"The greatest disadvantage of the two-phase commit protocol is that it is a blocking protocol. If the coordinator fails permanently, some cohorts will never resolve their transactions: After a cohort has sent an *agreement* message to the coordinator, it will block until a *commit* or *rollback* is received." https://en.wikipedia.org/wiki/Two-phase_commit_protocol
That's a heck of a lot of work to share a zip code table... On Friday, March 13, 2015 at 9:19:20 AM UTC-4, Anthony wrote: > > On Friday, March 13, 2015 at 7:13:52 AM UTC-4, Niphlod wrote: >> >> >>> Why would you need a commit()? If everything is happening within a >>> web2py request, any open transactions will be rolled back should either >>> database throw an error, or if the app code itself results in an exception. >>> So, if a record in one database is deleted, but then an exception occurs >>> before the linked record in the other database is deleted, the initial >>> delete gets rolled back. >>> >>> >> Still not convinced. if you don't commit() before you don't know what is >> going wrong, and you must be sure that the only operation going wrong is >> updating the two databases at the same time. >> > > Is the concern that the commit operation of the second transaction will > itself raise an exception (at which point, the first transaction has > already been commited)? Aside from that possibility, wouldn't any error > (within the databases or otherwise) simply result in both transactions > being rolled back? I'm not saying this is as good as having everything in > one database, but if you *have to* have two databases, you have to manage > this via the framework/app code somehow. What else would you suggest? > > Anthony > -- Resources: - http://web2py.com - http://web2py.com/book (Documentation) - http://github.com/web2py/web2py (Source code) - https://code.google.com/p/web2py/issues/list (Report Issues) --- You received this message because you are subscribed to the Google Groups "web2py-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to web2py+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
