With maxParallel > 1, archiving stores the same WALs multiple times.
It looks like this:
Archive WAL 1,2,3,4
Archive WAL 2,3,4,5
Archive WAL 3,4,5,6
Looks like only first WAL on the list to be archived in parallel is being really acknowledged as archived (file name in pg_wal/archive_status changed to *.done), but in fact, all WALs are successfully stored to S3.
{"level":"info","ts":"2025-04-16T07:54:23.778100685+02:00","msg":"Executing barman-cloud-wal-archive","logging_pod":"testml-01d-1","walName":"/var/lib/postgresql/data/pgdata/pg_wal/0000000100000007000000B3","options":["--endpoint-url","https://osf01189.pzu.pl:9021","--cloud-provider","aws-s3","s3://s3backup/ZUBDTESTS/DEV","testml-01d","/var/lib/postgresql/data/pgdata/pg_wal/0000000100000007000000B3"]}
{"level":"info","ts":"2025-04-16T07:54:23.778188143+02:00","msg":"Executing barman-cloud-wal-archive","logging_pod":"testml-01d-1","walName":"/var/lib/postgresql/data/pgdata/pg_wal/0000000100000007000000B0","options":["--endpoint-url","https://osf01189.pzu.pl:9021","--cloud-provider","aws-s3","s3://s3backup/ZUBDTESTS/DEV","testml-01d","/var/lib/postgresql/data/pgdata/pg_wal/0000000100000007000000B0"]}
{"level":"info","ts":"2025-04-16T07:54:23.778205217+02:00","msg":"Executing barman-cloud-wal-archive","logging_pod":"testml-01d-1","walName":"/var/lib/postgresql/data/pgdata/pg_wal/0000000100000007000000AE","options":["--endpoint-url","https://osf01189.pzu.pl:9021","--cloud-provider","aws-s3","s3://s3backup/ZUBDTESTS/DEV","testml-01d","/var/lib/postgresql/data/pgdata/pg_wal/0000000100000007000000AE"]}
{"level":"info","ts":"2025-04-16T07:54:23.779015379+02:00","msg":"Executing barman-cloud-wal-archive","logging_pod":"testml-01d-1","walName":"/var/lib/postgresql/data/pgdata/pg_wal/0000000100000007000000B1","options":["--endpoint-url","https://osf01189.pzu.pl:9021","--cloud-provider","aws-s3","s3://s3backup/ZUBDTESTS/DEV","testml-01d","/var/lib/postgresql/data/pgdata/pg_wal/0000000100000007000000B1"]}
{"level":"info","ts":"2025-04-16T07:54:23.779264442+02:00","msg":"Executing barman-cloud-wal-archive","logging_pod":"testml-01d-1","walName":"/var/lib/postgresql/data/pgdata/pg_wal/0000000100000007000000B2","options":["--endpoint-url","https://osf01189.pzu.pl:9021","--cloud-provider","aws-s3","s3://s3backup/ZUBDTESTS/DEV","testml-01d","/var/lib/postgresql/data/pgdata/pg_wal/0000000100000007000000B2"]}
{"level":"info","ts":"2025-04-16T07:54:23.779279747+02:00","msg":"Executing barman-cloud-wal-archive","logging_pod":"testml-01d-1","walName":"/var/lib/postgresql/data/pgdata/pg_wal/0000000100000007000000AF","options":["--endpoint-url","https://osf01189.pzu.pl:9021","--cloud-provider","aws-s3","s3://s3backup/ZUBDTESTS/DEV","testml-01d","/var/lib/postgresql/data/pgdata/pg_wal/0000000100000007000000AF"]}
{"level":"info","ts":"2025-04-16T07:54:25.906978929+02:00","msg":"Archived WAL file","logging_pod":"testml-01d-1","walName":"/var/lib/postgresql/data/pgdata/pg_wal/0000000100000007000000B1","startTime":"2025-04-16T07:54:23.779004082+02:00","endTime":"2025-04-16T07:54:25.906906667+02:00","elapsedWalTime":2.127902547}
{"level":"info","ts":"2025-04-16T07:54:25.911192115+02:00","msg":"Archived WAL file","logging_pod":"testml-01d-1","walName":"/var/lib/postgresql/data/pgdata/pg_wal/0000000100000007000000AE","startTime":"2025-04-16T07:54:23.778190846+02:00","endTime":"2025-04-16T07:54:25.91117647+02:00","elapsedWalTime":2.132985614}
{"level":"info","ts":"2025-04-16T07:54:25.91147455+02:00","msg":"Archived WAL file","logging_pod":"testml-01d-1","walName":"/var/lib/postgresql/data/pgdata/pg_wal/0000000100000007000000B2","startTime":"2025-04-16T07:54:23.779247422+02:00","endTime":"2025-04-16T07:54:25.9114261+02:00","elapsedWalTime":2.132178543}
{"level":"info","ts":"2025-04-16T07:54:25.915912703+02:00","msg":"Archived WAL file","logging_pod":"testml-01d-1","walName":"/var/lib/postgresql/data/pgdata/pg_wal/0000000100000007000000AF","startTime":"2025-04-16T07:54:23.779266725+02:00","endTime":"2025-04-16T07:54:25.915864425+02:00","elapsedWalTime":2.136597762}
{"level":"info","ts":"2025-04-16T07:54:25.918102236+02:00","msg":"Archived WAL file","logging_pod":"testml-01d-1","walName":"/var/lib/postgresql/data/pgdata/pg_wal/0000000100000007000000B3","startTime":"2025-04-16T07:54:23.778092287+02:00","endTime":"2025-04-16T07:54:25.918057865+02:00","elapsedWalTime":2.13996565}
