On Mar 29, 2012, at 10:06 AM, Vincent Massol wrote: > Transforming this thread in a brainstorming since we couldn't get to an > agreement quickly. Once it's settled I'll launch a second vote. > > See below. > > On Mar 29, 2012, at 8:20 AM, Vincent Massol wrote: > >> Hi Caleb, >> >> On Mar 28, 2012, at 11:28 PM, Caleb James DeLisle wrote: >> >>> >>> >>> On 03/28/2012 02:03 PM, Vincent Massol wrote: >>>> >>>> On Mar 28, 2012, at 7:10 PM, Denis Gervalle wrote: >>>> >>>>> On Wed, Mar 28, 2012 at 12:27, Vincent Massol <[email protected]> wrote: >>>>> >>>>>> Hi devs, >>>>>> >>>>>> I'd like to change our deprecation strategy. Here's what we are currently >>>>>> supposed to use (we voted it a long time ago): >>>>>> >>>>>> http://dev.xwiki.org/xwiki/bin/view/Community/DevelopmentPractices#HDeprecation26LegacyStrategy >>>>>> >>>>>> " >>>>>> In addition our rule is to keep @deprecated methods/classes for 2 final >>>>>> releases after the version where they were first added has been released >>>>>> as >>>>>> final. >>>>>> For example if a method is deprecated in, say XE 1.3M2 then the method >>>>>> will be removed in 1.6M1 or after. Of course any major new release can >>>>>> deprecate anything. For example a XWiki 2.0 release is allowed to break >>>>>> backward compatibility (obviously we need to be careful to offer a >>>>>> migration path for users of previous major versions). >>>>>> " >>>>>> >>>>>> Issues: >>>>>> * This seems a bit harsh to me for some of our users/devs in the >>>>>> community. >>>>>> * We're not following which proves to me it's not a good rule >>>>>> * It doesn't say anything about Scripting APIs which require a greater >>>>>> stability in order not to break all wiki pages >>>>>> >>>>>> Definition of a Scripting API: >>>>>> * a Script Service (that's the new way of providing script apis) >>>>>> * a class in the "api" package in xwiki-platform-oldcore (this is the old >>>>>> way of providing script apis) >>>>>> >>>>>> Thus I'd like to propose this new rule: >>>>>> >>>>>> * Deprecated methods can only be removed in the next Release Cycle. For >>>>>> example something deprecated in version N.x can be removed in version >>>>>> N+1.y >>>>>> where x and y can be anything. This is logical since N+1 means a new >>>>>> major >>>>>> release and it's common to understand that major releases have no >>>>>> guarantee >>>>>> of API compatibility (See >>>>>> http://en.wikipedia.org/wiki/Software_versioningfor example). >>>>>> * For scripting APIs we can remove deprecated API only after 4 Release >>>>>> Cycles. For example since we're in 4.x this means we >>>>> >>>>> >>>>> Why four ? isn't it too much ? >>>> >>>> The reason I proposed 4 is because nowadays there still are quite a few >>>> XWiki 1.x instances in the wild so if people have coded apps on 1.x and >>>> then upgrade to 4.0 (for ex) it would be nice if their app still works. >>>> However I think it's ok to not support apis done in 0.9. And next year it >>>> would be ok to drop 1.x api support, etc. >>>> >>>> It's long but then we can see in the wild that it's important we provide >>>> stable scripting apis for users since they're used a lot while java apis >>>> are used by more savvy user (developers) and thus having a shorter >>>> removing cycle for them (1 year) should be ok. >>>> >>>> What would you like to propose instead? >>> >>> I'd rather we had no hard rules lest dogmatic adherence to the rules >>> becomes an excuse not to fulfill our obligation to do what's best for the >>> software. >>> I'm not exactly sure what `break' means since there's no reason I can see >>> for these functions to be removed from the compatibility aspect. >> >> The reason for having a well-defined rule is: >> >> * I think it's better than having to send a vote every time we want to >> remove a deprecated api. It certainly is much simpler. >> * Publicly document it so that our users will know about this rule and adapt >> their deprecation replacement strategy as a consequence >> >> I really think we ought to publish our deprecation and removal policy. >> >>> I propose: >>> >>> #1 Move remaining deprecated scripting API methods from oldcore into >>> legacy-oldcore compatibility aspect. >>> That means these: >>> http://nexus.xwiki.org/nexus/service/local/repositories/releases/archive/org/xwiki/platform/xwiki-platform-oldcore/4.0-milestone-1/xwiki-platform-oldcore-4.0-milestone-1-javadoc.jar/!