Hi David/Christian, Here is what Mark wrote, that didn't make it:
"Quiesce is about stopping a bundle gracefully prior to its uninstallation, which is why we've had no need to implement a 'restart' capability. We currently use Apache Aries quiesce within IBM WebSphere Application Server. It's used in a scenario where an administrator is replacing some of the bundles within a running application. The code has been in use in that product for some years now so yes, I'm sorry but we do have a definite need for the facility." Essentially, we use it to notify containers/extenders of bundles that are about to be uninstalled (prior to that actually being done) so they can perform house-keeping ahead of uninstallation being kicked off. Regards, Graham. On 12 February 2015 at 10:12, David Bosschaert <david.bosscha...@gmail.com> wrote: > I'd like to understand what the use-case for the Quiesce functionality > actually is. Graham, would you like to explain the actual benefit that > it provides? > Once we understand that better, maybe we can think of a structure that > maintains Quiesce support with less complication in the code... > > Cheers, > > David > > On 12 February 2015 at 10:30, Graham Charters <gchart...@gmail.com> wrote: > > Hi Christian, > > > > Apologies for not responding sooner, Mark Nuttall tried to reply on this > > thread, but his email did not make it. We use Quiesce support in > WebSphere > > so need this to be left in. Please do not remove it. Many thanks. > > > > Graham. > > > > On 12 February 2015 at 08:02, Christian Schneider < > ch...@die-schneider.net> > > wrote: > > > >> I created an issue to track the removal of the quiesce support in aries > >> jpa. > >> https://issues.apache.org/jira/browse/ARIES-1297 > >> > >> I have prepared a commit and plan to apply the removal on next monday if > >> no one opposes. > >> > >> Christian > >> > >> > >> On 10.02.2015 09:15, Christian Schneider wrote: > >> > >>> In several places in aries we support the Quiesce API. As far as I > >>> understood its purpose is to shut down bundles without actually > stopping > >>> them. It does not seem to be any standard as the interfaces are in the > >>> Aries namespace. > >>> > >>> The problem with it is that it complicates the code a lot. For example > in > >>> jpa container we create a proxy for each EntityManager that also > supports > >>> quiesce methods even though they are > >>> not part of the EntityManager interface. The code in other modules is > >>> similarly affected. > >>> > >>> Besides this I do not see anyone using the API. I am also not sure why > we > >>> need it at all as OSGi already has nice lifecycle methods to stop > bundles > >>> which should have a similar effect if implemented nicely. One other > >>> disadvantge of Quiesce is that you can only shut down a bundle. You > can not > >>> restart it again. > >>> > >>> So the question is: Do we really need to support the Quiesce API? The > >>> code would be a lot less complex and error prone without it. > >>> > >>> WDYT? > >>> > >>> Christian > >>> > >>> > >>> > >> > >> -- > >> Christian Schneider > >> http://www.liquid-reality.de > >> > >> Open Source Architect > >> http://www.talend.com > >> > >> >
