竞价 vs 预留 vs 按需
根据负载的可中断性与稳定性匹配计费模式。
摘要与快速解答
主流厂商通过三种镜头出售同样的算力：按需弹性、竞价/抢占拍卖与预留承诺。选错镜头是最常见的云账单错误之一。
审阅于
2026-08-22
On-demand: the default you pay a premium for
On-demand is billed per second or hour with zero commitment. It is the right price for spiky, stateful, or hard-to-replicate workloads, and the wrong price for anything that runs 24/7 for months.
Spot: 60-90% off with an eviction notice
Spot instances are excess capacity sold at deep discounts with a short termination warning (30 seconds to 2 minutes depending on provider). They shine for batch jobs, CI runners, rendering, and fault-tolerant worker pools that checkpoint state externally.
Reserved and savings plans: commit to save
One-year and three-year commitments discount steady-state compute substantially on hyperscalers. Commit only after usage has been stable for several months, and prefer convertible terms if your instance mix may change.
A simple decision rule
Runs occasionally or must never be interrupted: on-demand. Interruptible and parallelizable: spot. Runs 24/7 with predictable size: reserved. Re-run this analysis every quarter as workloads change.
核心结论
- Spot discounts range from 60% to 90% across AWS, Azure, GCP, and Alibaba.
- Reserved commitments reward predictable steady-state workloads.
- Match the pricing model to workload interruptibility, not to habit.
浏览相关云定价指南
对比不同地域、云厂商、硬件规格及工作负载架构。