HPE Storage requesting a backport of below patch [1] into RHOSP 18.x.
The patch has merged to OpenStack community's Gazpacho branch.

[1] Handling session leak and multithreading issues
https://review.opendev.org/c/openstack/cinder/+/976596

This will help them to fix two issues:
1. Failures are seen when bulk VM creation is done from Horizon UI.
Failures appear linked to the concurrency of incoming requests.
2. Session leak is seen while logout/session cleanup, with concurrent requests.

Version-Release number of selected component (if applicable):
18.x

It is hot customer fix which is currently blocking customer.

So submitting ticket with Severity as "Critical".

Request RH team for quick response please.