[neutron] Performance impact for attaching Security Group with more number of rules

Hi,

We have an OpenStack Environment with 5000+ VMs running currently. I want to apply some common Security Group to all my running VMs.

- Common Security Group (SEC_GRP_COMMON) has around 700 rules. - This Security Group (SEC_GRP_COMMON) has been shared to all the OpenStack Projects using Role-Based Access Control (RBAC). - Wanted to apply this Security Group (SEC_GRP_COMMON) to all the running VMs in the Cloud

*Question 1*: With the above scenario, what will happen if I attach this Security Group(with 700+ rules) to all the 5000+ VMs? Will there be any performance issue/impact for the same (CPU utilization, Memory etc. in the Compute Server or Performance issues in application running in the VMs)

*Question 2*: Is there any recommendations or benchmark data for maximum number of rules in the Security Group in OpenStack cloud?

Thanks,

Dhana