Hi communities

I have set cinder backup with these configurations
backup_max_operations = 4
backup_workers = 4

When I create 20 backups simultaneously
According to logs It still creating backups at the same time.

2023-11-07 06:17:42.029 555360 INFO cinder.backup.manager [] Create backup started, backup: <BACKUP-ID> volume: <VOLUME-ID>
2023-11-07 06:17:42.038 555360 INFO cinder.backup.manager [] Call Volume Manager to get_backup_device for Backup(*TRUNCRATED*)
2023-11-07 06:17:44.328 555360 INFO cinder.backup.manager [] Create backup started, backup: <BACKUP-ID> volume: <VOLUME-ID>
2023-11-07 06:17:44.334 555360 INFO cinder.backup.manager [] Call Volume Manager to get_backup_device for Backup(*TRUNCRATED*)
2023-11-07 06:17:46.665 555360 INFO cinder.backup.manager [] Create backup started, backup: <BACKUP-ID> volume: <VOLUME-ID>
2023-11-07 06:17:46.672 555360 INFO cinder.backup.manager [] Call Volume Manager to get_backup_device for Backup(*TRUNCRATED*)
2023-11-07 06:17:49.005 555360 INFO cinder.backup.manager [] Create backup started, backup: <BACKUP-ID> volume: <VOLUME-ID>
2023-11-07 06:17:49.018 555360 INFO cinder.backup.manager [] Call Volume Manager to get_backup_device for Backup(*TRUNCRATED*)
2023-11-07 06:17:51.378 555360 INFO cinder.backup.manager [] Create backup started, backup: <BACKUP-ID> volume: <VOLUME-ID>
2023-11-07 06:17:51.389 555360 INFO cinder.backup.manager [] Call Volume Manager to get_backup_device for Backup(*TRUNCRATED*)
2023-11-07 06:17:54.004 555360 INFO cinder.backup.manager [] Create backup started, backup: <BACKUP-ID> volume: <VOLUME-ID>
2023-11-07 06:17:54.017 555360 INFO cinder.backup.manager [] Call Volume Manager to get_backup_device for Backup(*TRUNCRATED*)
2023-11-07 06:17:56.094 555360 INFO cinder.backup.manager [] Create backup started, backup: <BACKUP-ID> volume: <VOLUME-ID>
2023-11-07 06:17:56.113 555360 INFO cinder.backup.manager [] Call Volume Manager to get_backup_device for Backup(*TRUNCRATED*)
2023-11-07 06:17:58.523 555360 INFO cinder.backup.manager [] Create backup started, backup: <BACKUP-ID> volume: <VOLUME-ID>
2023-11-07 06:17:58.536 555360 INFO cinder.backup.manager [] Call Volume Manager to get_backup_device for Backup(*TRUNCRATED*)
2023-11-07 06:18:01.017 555360 INFO cinder.backup.manager [] Create backup started, backup: <BACKUP-ID> volume: <VOLUME-ID>
2023-11-07 06:18:01.027 555360 INFO cinder.backup.manager [] Call Volume Manager to get_backup_device for Backup(*TRUNCRATED*)
2023-11-07 06:18:03.146 555360 INFO cinder.backup.manager [] Create backup started, backup: <BACKUP-ID> volume: <VOLUME-ID>
2023-11-07 06:18:03.162 555360 INFO cinder.backup.manager [] Call Volume Manager to get_backup_device for Backup(*TRUNCRATED*)
2023-11-07 06:18:05.622 555360 INFO cinder.backup.manager [] Create backup started, backup: <BACKUP-ID> volume: <VOLUME-ID>
2023-11-07 06:18:05.649 555360 INFO cinder.backup.manager [] Call Volume Manager to get_backup_device for Backup(*TRUNCRATED*)
2023-11-07 06:18:07.800 555360 INFO cinder.backup.manager [] Create backup started, backup: <BACKUP-ID> volume: <VOLUME-ID>
2023-11-07 06:18:07.818 555360 INFO cinder.backup.manager [] Call Volume Manager to get_backup_device for Backup(*TRUNCRATED*)
2023-11-07 06:18:10.129 555360 INFO cinder.backup.manager [] Create backup started, backup: <BACKUP-ID> volume: <VOLUME-ID>
2023-11-07 06:18:10.148 555360 INFO cinder.backup.manager [] Call Volume Manager to get_backup_device for Backup(*TRUNCRATED*)
2023-11-07 06:18:12.684 555360 INFO cinder.backup.manager [] Create backup started, backup: <BACKUP-ID> volume: <VOLUME-ID>
2023-11-07 06:18:12.775 555360 INFO cinder.backup.manager [] Call Volume Manager to get_backup_device for Backup(*TRUNCRATED*)
2023-11-07 06:18:16.356 555360 INFO cinder.backup.manager [] Create backup started, backup: <BACKUP-ID> volume: <VOLUME-ID>
2023-11-07 06:18:16.400 555360 INFO cinder.backup.manager [] Call Volume Manager to get_backup_device for Backup(*TRUNCRATED*)
2023-11-07 06:18:17.480 555360 INFO cinder.backup.manager [] Create backup started, backup: <BACKUP-ID> volume: <VOLUME-ID>
2023-11-07 06:18:17.575 555360 INFO cinder.backup.manager [] Call Volume Manager to get_backup_device for Backup(*TRUNCRATED*)
2023-11-07 06:18:20.227 555360 INFO cinder.backup.manager [] Create backup started, backup: <BACKUP-ID> volume: <VOLUME-ID>
2023-11-07 06:18:20.249 555360 INFO cinder.backup.manager [] Call Volume Manager to get_backup_device for Backup(*TRUNCRATED*)
2023-11-07 06:18:22.115 555360 INFO cinder.backup.manager [] Create backup started, backup: <BACKUP-ID> volume: <VOLUME-ID>
2023-11-07 06:18:22.165 555360 INFO cinder.backup.manager [] Call Volume Manager to get_backup_device for Backup(*TRUNCRATED*)
2023-11-07 06:18:24.379 555360 INFO cinder.backup.manager [] Create backup started, backup: <BACKUP-ID> volume: <VOLUME-ID>
2023-11-07 06:18:24.435 555360 INFO cinder.backup.manager [] Call Volume Manager to get_backup_device for Backup(*TRUNCRATED*)
2023-11-07 06:18:27.681 555360 INFO cinder.backup.manager [] Create backup started, backup: <BACKUP-ID> volume: <VOLUME-ID>
2023-11-07 06:18:28.074 555360 INFO cinder.backup.manager [] Call Volume Manager to get_backup_device for Backup(*TRUNCRATED*)
2023-11-07 06:18:29.440 555360 INFO cinder.backup.manager [] Create backup started, backup: <BACKUP-ID> volume: <VOLUME-ID>
2023-11-07 06:18:30.324 555360 INFO cinder.backup.manager [] Call Volume Manager to get_backup_device for Backup(*TRUNCRATED*)
2023-11-07 06:18:31.846 555360 INFO cinder.backup.manager [] Create backup started, backup: <BACKUP-ID> volume: <VOLUME-ID>
2023-11-07 06:18:31.874 555360 INFO cinder.backup.manager [] Call Volume Manager to get_backup_device for Backup(*TRUNCRATED*)

The expected result is creating 4  backups simultaneously
Have anyone face this issue ? or Do I config a wrong configuration ?

Thanks
Pureewat Kaewpoi