On Mon, May 3, 2021 at 5:25 AM Masahiko Sawada <sawada.m...@gmail.com> wrote:
> On Sun, May 2, 2021 at 1:23 AM Zhihong Yu <z...@yugabyte.com> wrote: > > > > > > > > On Fri, Apr 30, 2021 at 9:09 PM Masahiko Sawada <sawada.m...@gmail.com> > wrote: > >> > >> On Wed, Mar 17, 2021 at 6:03 PM Zhihong Yu <z...@yugabyte.com> wrote: > >> > > >> > Hi, > >> > For v35-0007-Prepare-foreign-transactions-at-commit-time.patch : > >> > >> Thank you for reviewing the patch! > >> > >> > > >> > With this commit, the foreign server modified within the transaction > marked as 'modified'. > >> > > >> > transaction marked -> transaction is marked > >> > >> Will fix. > >> > >> > > >> > +#define IsForeignTwophaseCommitRequested() \ > >> > + (foreign_twophase_commit > FOREIGN_TWOPHASE_COMMIT_DISABLED) > >> > > >> > Since the other enum is FOREIGN_TWOPHASE_COMMIT_REQUIRED, I think the > macro should be named: IsForeignTwophaseCommitRequired. > >> > >> But even if foreign_twophase_commit is > >> FOREIGN_TWOPHASE_COMMIT_REQUIRED, the two-phase commit is not used if > >> there is only one modified server, right? It seems the name > >> IsForeignTwophaseCommitRequested is fine. > >> > >> > > >> > +static bool > >> > +checkForeignTwophaseCommitRequired(bool local_modified) > >> > > >> > + if (!ServerSupportTwophaseCommit(fdw_part)) > >> > + have_no_twophase = true; > >> > ... > >> > + if (have_no_twophase) > >> > + ereport(ERROR, > >> > > >> > It seems the error case should be reported within the loop. This way, > we don't need to iterate the other participant(s). > >> > Accordingly, nserverswritten should be incremented for local server > prior to the loop. The condition in the loop would become if > (!ServerSupportTwophaseCommit(fdw_part) && nserverswritten > 1). > >> > have_no_twophase is no longer needed. > >> > >> Hmm, I think If we process one 2pc-non-capable server first and then > >> process another one 2pc-capable server, we should raise an error but > >> cannot detect that. > > > > > > Then the check would stay as what you have in the patch: > > > > if (!ServerSupportTwophaseCommit(fdw_part)) > > > > When the non-2pc-capable server is encountered, we would report the > error in place (following the ServerSupportTwophaseCommit check) and come > out of the loop. > > have_no_twophase can be dropped. > > But if we processed only one non-2pc-capable server, we would raise an > error but should not in that case. > > On second thought, I think we can track how many servers are modified > or not capable of 2PC during registration and unr-egistration. Then we > can consider both 2PC is required and there is non-2pc-capable server > is involved without looking through all participants. Thoughts? > That is something worth trying. Thanks > > Regards, > > -- > Masahiko Sawada > EDB: https://www.enterprisedb.com/ >
