to mandate a global Felix
policy for
this and subprojects can choose to support two APIs if they want.
-> richard
Regards
Felix
Am 17.09.2010 18:35, schrieb Richard S. Hall:
For a long time, we've played a little fast and loose with our
handling
of provisional OSGi API. Starting with the OBR 1.6.0 and Gogo
0.6.0
releases, we've started to evolve a policy on how to handle
this, but
nothing has been decided concretely. This is problematic since
it leads
different people to different decisions. Thus, its about time we
defined
our policy on this.
So, what's the issue?
Provisional OSGi API is not official. Further, provisional
package
content is evolving and these changes are not always made readily
available by the OSGi Alliance. Even though some of us are
members of
the OSGi Alliance, we are not necessarily at liberty to disclose
changes
to internal RFCs.
So, what can we do about it?
I see two potential [reasonable] policies from which we could
choose:
1. Always use the org.apache.felix package namespace for
provisional
OSGi API until the spec goes final.
2. Use the org.osgi package namespace while the provisional
API is in
development, but only expose what has been publicly made
available
by the OSGi Alliance.
Both approaches have their drawbacks.
The benefit of (1) is that the legal/IP/etiquette issues and/or
concerns
are reduced to those associated with normal open source
development.
For
completely new development, like Gogo, this would all happen in
non-OSGi
packages, while changes to existing packages would need to be
done in
subclasses in non-OSGi packages. One downside of (1) is that
it will
always result in a package name change at the end that will break
existing clients. For this reason, such experimental packages
should be
exported with mandatory attributes to warn potential clients.
The benefit of (2) is that the package namespace is more
consistent.
The
downside of (2) is that it is a IP/legal/etiquette gray area
as to
whether or not we can do official releases of subprojects
containing
provisional OSGi API. Even if we do not modify the API, it
still is
potentially confusing to our users who are getting an "official"
release
from us of a subproject containing these "unofficial" bytes. At a
minimum we would also need to use deprecated tags and/or
mandatory
attributes to warn people. Even then, it still raises issues
since we
aren't at liberty to evolve the packages freely to include OSGi
internal, non-public RFC updates, nor extensions for potential
feedback
into the RFC. In those cases, we would still need to resort to
putting
stuff in org.apache.felix packages and renaming later once the
changes
become public, which would also be problematic for clients.
Also, you
have to consider the case where the RFC is abandoned, in which
case if
we still find it useful, we'll be forced to change our package
names.
From my point of view, approach (1) might not be awesome,
but it
results
in a simpler process than (2). So, I'd recommend (1). If the
majority
prefers (2), then we can do that (although I think we'll have
to run
the
decision by the board first).
Thoughts?
-> richard
--
Cheers,
Guillaume Nodet
------------------------
Blog: http://gnodet.blogspot.com/
------------------------
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http://fusesource.com
