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CONCEPT Cited by 1 source

Reserved vs. shared capacity

Reserved capacity guarantees exclusive resources to a tenant; shared capacity provides a common pool any tenant can burst into when demand exceeds its reservation.

Definition

Most multi-tenant compute platforms offer two resource pools:

  • Reserved — pre-allocated resources dedicated to a specific tenant or subtree. Provides throughput guarantees and isolation. Tradeoff: unused reserved capacity is wasted unless the system supports lending.
  • Shared — a global surplus pool accessible to all tenants. Provides elasticity and higher utilization. Tradeoff: no throughput guarantee under contention.

At Netflix

In CMB, reserved capacity on internal tenants was fair-shared across the subtree; on leaf tenants it was exclusively partitioned. Shared capacity was fair-shared at admission only — once admitted, jobs ran to completion.

With Kueue, the semantics evolved: reserved resources are lent to other Cohort members when idle and reclaimed via preemption when needed (reclaimWithinCohort: Any). This eliminates the waste of idle reservations while preserving guarantees.

(Source: sources/2026-06-22-netflix-how-netflix-simplified-batch-compute-with-kueue)

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