{"level":"info","ts":"2025-04-16T07:54:25.94661216+02:00","msg":"Archived WAL file","logging_pod":"testml-01d-1","walName":"/var/lib/postgresql/data/pgdata/pg_wal/0000000100000007000000B0","startTime":"2025-04-16T07:54:23.778176382+02:00","endTime":"2025-04-16T07:54:25.946542198+02:00","elapsedWalTime":2.168365812}
{"level":"info","ts":"2025-04-16T07:54:25.983819819+02:00","msg":"Executing barman-cloud-wal-archive","logging_pod":"testml-01d-1","walName":"/var/lib/postgresql/data/pgdata/pg_wal/0000000100000007000000B3","options":["--endpoint-url","https://osf01189.pzu.pl:9021","--cloud-provider","aws-s3","s3://s3backup/ZUBDTESTS/DEV","testml-01d","/var/lib/postgresql/data/pgdata/pg_wal/0000000100000007000000B3"]}
{"level":"info","ts":"2025-04-16T07:54:25.983866113+02:00","msg":"Executing barman-cloud-wal-archive","logging_pod":"testml-01d-1","walName":"/var/lib/postgresql/data/pgdata/pg_wal/0000000100000007000000B0","options":["--endpoint-url","https://osf01189.pzu.pl:9021","--cloud-provider","aws-s3","s3://s3backup/ZUBDTESTS/DEV","testml-01d","/var/lib/postgresql/data/pgdata/pg_wal/0000000100000007000000B0"]}
{"level":"info","ts":"2025-04-16T07:54:25.983885335+02:00","msg":"Executing barman-cloud-wal-archive","logging_pod":"testml-01d-1","walName":"/var/lib/postgresql/data/pgdata/pg_wal/0000000100000007000000AF","options":["--endpoint-url","https://osf01189.pzu.pl:9021","--cloud-provider","aws-s3","s3://s3backup/ZUBDTESTS/DEV","testml-01d","/var/lib/postgresql/data/pgdata/pg_wal/0000000100000007000000AF"]}
{"level":"info","ts":"2025-04-16T07:54:25.984003004+02:00","msg":"Executing barman-cloud-wal-archive","logging_pod":"testml-01d-1","walName":"/var/lib/postgresql/data/pgdata/pg_wal/0000000100000007000000B1","options":["--endpoint-url","https://osf01189.pzu.pl:9021","--cloud-provider","aws-s3","s3://s3backup/ZUBDTESTS/DEV","testml-01d","/var/lib/postgresql/data/pgdata/pg_wal/0000000100000007000000B1"]}
{"level":"info","ts":"2025-04-16T07:54:25.984100209+02:00","msg":"Executing barman-cloud-wal-archive","logging_pod":"testml-01d-1","walName":"/var/lib/postgresql/data/pgdata/pg_wal/0000000100000007000000B2","options":["--endpoint-url","https://osf01189.pzu.pl:9021","--cloud-provider","aws-s3","s3://s3backup/ZUBDTESTS/DEV","testml-01d","/var/lib/postgresql/data/pgdata/pg_wal/0000000100000007000000B2"]}
{"level":"info","ts":"2025-04-16T07:54:27.739840713+02:00","msg":"Archived WAL file","logging_pod":"testml-01d-1","walName":"/var/lib/postgresql/data/pgdata/pg_wal/0000000100000007000000B1","startTime":"2025-04-16T07:54:25.983985892+02:00","endTime":"2025-04-16T07:54:27.739778547+02:00","elapsedWalTime":1.755792591}
{"level":"info","ts":"2025-04-16T07:54:27.753287671+02:00","msg":"Archived WAL file","logging_pod":"testml-01d-1","walName":"/var/lib/postgresql/data/pgdata/pg_wal/0000000100000007000000AF","startTime":"2025-04-16T07:54:25.983868412+02:00","endTime":"2025-04-16T07:54:27.753269805+02:00","elapsedWalTime":1.769401393}
{"level":"info","ts":"2025-04-16T07:54:27.762278783+02:00","msg":"Archived WAL file","logging_pod":"testml-01d-1","walName":"/var/lib/postgresql/data/pgdata/pg_wal/0000000100000007000000B3","startTime":"2025-04-16T07:54:25.983805658+02:00","endTime":"2025-04-16T07:54:27.762222163+02:00","elapsedWalTime":1.778416538}
{"level":"info","ts":"2025-04-16T07:54:27.764376746+02:00","msg":"Archived WAL file","logging_pod":"testml-01d-1","walName":"/var/lib/postgresql/data/pgdata/pg_wal/0000000100000007000000B0","startTime":"2025-04-16T07:54:25.98384297+02:00","endTime":"2025-04-16T07:54:27.764331456+02:00","elapsedWalTime":1.780488567}
{"level":"info","ts":"2025-04-16T07:54:27.779976864+02:00","msg":"Archived WAL file","logging_pod":"testml-01d-1","walName":"/var/lib/postgresql/data/pgdata/pg_wal/0000000100000007000000B2","startTime":"2025-04-16T07:54:25.984090309+02:00","endTime":"2025-04-16T07:54:27.77991625+02:00","elapsedWalTime":1.795825972}
With maxParallel > 1, archiving stores the same WALs multiple times.
It looks like this:
Archive WAL 1,2,3,4
Archive WAL 2,3,4,5
Archive WAL 3,4,5,6
Looks like only first WAL on the list to be archived in parallel is being really acknowledged as archived (file name in pg_wal/archive_status changed to *.done), but in fact, all WALs are successfully stored to S3.