/index.html >> >> This is *already* our strategy, see the "2-step" strategy defined here: >> http://dev.xwiki.org/xwiki/bin/view/Community/DevelopmentPractices#HDeprecation26LegacyStrategy >> >> Everyone is already supposed to do this and do this regularly. The issue is >> that before being able to move a lot of code we need to fix a lot of >> deprecation usages. >> >> <OT>It could be nice to organize a "deprecation day" where we try to squash >> as many deprecation usages as possible</OT> >> >>> #2 Get xwiki-enterprise building and testing with xwiki-platform-oldcore >>> instead of xwiki-platform-legacy-oldcore. >>> Add an xwiki-enterprise-legacy-jetty-hsql build profile so that we can test >>> in parallel, with and without legacy-oldcore. >>> I ran the UI tests and it appears that we have a few dependencies on >>> legacy-oldcore. IMO this is very bad. >> >> This is very very bad and goes against our current policy indeed. >> >>> However it doesn't look like we have too many. >>> Lets get it running, see the failing tests, report the issues, then fix >>> them. >> >> This is a very good idea and I'm all for it. >> >>> #3 Stop shipping legacy-oldcore by default. Users can always swap >>> platform-oldcore for it on their own. >> >> It's not just oldcore, we have several legacy modules and theoretically we >> can have as many as we have modules. >> >> I don't think we cans stop shipping a distribution with legacy modules but >> what would be nice is to start shipping a distribution without legacy >> modules. We could even highlight this one as first listed to raise awareness. >> >>> #4 Aggressively move deprecated internal (non-script api) code into the >>> compatibility aspect, this will allow us to simplify the oldcore, and >>> potentially even remove dependencies. >> >> This is already our strategy. Again for some cases it's hard but I'm all for >> it. A lot of us introduce new APIs but don't update the code to use the new >> API creating a lot of deprecation usages suddenly. I'm all for this too. >> >>> If we want to stall, we can stall at #3, having 1, 2, and some of 4 taken >>> care of will make the final decision the flip of a switch. >> >> This is all great but it doesn't solve the VOTE. It's a different topic and >> something we've already VOTED and doing. I agree it would be nice to do it >> more aggressively but it's very different from the deprecation policy I'd >> like to find an agreement on. >> >> Unless I misunderstood you and your proposal is to NEVER remove deprecated >> APIs, which is a solution of course. I'm a bit afraid of the consequences. > > Actually this is not a bad idea. I've thought about it and couldn't find a > real blocker to this strategy of never removing deprecated APIs. Some > thoughts though: > > * When we remove a class to replace it with another one we need to invent a > mechanism in the main code to allow pluggability. Sometimes this is nice to > have but sometimes it's a bit contrived and it would be nice to remove this > pluggability when it's no longer needed. Not that bad though. > * We currently have no way to know if something in legacy is working since > we're not using it anymore :) The only solution I could think of would be to > add some functional tests to prove that these old apis still work.
* We need to introduce aspects in legacy modules other than oldcore. This is ok for me. Thanks -Vincent > So do we want to keep our deprecated APIs forever with a special vote each > time we really need to remove something from legacy? > > Thanks > -Vincent > >> BTW I'd like to update our current strategy documentation to a 3-step >> strategy: >> * Step 1: deprecate >> * Step 2: move to legacy modules (this means removing our usages of the >> deprecated apis) >> * Step 3: remove from legacy modules <-- This is what we're voting on here >> >> i.e. we could do step3 only when we've done steps 1 and 2 first. This is a >> good strategy IMO because it means that we would have done step2 which is >> required to be able to remove a deprecated api anyway… ;) >> >> Thanks >> -Vincent >> >>> Caleb >>> >>> >>> >>>> >>>> Thanks >>>> -Vincent >>>> >>>>>> can remove deprecated APIs from 0.x releases. And when we start 5.x we >>>>>> will be able to remove deprecated scripting apis deprecated in 1.x. >>>>>> >>>>>> Here's my +1 >>>>>> >>>>>> Thanks >>>>>> -Vincent > _______________________________________________ devs mailing list [email protected] http://lists.xwiki.org/mailman/listinfo/devs
