On Tue, Aug 12, 2025 at 4:37 AM px shi <spxlyy...@gmail.com> wrote:
> Bog-standard PgBackRest retains all WAL files required for a full backup >> set and its associated differential/incremental backups. > > Yes, WAL files are continuous under normal circumstances. However, if the > primary node crashes under high load, the archived WAL logs on S3 may be > discontinuous. > 1) PG does not purge WAL files that are needed for immediate crash recovery. 2) PgBackRest can archive (compressed and encrypted) WAL files to S3. https://pgbackrest.org/user-guide-rhel.html#s3-support > > Ron Johnson <ronljohnso...@gmail.com> 于2025年8月9日周六 02:45写道： > >> On Fri, Aug 8, 2025 at 2:26 PM Greg Sabino Mullane <htamf...@gmail.com> >> wrote: >> >>> There is a scenario: the current timeline of the PostgreSQL primary node >>>> is 1, and the latest WAL file is 100. The standby node has also received up >>>> to WAL file 100. However, the latest WAL file archived is only file 80. If >>>> the primary node crashes at this point and the standby is promoted to the >>>> new primary, archiving will resume from file 100 on timeline 2. As a >>>> result, WAL files from 81 to 100 on timeline 1 will be missing from the >>>> archive. >>>> Is there a good solution to prevent this situation? >>>> >>> >>> I'm still not clear on what the problem here is, other than your >>> archiving not keeping up. The best solution to that is: >>> >>> >>> https://pgbackrest.org/1/configuration.html#section-archive/option-archive-async >>> >>> Yes, you would lost some ability for easy PITR for 80-100, but could >>> still be done by resurrecting your crashed primary, or carefully grabbing >>> from the replica before they get recycled. You can set archive_mode=always >>> on the replicas to help with this. >>> >> >> Bog-standard PgBackRest retains all WAL files required for a full backup >> set and its associated differential/incremental backups, no? I've >> certainly done more than one --type=time --target="${RestoreUntil}" restore >> without giving a second thought to timelines or whether the WAL exists. >> >> Maybe I've just ignored the problem, since it (seemingly) does everything >> for PITR backups. >> > -- Death to <Redacted>, and butter sauce. Don't boil me, I'm still alive. <Redacted> lobster!
