Resource Allocation

To avoid contention and starvation, compute, storage, and network isolation must be applied consistently to the workloads.

The CSP admin can allocate and reserve resources for tenants by using Tenant VDC. Every Tenant VDC is associated with a resource pool across the Resource Pods. The resource settings of the resource pool are managed from VMware Integrated OpenStack. This ensures that every Tenant VDC allocates the resources to which it is entitled, without exceeding the infrastructure resource limits, such as CPU clock cycles, total memory, network bandwidth, and storage.

Resource allocation policies can be applied to the VMs so that they receive a fair share of resources across the infrastructure pool. Each VM configuration is taken from a template that is called a Flavor. Flavor metadata can be used to configure the allocation of CPU (MHz), memory (MB), storage (IOPS), and virtual interfaces (Mbps).

The following boundary parameters can be set. These parameters control the elasticity and priority of the resources that are assigned to the VNF component executing within the VM.

• Reservation: Defines the minimum guarantee provided to each VM when it is launched.

• Limit: Defines the upper boundary. The Limit parameter must be used with caution in a production environment, because it restricts the VM from bursting utilization beyond the configured boundaries.

• Shares: Defines the distribution of resources under contention. The Shares parameter can be used to prioritize certain workloads over others in case of contention. If resources are over-provisioned across VMs and there is resource contention, the VM with high shares gets the proportional resource assignment.

For the control plane workload functions, a high-order elasticity is acceptable and memory can be reserved based on the workload requirement. For the data plane intensive workloads, both CPU and memory must be fully reserved. Storage IO and network throughput reservations must be determined based on the VNF requirements.