Hi Marcel, 2 cents..
2011/9/29 Marcel Offermans <[email protected]>: > There are two issues related to multi-tenancy I want to discuss: > 1) The current multi-tenancy development model is too invasive for > developers. Everything must become a factory, and worse, it's impossible to > use 99% of all existing OSGi services because they don't support this model. > I think it ultimately hurts adoption of Amdatu, because you can't just use > OSGi. I agree that the current model is too invasive and brittle. Ideally an amdatu application developer should not be concerned with multi-tenancy at all. In previous discussions and milestone definitions I believe we have used "restoring the programming model". There have bee mentions of smart base activators or dependency manager constructs that could help out. However, such solution are still too invasive for the second part your second point. How to manage "amdatu unaware" implementations in a multi-tenant model... > 2) Multi-tenancy should be optional. That means that all services should > operate as "normal" services when there are no tenants around and only start > supporting tenants when the appropriate tenant bundles are installed. What s wrong with a "Default Tenant" approach? My concerns is all kinds of implementations popping up that can not handle multi tenancy and it will be choas. However, given a full solution to point 1 we have no argument. The application developer and 3rd party code) should be unaware and thus not care ;) > I understand that the current model is used, so we cannot just "throw it > away". It is probably a good model if you have a lot of tenants on a single > machine (>100). By making it optional we ensure it's not in people's way if > they don't need it. > At the same time, I would like to add a second model that is based on > separate OSGi containers, giving a more natural isolation and a model that > is identical to "normal" OSGi application development. My gut feeling is In the end I think a multi container is the only way to properly address point 1 (and more concerns) as we illustrated before in some conceptual implementation models [2] a while back. > that on average hardware this will still scale to about 100 instances per > computer. Previous art [2] shows about 500 nested containers (with a few small bundles each) on Xmx256M/default permgen with a 32bit java. Obviously, the real measure will depend on the type of multi container model > Before we go into technical details, I'd like your feedback on these ideas > in general. +1 on the goals. grz Bram [0] http://www.amdatu.org/confluence/display/Amdatu/Milestones [1] http://www.amdatu.org/confluence/download/attachments/1606083/Amdatu+Multi-tenancy+-+bramk.pdf?version=1&modificationDate=1291983250783 [2] http://www.mail-archive.com/[email protected]/msg01772.html > Greetings, Marcel > > _______________________________________________ > Amdatu-developers mailing list > [email protected] > http://lists.amdatu.org/mailman/listinfo/amdatu-developers > > _______________________________________________ Amdatu-developers mailing list [email protected] http://lists.amdatu.org/mailman/listinfo/amdatu-developers
