On 3/22/21 4:56 PM, Drouvot, Bertrand wrote:
On 3/22/21 3:57 PM, Drouvot, Bertrand wrote:
On 3/22/21 3:10 PM, Fabrízio de Royes Mello wrote:
On Thu, Mar 18, 2021 at 5:34 AM Drouvot, Bertrand <
bdrouvot@amazon.com> wrote:
>
> Thanks!
>
> Just made minor changes to make it compiling again on current master (mainly had to take care of ResolveRecoveryConflictWithSnapshotFullXid() that has been introduced in e5d8a99903).
>
> Please find enclosed the new patch version that currently passes "make check" and the 2 associated TAP tests.
>
Unfortunately it still not applying to the current master:
$ git am ~/Downloads/v10-000*.patch
Applying: Allow logical decoding on standby.
Applying: Add info in WAL records in preparation for logical slot conflict handling.
error: patch failed: src/backend/access/nbtree/nbtpage.c:32
error: src/backend/access/nbtree/nbtpage.c: patch does not apply
Patch failed at 0002 Add info in WAL records in preparation for logical slot conflict handling.
hint: Use 'git am --show-current-patch' to see the failed patch
When you have resolved this problem, run "git am --continue".
If you prefer to skip this patch, run "git am --skip" instead.
To restore the original branch and stop patching, run "git am --abort".
oh Indeed, it's moving so fast!
Let me rebase it (It was already my plan to do so as I have observed during the week end that the v7-0003-Handle-logical-slot-conflicts-on-standby.patch introduced incorrect changes (that should not be there at all in ReplicationSlotReserveWal()) that have been kept in v8, v9 and v10.
please find enclosed the rebase version, that also contains the fix for ReplicationSlotReserveWal() mentioned above.
Going back to looking at the whole thread.
I have one remark regarding the conflicts:
The logical slots are dropped if a conflict is detected.
But, if the slot is not active before being dropped (say wal_level is changed to < logical on master and a logical slot is not active on the standby) then its corresponding pg_stat_database_conflicts.confl_logicalslot is not incremented (as it would be incremented "only" during the cancel of an "active" backend).
I think, it should be incremented in all the cases (active or not), what do you think?
I updated the patch to handle this scenario (see the new pgstat_send_droplogicalslot() in v12-0003-Handle-logical-slot-conflicts-on-standby.patch).
I also added more tests in 023_standby_logical_decoding_conflicts.pl to verify that pg_stat_database_conflicts.confl_logicalslot is updated as expected (see check_confl_logicalslot() in v12-0004-New-TAP-test-for-logical-decoding-on-standby.patch).
Except this remark and the associated changes, then it looks good to me.
Bertrand
