ISC2 Certified Cloud Security Professional (CCSP) Practice Question

The noisy-neighbor effect occurs when multiple tenants share the same physical CPU resources and one tenant's heavy workload monopolizes the scheduler, increasing latency for other VMs. Enabling CPU affinity-also called processor or vCPU pinning-binds each virtual CPU to a specific physical core (or set of cores). By preventing the hypervisor scheduler from moving those vCPUs to other cores, pinning creates hard boundaries between tenants, reducing cache thrashing and limiting the ability of one VM to disrupt another.

Lowering the CPU overcommit ratio can help but does not prevent one VM from monopolizing its entitled cores during bursts, so contention can still occur. Memory ballooning only reclaims unused guest RAM and has no effect on CPU scheduling. Transparent page sharing addresses memory efficiency, not CPU isolation. Therefore, configuring CPU affinity is the most direct control for mitigating CPU-related noisy-neighbor issues in a multi-tenant compute environment.