On Oct 1, 2010, at 9:40 AM, James wrote: > Hi all, > i'm using SQLAlchemy in a TG2 web app which has long-running jobs > kicked off by user POSTs. > > I'm planning on writing the pending jobs to the DB, then kick off a > threading.Thread at the end of the web app method to actually do the > work. > > Question - I'll need to pass the job description (a SA object) to the > child thread; but to use the description, I need to detach it from the > old TG2 thread's SA session, and reattach it to the child thread's SA > session, right? > > How best to do that? I don't see a way of getting the current session > from a live SA object...
If you're writing jobs to the DB anyway, why not use a different process to handle the jobs, and have it poll the jobs table, instead of passing directly ? That's how I'm currently doing it. The job runner then forks off additional procs to run N number of jobs simultaneously with multiprocessing. You at least get true concurrency that way. Otherwise, the general paradigm to pass state between threads uses merge(), it leaves the original unaffected. obj = Session.query(...).first() start_new_thread(obj) # in the thread's method: def start_my_thing(obj): obj = Session.merge(obj) -- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en.
