Sling on GAE
Hi guys, on may I'll meet one of the guys working on Google App Engine, and one of the things I would love to discuss with him is the use of the web-side of Sling on GAE. I would love to use Sling to access the Google Data Store and program user interface in an easy way. Now I know that, due to limitations on the GAE environment this will be really hard (I don't know how to make Felix run on there without writing files or launching threads), so I want to discuss this with Sling experts and know what do you think about the idea and if is something doable. Ciao. -- http://www.lucamasini.net http://twitter.com/lmasini http://www.linkedin.com/pub/luca-masini/7/10/2b9
Re: Sling on GAE
On Wed, Apr 14, 2010 at 20:00, Luca Masini wrote: > I would love to use Sling to access the Google Data Store and program user > interface in an easy way. Now I know that, due to limitations on the GAE > environment this will be really hard (I don't know how to make Felix run on > there without writing files or launching threads), so I want to discuss this > with Sling experts and know what do you think about the idea and if is > something doable. So you would want to use Sling directly on top of the Google Data Store and not use JCR? In theory this should be possible, but might require additional work besides the basic issues like multiple threads, running an OSGi framework etc. Many things in Sling work based on a JCR repository. You can build a resource tree based on other backends, but this is a bit like reinventing the wheel. If JCR should be used as well on GAE below Sling, this also requires changes to Jackrabbit: first a datastore/persistence manager using the google data store as backend and secondly removing all background threads in Jackrabbit. See also http://wiki.apache.org/jackrabbit/JackrabbitOnCloud or the discussion at http://markmail.org/thread/n4redkdzyxaval7r I think it would be easier if the GAE guys would remove some of the constraints to allow for infrastructure apps. Maybe you can persuade them ;-) Regards, Alex -- Alexander Klimetschek alexander.klimetsc...@day.com
Re: Sling on GAE
I think there are no chances to run JackRabbit on GAE, for now, and less that I can persuade them to let application create thread or files :) But I'm happy to read that for you too can be a way to use Sling directly, may be using a ResourceResolver on top of the DataStore or implementing a simple Level 1 JCR Repository. That can be a way ??? On Wed, Apr 14, 2010 at 9:51 PM, Alexander Klimetschek wrote: > On Wed, Apr 14, 2010 at 20:00, Luca Masini wrote: > > I would love to use Sling to access the Google Data Store and program > user > > interface in an easy way. Now I know that, due to limitations on the GAE > > environment this will be really hard (I don't know how to make Felix run > on > > there without writing files or launching threads), so I want to discuss > this > > with Sling experts and know what do you think about the idea and if is > > something doable. > > So you would want to use Sling directly on top of the Google Data > Store and not use JCR? In theory this should be possible, but might > require additional work besides the basic issues like multiple > threads, running an OSGi framework etc. Many things in Sling work > based on a JCR repository. You can build a resource tree based on > other backends, but this is a bit like reinventing the wheel. > > If JCR should be used as well on GAE below Sling, this also requires > changes to Jackrabbit: first a datastore/persistence manager using the > google data store as backend and secondly removing all background > threads in Jackrabbit. See also > http://wiki.apache.org/jackrabbit/JackrabbitOnCloud or the discussion > at http://markmail.org/thread/n4redkdzyxaval7r > > I think it would be easier if the GAE guys would remove some of the > constraints to allow for infrastructure apps. Maybe you can persuade > them ;-) > > Regards, > Alex > > -- > Alexander Klimetschek > alexander.klimetsc...@day.com > -- http://www.lucamasini.net http://twitter.com/lmasini http://www.linkedin.com/pub/luca-masini/7/10/2b9
Re: Sling on GAE
Hi, On 14.04.2010 22:34, Luca Masini wrote: > I think there are no chances to run JackRabbit on GAE, for now, and less > that I can persuade them to let application create thread or files :) > > But I'm happy to read that for you too can be a way to use Sling directly, > may be using a ResourceResolver on top of the DataStore or implementing a > simple Level 1 JCR Repository. > > That can be a way ??? Well, unless Google removes the Thread creation restriction, there is no way of running Sling (or Jackrabbit by that matter) on GAE. Sad, but true. Now for accessing google store: It may well be possible (and depending on use cases) simpler to implement a ResourceProvider for DataStore than it is to implement a Repository backend. In fact, hard requirements on JCR is very limited (though important) in Sling. One is the Sling POST Servlet and another one is the class writer which is used to write back JSP class files. But there are discussions around completing support for basic CRUD. What we currently have is read support (of course ;-) ) and update support by means of the PersistableValueMap. We are missing support to create resources and to remove resources. Regards Felix > > On Wed, Apr 14, 2010 at 9:51 PM, Alexander Klimetschek > wrote: > >> On Wed, Apr 14, 2010 at 20:00, Luca Masini wrote: >>> I would love to use Sling to access the Google Data Store and program >> user >>> interface in an easy way. Now I know that, due to limitations on the GAE >>> environment this will be really hard (I don't know how to make Felix run >> on >>> there without writing files or launching threads), so I want to discuss >> this >>> with Sling experts and know what do you think about the idea and if is >>> something doable. >> >> So you would want to use Sling directly on top of the Google Data >> Store and not use JCR? In theory this should be possible, but might >> require additional work besides the basic issues like multiple >> threads, running an OSGi framework etc. Many things in Sling work >> based on a JCR repository. You can build a resource tree based on >> other backends, but this is a bit like reinventing the wheel. >> >> If JCR should be used as well on GAE below Sling, this also requires >> changes to Jackrabbit: first a datastore/persistence manager using the >> google data store as backend and secondly removing all background >> threads in Jackrabbit. See also >> http://wiki.apache.org/jackrabbit/JackrabbitOnCloud or the discussion >> at http://markmail.org/thread/n4redkdzyxaval7r >> >> I think it would be easier if the GAE guys would remove some of the >> constraints to allow for infrastructure apps. Maybe you can persuade >> them ;-) >> >> Regards, >> Alex >> >> -- >> Alexander Klimetschek >> alexander.klimetsc...@day.com >> > > >
