Currently all log entries will have the request ID of the latest request that was received in the Backup service. So you would receive a request with ID 1 and you would start logging that thread log calls with its ID, but as soon as you receive another request, let's say with ID 2, you will have both request logging with ID 2 instead of each one logging with its own request ID.
Verified on: openstack-cinder-10.0.6-24.el7ost.noarch 1. Created two Cinder volumes. 2. Issued two backup-create commands at the same time. With --debug recorder two unique backup request IDs req-3ab48541-6cf2-4953-8fa6-fbbfa0e6e534 req-cfb7e259-a633-4ff0-91f7-2acd569b3c40 Backup.log references both request IDs. Also note req-3ab.. mentioned again at the end, in between two req-cfb.. 2018-05-09 10:49:33.206 92855 WARNING os_brick.initiator.connectors.iscsi [req-3ab48541-6cf2-4953-8fa6-fbbfa0e6e534 .... 2018-05-09 10:49:34.298 92855 INFO os_brick.initiator.connectors.iscsi [req-cfb7e259-a633-4ff0-91f7-2acd569b3c40 .... 2018-05-09 10:50:06.586 92855 INFO cinder.backup.manager [req-cfb7e259-a633-4ff0-91f7-2acd569b3c40 ... 2018-05-09 10:50:17.047 92855 INFO cinder.backup.manager [req-3ab48541-6cf2-4953-8fa6-fbbfa0e6e534 b3ab85938eda4e0c96074c0e3f95b062 291b5227ce8f429ca52e26c323b95ca6 ..
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHBA-2018:1611