Re: Allow pg_archivecleanup to remove backup history files

On Tue, May 9, 2023 at 7:03 PM torikoshia <torikoshia(at)oss(dot)nttdata(dot)com> wrote:
>
> Attached a patch with documentation and regression tests.

Thanks. I think pg_archivecleanup cleaning up history files makes it a
complete feature as there's no need to write custom code/scripts over
and above what pg_archivecleanup provides. It will help those who are
using pg_archivecleanup for cleaning up older WAL files, say from
their archive location.

Just curious to know the driving point behind this proposal - is
pg_archivecleanup deployed in production that was unable to clean up
the history files and there were many such history files left? It will
help us know how pg_archivecleanup is being used.

I'm wondering if making -x generic with '-x' '.backup', is simpler
than adding another option?

Comments on the patch:
1. Why just only the backup history files? Why not remove the timeline
history files too? Is it because there may not be as many tli switches
happening as backups?
2.+sub remove_backuphistoryfile_run_check
+{
Why to invent a new function when run_check() can be made generic with
few arguments passed? For instance, run_check() can receive
pg_archivecleanup command args, what to use for create_files(), in the
error condition if the pg_archivecleanup command args contain 'b',
then use a different message "$test_name: first older WAL file was
cleaned up" or "$test_name: first .backup file was cleaned up".
Otherwise, just modify the messages to be:
"$test_name: first older file %s was cleaned up", $files[0]);
"$test_name: second older file %s was cleaned up", $files[1]);
"$test_name: restart file %s was not cleaned up", $files[2]);
"$test_name: newer file %s was not cleaned up", $files[3]);
"$test_name: unrelated file %s was not cleaned up", $files[4]);

--
Bharath Rupireddy
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com