public inbox for [email protected]
help / color / mirror / Atom feedFrom: Hayato Kuroda (Fujitsu) <[email protected]>
To: 'Antonin Houska' <[email protected]>
To: Amit Kapila <[email protected]>
Cc: Mihail Nikalayeu <[email protected]>
Cc: Andres Freund <[email protected]>
Cc: Alvaro Herrera <[email protected]>
Cc: Srinath Reddy Sadipiralla <[email protected]>
Cc: Matthias van de Meent <[email protected]>
Cc: Pg Hackers <[email protected]>
Cc: Robert Treat <[email protected]>
Subject: RE: Adding REPACK [concurrently]
Date: Tue, 12 May 2026 02:25:47 +0000
Message-ID: <OS9PR01MB12149A37B0647D5D3116600C9F5392@OS9PR01MB12149.jpnprd01.prod.outlook.com> (raw)
In-Reply-To: <70574.1778512672@localhost>
References: <CAA4eK1Jg21ODQ7fS2fvN5W_S5kDRhAP5inj3XMRQaa=s-GbYhw@mail.gmail.com>
<[email protected]>
<cdgw4sbbfcgk6du3iv54r2dgiy4tfywoklbotlmj4irxavdcr3@glxfw5jj277q>
<227677.1775576304@localhost>
<pveffyxhnuurhb44uzqlwo3rkyzorkfh2rot7uwzlf2axhfvbp@7nrs2omysxkc>
<CAA4eK1JhuT5fyTosWDZ+Pgs+j7xEjObTyRMn80uNKgi_ivqHbw@mail.gmail.com>
<CADzfLwWnbKcb3v8sStdgNE=WNc3uUqx5SiS4zftX2UaEfNzG5w@mail.gmail.com>
<85813.1777901089@localhost>
<27869.1777985266@localhost>
<CAA4eK1KC6CGN-N2bUffSign8Sw4q6=8d3L-Xh4t+50GCdQb6zw@mail.gmail.com>
<70574.1778512672@localhost>
Dear Antonin,
FYI, I have also been spending time to reproduce the failure but I have not done yet.
> So far I could observe the situation in WAL, but have no idea how it can
> happen.
Not sure it matches with your situation, but I could reproduce the situation by
using gdb.
0. initialized an instance with wal_level=logical and defined a table.
1. established a connection
2. attached the backend via gdb
3. added a breakpoint in ProcArrayEndTransaction
4. committed a transaction, and it would stop at the breakpoint
5. established another connection
6. ran REPACK CONCURRENTLY
7. detached from the first backend.
8. all commands would finish.
This could allow that COMMIT record exists ahead the RUNNING_XACTS record.
When the backend reaches CommitTransaction()->ProcArrayEndTransaction(), the commit
record has already been serialized, but the transaction is still marked as active
on the proc array. Above workload allowed that repack worker could check in-between.
[1]:
```
rmgr: Transaction len (rec/tot): 46/ 46, tx: 695, lsn: 0/018B89C0, prev 0/018B8980, desc: COMMIT 2026-05-12 11:11:31.588061 JST
rmgr: Standby len (rec/tot): 58/ 58, tx: 0, lsn: 0/018B89F0, prev 0/018B89C0, desc: RUNNING_XACTS nextXid 696 latestCompletedXid 694 oldestRunningXid 695; 1 xacts: 695; dbid: 0
rmgr: Standby len (rec/tot): 58/ 58, tx: 0, lsn: 0/018B8A30, prev 0/018B89F0, desc: RUNNING_XACTS nextXid 696 latestCompletedXid 694 oldestRunningXid 695; 1 xacts: 695; dbid: 5
```
Best regards,
Hayato Kuroda
FUJITSU LIMITED
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], [email protected]
Subject: RE: Adding REPACK [concurrently]
In-Reply-To: <OS9PR01MB12149A37B0647D5D3116600C9F5392@OS9PR01MB12149.jpnprd01.prod.outlook.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