RE: Logical replication type- WAL recovery fails and changes the size of wal segment in archivedir

[Meera Nair <mnair@xxxxxxxxxxxxx>]

Hi Ron,

We do have our own solution. We work for Commvault, a data protection company.

We support backup of PostgreSQL in different ways - streaming, snapshot, block level, backup from standby server.

PostgreSQL (commvault.com)

 

Regards,

Meera

 

From: Ron Johnson <ronljohnsonjr@xxxxxxxxx>
Sent: Thursday, June 6, 2024 9:56 PM
To: Laurenz Albe <laurenz.albe@xxxxxxxxxxx>
Cc: Meera Nair <mnair@xxxxxxxxxxxxx>; pgsql-general@xxxxxxxxxxxxxxxxxxxx; Punit Pranesh Koujalgi <pkoujalgi@xxxxxxxxxxxxx>; B Ganesh Kishan <bkishan@xxxxxxxxxxxxx>
Subject: Re: Logical replication type- WAL recovery fails and changes the size of wal segment in archivedir

 

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On Wed, Jun 5, 2024 at 6:26 AM Laurenz Albe <laurenz.albe@xxxxxxxxxxx> wrote:

On Wed, 2024-06-05 at 06:36 +0000, Meera Nair wrote:
> 2024-06-05 11:41:32.369 IST [54369] LOG:  restored log file "00000005000000010000006A" from archive
> 2024-06-05 11:41:33.112 IST [54369] LOG:  restored log file "00000005000000010000006B" from archive
> cp: cannot stat ‘/home/pgsql/wmaster/00000005000000010000006C’: No such file or directory
> 2024-06-05 11:41:33.167 IST [54369] LOG:  redo done at 1/6B000100   
> 2024-06-05 11:41:33.172 IST [54369] FATAL:  archive file "00000005000000010000006B" has wrong size: 0 instead of 16777216
> 2024-06-05 11:41:33.173 IST [54367] LOG:  startup process (PID 54369) exited with exit code 1
> 2024-06-05 11:41:33.173 IST [54367] LOG:  terminating any other active server processes
> 2024-06-05 11:41:33.174 IST [54375] FATAL:  archive command was terminated by signal 3: Quit
> 2024-06-05 11:41:33.174 IST [54375] DETAIL:  The failed archive command was: cp pg_wal/00000005000000010000006B /home/pgsql/wmaster/00000005000000010000006B
> 2024-06-05 11:41:33.175 IST [54367] LOG:  archiver process (PID 54375) exited with exit code 1
> 2024-06-05 11:41:33.177 IST [54367] LOG:  database system is shut down
>  
> Here ‘/home/pgsql/wmaster’ is my archivedir (the folder where WAL segments are restored from)
>  
> Before attempting start, size of
> 00000005000000010000006B file was 16 MB.
> After failing to detect 00000005000000010000006C, there is a FATAL error saying wrong size for 00000005000000010000006B
> Now the size of 00000005000000010000006B is observed as 2 MB. Size of all other WAL segments remain 16 MB.
>  
> -rw------- 1 postgres postgres  2359296 Jun  5 11:34 00000005000000010000006B

That looks like you have "archive_mode = always", and "archive_command" writes
back to the archive.  Don't do that.

 

In fact, don't write your own PITR backup process.  Use something like PgBackRest or BarMan.