On Fri, Dec 13, 2024 at 2:39 PM vignesh C <vignes...@gmail.com> wrote: > > On Fri, 13 Dec 2024 at 13:01, Shubham Khanna > <khannashubham1...@gmail.com> wrote: > > > > On Fri, Dec 13, 2024 at 12:20 PM Peter Smith <smithpb2...@gmail.com> wrote: > > > > > > Hi Shubham. > > > > > > Here are my review comments for v6-0001. > > > > > > ====== > > > 1. > > > +# Verify that the subtwophase is enabled ('e') in the pg_subscription > > > catalog > > > +$node_s->poll_query_until('postgres', > > > + "SELECT count(1) = 2 FROM pg_subscription WHERE subtwophasestate = > > > 'e';") > > > + or die "Timed out while waiting for subscriber to enable twophase"; > > > + > > > > > > This form of the SQL is probably OK but it's a bit tricky; Probably it > > > should have been explained in the comment about where that count "2" > > > has come from. > > > > > > ~~ > > > > > > I think it was OK as before (v5) to be querying until nothing was NOT > > > 'e'. In other words, until everything was enabled 'e'. > > > SELECT count(1) = 0 FROM pg_subscription WHERE subtwophasestate NOT IN > > > ('e'); > > > > > > ~~ > > > > > > OTOH, to save execution time we really would be satisfied with both > > > 'p' and 'e' states here. (we don't strictly need to wait for the > > > transition from 'p' to 'e' to occur). > > > > > > So, SQL like the one below might be the best: > > > > > > # Verify that all subtwophase states are pending or enabled, > > > # e.g. there are no subscriptions where subtwophase is disabled ('d'). > > > SELECT count(1) = 0 FROM pg_subscription WHERE subtwophasestate IN ('d') > > > > > > > I have fixed the given comment. Since prepared transactions are not > > being used anymore, I have removed it from the test file. > > The attached patch contains the suggested changes. > > Few comments: > 1) Since we are providing --enable-two-phase option now and user can > create subscriptions with two-phase option this warning can be removed > now: > <para> > - <application>pg_createsubscriber</application> sets up logical > - replication with two-phase commit disabled. This means that any > - prepared transactions will be replicated at the time > - of <command>COMMIT PREPARED</command>, without advance preparation. > - Once setup is complete, you can manually drop and re-create the > - subscription(s) with > + If <option>--enable-two-phase</option> is not specified, the > + <application>pg_createsubscriber</application> sets up logical > replication > + with two-phase commit disabled. This means that any prepared > transactions > + will be replicated at the time of <command>COMMIT PREPARED</command>, > + without advance preparation. Once setup is complete, you can manually > drop > + and re-create the subscription(s) with > the <link > linkend="sql-createsubscription-params-with-two-phase"><literal>two_phase</literal></link> > - option enabled. > > 2) Since we are not going to wait till the subscriptions are enabled, > we can use safe_psql instead of poll_query_until, something like: > is($node_s->safe_psql('postgres', > "SELECT count(1) = 0 FROM pg_subscription WHERE subtwophasestate = 'd'"), > 't', 'subscriptions are created with the two-phase option enabled'); > > instead of: > +$node_s->poll_query_until('postgres', > + "SELECT count(1) = 0 FROM pg_subscription WHERE > subtwophasestate IN ('d');" > +); > > 3) This can be removed from the commit message: > Documentation has been updated to reflect the new option, and test cases have > been added to validate various scenarios, including proper validation of the > '--enable-two-phase' option and its combinations with other options. > > 4) Should" two-phase option" be "enable-two-phase option" here: > const char *sub_username; /* subscriber username */ > + bool two_phase; /* two-phase option */ > SimpleStringList database_names; /* list of database names */ >
I have fixed the given comments. The attached patch contains the suggested changes. Thanks and regards, Shubham Khanna.
v8-0001-Add-support-for-two-phase-commit-in-pg_createsubs.patch
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