Re: [PATCH] Preserve replication origin OIDs in pg_upgrade

public inbox for [email protected]  
help / color / mirror / Atom feed

From: Nisha Moond <[email protected]>
To: Ajin Cherian <[email protected]>
Cc: Shlok Kyal <[email protected]>
Cc: shveta malik <[email protected]>
Cc: Zsolt Parragi <[email protected]>
Cc: vignesh C <[email protected]>
Cc: Hayato Kuroda (Fujitsu) <[email protected]>
Cc: PostgreSQL Hackers <[email protected]>
Cc: shveta malik <[email protected]>
Subject: Re: [PATCH] Preserve replication origin OIDs in pg_upgrade
Date: Wed, 17 Jun 2026 17:12:22 +0530
Message-ID: <CABdArM6fz2w=woUmgPOi4arpNG3BdeYiKMrJ4GwUPgUc+d1nVQ@mail.gmail.com> (raw)
In-Reply-To: <CABdArM6pPWN8yKKHH3ofzCfSjCqBwrWnPbELK2ogAUEQF7WmWw@mail.gmail.com>
References: <CAFPTHDa5aP8ixTZBygGAe48E1N=DvuPzcXikw7bNKixLMN3pVg@mail.gmail.com>
	<OS9PR01MB12149E188221BED862E4BE9E0F5342@OS9PR01MB12149.jpnprd01.prod.outlook.com>
	<CALDaNm2-uwpbJ8fnrssp+hORvOutsqRoZAsa05xVVzXe5Bt3bw@mail.gmail.com>
	<CAFPTHDaNLRqPAda1RUDVfSDH7eLTaONv0UEmc9H5sdMW1Li2Bg@mail.gmail.com>
	<CAN4CZFOb3urMsLPsEyVrYR7-7yA+BC5kDgQQd0nAQ8xj2zyRcA@mail.gmail.com>
	<CAFPTHDYqpuZ6o2-HuCJDYqJ7GY3+zV+Xo-gT7PAgi4Bkz+oTxw@mail.gmail.com>
	<CAN4CZFN4oLdxLwUXHUPV-5mFmK+4dcnppP00fV3i4qmMYCAkGA@mail.gmail.com>
	<CAFPTHDbBiTfjYkQwYTNA2a4LRp8Sp7_zB59fmV0R7977ztxgmg@mail.gmail.com>
	<CAFPTHDaftSwzGTGbFEw8rwDBsub0XqcDm1wxQcquj-Y3PC2qrg@mail.gmail.com>
	<CANhcyEVercsNbgC5CTkMNzh_w_Jv1uK7RQg9vEvAeNQhoBHCKQ@mail.gmail.com>
	<CAJpy0uAXynzWr4w_9GkJC3i=LL9WsRCZYVWAV0PgKmgs8riWzg@mail.gmail.com>
	<CAFPTHDavPyxsWjK0cRO3yOaP4u8FGYrOJuXJB-4wzneAY3H3Ug@mail.gmail.com>
	<CANhcyEVFSutXXdt_0XMCD37NE7Yd7ROdDVEE06D8YVyPNEBFHg@mail.gmail.com>
	<CANhcyEVd7eDKGtsrUqwZO5McTG4dsJ+X8OxO31Xgu6sWmo--hw@mail.gmail.com>
	<CAFPTHDbyVt_ggdi+rOP4=jBmgU=DDgYWuLxc4oQ6ux-T0H-ZBg@mail.gmail.com>
	<CABdArM6pPWN8yKKHH3ofzCfSjCqBwrWnPbELK2ogAUEQF7WmWw@mail.gmail.com>

On Wed, Jun 17, 2026 at 4:29 PM Nisha Moond <[email protected]> wrote:
>
> On Wed, Jun 17, 2026 at 2:49 PM Ajin Cherian <[email protected]> wrote:
> >
> > I have addressed the comments in v8 (attached). I've also now taken
> > out the check for PG17 on old cluster and now all clusters which have
> > replication origins are migrated.
>
> Hi Ajin, Thanks for the patches.
> I have started reviewing the patches. Please find a few initial
> comments below (from v7 review, still applicable to v8):

Please find a couple more comments for the v8-002 patch:

4) I was able to build successfully without all three new header
inclusions below, so we may not need them.
--- a/src/backend/utils/adt/pg_upgrade_support.c
+++ b/src/backend/utils/adt/pg_upgrade_support.c
@@ -11,6 +11,7 @@
+#include "access/genam.h"
...
+#include "utils/fmgroids.h"
...
+#include "utils/snapmgr.h"
~~~

5) Race condition in origin.c: replorigin_create()
- heap_freetuple(tuple);
+ table_close(rel, ExclusiveLock);
+
+ replorigin_create_with_id(roident, roname, InvalidXLogRecPtr);
+

Due to the above refactoring, CREATE SUBSCRIPTION can now fail because
of a race between two concurrent CREATE SUBSCRIPTION commands:

postgres=# create subscription sub2 connection 'dbname=postgres
host=localhost port=7733' publication pub1;
ERROR:  replication origin with ID 2 already exists

I think this happens because the table lock is released, allowing
another session to create a pg_origin with the next available roident,
which replorigin_create_with_id() later attempts to use.

Would it make sense to call replorigin_create_with_id() before
table_close() so the lock is still held? I tested this and it works,
though I'm not fully sure whether self-locking could be a concern
here, since replorigin_create_with_id() again acquires a
RowExclusiveLock on the same table.
~~~

--
Thanks,
Nisha

view thread (45+ messages)  latest in thread

reply

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Reply to all the recipients using the --to and --cc options:
  reply via email

  To: [email protected]
  Cc: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected]
  Subject: Re: [PATCH] Preserve replication origin OIDs in pg_upgrade
  In-Reply-To: <CABdArM6fz2w=woUmgPOi4arpNG3BdeYiKMrJ4GwUPgUc+d1nVQ@mail.gmail.com>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox