There are patched that change number of threads of keystone to 1 :
https://review.openstack.org/#/c/381032/ https://review.openstack.org/#/c/381034/
There are patched that change number of threads of keystone to 1 :
https:/ /review. openstack. org/#/c/ 381032/ /review. openstack. org/#/c/ 381034/
https:/