On Sun, Jan 18, 2009 at 1:37 PM, Rafal Rusin <[email protected]> wrote:
> Hello, > > recently I added feature request: > https://issues.apache.org/jira/browse/ODE-483 > > It's about adding save/load process instances to/from XML in management > API. > I'd like to hear from you, what's the best solution from your (user's) > perspective. > This is a pretty hard problem. Saving and reloading the instance state is the easy part, migrating it to a new definition is where it gets hairy. Generally speaking, automagically migrating any process definition to a any new one is impossible, too many cases are undecidable. So whichever tool gets used to do that migration will need human input to know what to do in all but simple cases (which might already be interesting). The question then becomes how to describe a transformation from one process definition to another. With a relational database you would use SQL to alter the schema and update data. There's no equivalent for processes. I'm not aware of much literature directly in that field although Tammo may be able to point you to some papers. But there's extensive literature covering graph and tree (which BPEL mostly is) rewriting. For example many language parsing libraries support the rewriting of an AST to another using something close to BNF syntax. So it's a fun project :) Matthieu > > Regards, > -- > Rafał Rusin > www.mimuw.edu.pl/~rrusin <http://www.mimuw.edu.pl/%7Errusin> >
