Custom Hostname - Multiple Instances

I have created a workflow that changes the machine name to a custom name.

The workflow creates a machine name by using custom properties from vRA and then verify that the name is not used in vSphere (using getAllVMsMatchingRegexp action) The result is a new, unused Custom name.

It works perfectly for a single VM.

When I deploy multiply VMs the workflow run in parallel and the output for all instances is the same hostname… (the VM have not been created yet)

Any idea how to solve this?

What are my options?

I am using subscription and extensibility, so the output is –

virtualMachineAddOrUpdateProperties.put(‘Name’, machineName);

Thanks!