Compute Quota

Quota definition model

At a high level, each quota can include:

• a CPU guarantee, representing a baseline amount of CPU capacity
• a CPU maximum limit, representing the upper CPU boundary
• a memory guarantee, representing a baseline memory entitlement
• a memory maximum limit, representing the upper memory boundary
• a vCPU and memory power-on limit

Each virtual machine gets assigned to a compute quota. The system watches the VMs in that quota, checks their current and expected demand, and sets CPU and memory controls for each VM to keep total usage within the set limits.

Because it is flexible, VMease can handle many different situations. Enterprise IT teams can set quotas for departments, environments, or application tiers. Cloud and managed service providers can match quota policies to tenant plans, commercial tiers, reseller setups, or internal capacity needs.

Closed-loop enforcement architecture

Compute Quota Enforcement works all the time within the VMease control plane. The enforcement service keeps an eye on the current infrastructure, active VMs, quota settings, and live VM demand data. It checks if workloads stay within their quotas and updates limits when needed.

At a high level, each enforcement cycle includes the following activities:

1. Load active compute quota definitions.
2. Identify running VMs assigned to each quota.
3. Read current CPU, memory and host telemetry.
4. Calculate effective quota limits, including inherited limits where applicable.
5. Estimate VM-level demand.
6. Allocate CPU and memory targets within quota boundaries.
7. Apply changes at the hypervisor layer where required.
8. Publish metrics for monitoring, capacity planning and operational review.

This is not just a one-time check. The system runs all the time. As workloads change, demand shifts, or resources get tight, VMease keeps adjusting controls to make sure everything follows the set policies.

Quota scope, priority and conflict resolution

Modern multi-tenant platforms need to support delegated control. A parent organisation, reseller or account may have an overall capacity envelope, while child accounts or workload groups may have their own quota policies beneath it.

VMease resolves this using quota-aware limit calculation. A quota can have configured limits, but those limits are also evaluated against the broader account hierarchy and the guarantees already assigned to related scopes.

This method helps avoid a common problem in capacity management. Individual limits might seem fine on their own, but together they could go beyond what the parent account or cluster can handle.

VMease therefore calculates an effective enforcement limit. In simple terms, the effective limit is the lower of:

• the limit configured for the quota;
• the limit that can be safely inherited from the parent scope once sibling guarantees have been considered.

With this approach, administrators can set flexible quota policies, and VMease still protects the whole platform. A misconfigured child quota cannot quietly use resources that have already been set aside for others.

CPU enforcement

VMease enforces CPU limits based on actual demand rather than the VM's static settings.

A VM's demand is derived from two broad signals:

• how much CPU it is using now;
• how much additional CPU it appears to want but cannot currently obtain.

A VM that is being throttled might not appear to have high CPU usage because it is waiting for CPU time. That is why VMease also checks CPU pressure. This helps distinguish an idle VM from a busy one that is limited.

After estimating demand, VMease assigns CPU within the quota limits. The process is built to be fair, stable, and realistic:

• busy VMs receive a larger share than idle VMs;
• low-demand VMs retain enough CPU to remain responsive;
• No VM is allocated more CPU than its vCPU configuration and the host capacity can use;
• Unused capacity can be redistributed to workloads that still have unmet demand.
• Final CPU limits are applied at the infrastructure layer.

The goal is not to make every VM the same. Instead, it is to make sure CPU is given out based on real demand, while still following the assigned quota for each account, tenant, or workload.

Memory enforcement

Memory enforcement is done carefully because memory pressure can affect guest operating systems and applications more than CPU limits do.

VMease evaluates memory demand and usage across the VMs assigned to a quota, then determines whether memory limits are required. Depending on the enforcement policy and current demand, VMs may either retain their full configured memory or receive a controlled memory limit.

When memory capping is required, VMease sets limits on the host and can use QEMU ballooning to notify the guest operating system. This allows the guest OS to try to reclaim memory itself, rather than just experiencing pressure from the hypervisor.

If a VM does not support ballooning well, memory limits can still be set at the host level, but the guest might not notice the limit as much. That is why having good guest tools and balloon support is important for smooth operation.

Operational outcomes

VMease Compute Quota Enforcement turns shared infrastructure into a controlled, measurable, and practical platform for business.

For enterprise IT teams, it supports internal service levels, departmental allocation, environment separation and operational governance.

For cloud and managed service providers, it supports quota-based plans, tenant fairness, reseller delegation, noisy neighbour protection, and clearer capacity monetisation.

For infrastructure operators, it offers a reliable way to match technical actions with policy goals. Quotas are not just database settings or front-end limits; they are always checked and enforced based on how virtual machines actually behave.

The result is a platform that safely shares infrastructure across many customers, departments, and workloads, while maintaining steady performance and operational control.