While trying to launch several VMs using heat templates on RHEL OpenStack Liberty only 2 out of 8 launched. Rest failed because cinder volumes could not be created.
heat stack status was CREATE_FAILED and cinder volume status was error
HTTPInternalServerError: HTTPInternalServerError (HTTP 500)
Unable to get internal tenant context: Missing required config parameters.
Unable to get Cinder internal context, will not use image-volume cache
For a brief moment there was some log on a console related to haproxy failure
While checking the services I noticed that both haproxy and swift-proxy are not running so just decided to restart them
systemctl restart haproxy.service
systemctl start openstack-swift-proxy.service
After that I could again create cinder volumes via heat templates. So be careful – create VMs from templates with cinder one by one.