Slice creation with more than 1 VM fails as Openstack Security Group List API when run in parallel returns INTERNAL_SERVER_ERROR

Slice creation with 2 VMs triggers the code for Openstack Project creation in parallel from two instances. Start Project creation involves

• creating project, user, key pair, security group rules
  In this process, for VM2, security group list seems to be consistently failing in handler-vm.log. Since, Security Group cannot be found, VM creation does not proceed. I'll try and see if adding more retries would help, it is currently trying 3 times.

Snapshot of the logs:

2019-07-30 19:30:41,019 - 25781 - WARNING - openstack security group rule list command with non-zero rtncode tenant-1-VD7LLGeoxC: ['openstack', 'security', 'group', 'list', '--project', 'tenant-1-VD7LLGeoxC', '-f', 'json', '-c', 'ID'], rtncode: 1, data_stdout: HttpException: 500: Server Error for url: http://10.100.0.10:9696/v2.0/security-groups?tenant_id=tenant-1-VD7LLGeoxC, Request Failed: internal server error while processing your request.
, data_stderr: None

Solution:
Moved the code for Project creation and deletion in an atomic sequence thus preventing parallel execution of Openstack APIs