Overview
Direct Answer
Spot instances are unused cloud computing capacity that providers offer at discounts typically 70–90% below on-demand rates, with the trade-off that the provider can terminate the instance with minimal notice when capacity is needed elsewhere. This model allows organisations to access compute resources opportunistically rather than maintaining guaranteed availability.
How It Works
Cloud providers maintain spare infrastructure capacity across data centres. When demand for standard reserved or on-demand instances declines, they release this surplus capacity as interruptible compute at auction-like pricing. Customers specify a maximum price they will pay; if the provider's available capacity falls below that threshold, instances are reclaimed, typically with a two-minute termination warning.
Why It Matters
The cost reduction is substantial for non-time-critical workloads, enabling organisations to run larger-scale batch processing, machine learning training, and analytics without proportional budget increases. This elasticity supports innovation and testing in resource-constrained enterprises whilst allowing providers to optimise utilisation of their infrastructure.
Common Applications
Batch data processing, long-running machine learning model training, distributed rendering, genomic sequencing analysis, and retrospective log analysis benefit significantly from spot capacity. Development and testing environments also leverage spot instances to reduce infrastructure costs without affecting production systems.
Key Considerations
Interruption risk makes spot instances unsuitable for stateful, long-running services or time-sensitive workloads unless paired with automatic failover and fault-tolerance mechanisms. Practitioners must architect applications with graceful termination handling and implement checkpointing for iterative workloads.
Cross-References(1)
More in Cloud Computing
Pub/Sub
Architecture PatternsA messaging pattern where publishers send messages to topics and subscribers receive messages from topics of interest.
Event-Driven Architecture
Architecture PatternsAn architecture pattern where the flow of the system is determined by events — significant changes in state.
Cloud Governance
Strategy & EconomicsThe policies, procedures, and tools for managing cloud resource usage, security, compliance, and costs.
Identity and Access Management
Strategy & EconomicsA framework for managing digital identities and controlling user access to resources and systems.
Reserved Instance
Strategy & EconomicsA cloud pricing model where users commit to a specific resource configuration for a term in exchange for discounted rates.
Cloud-Native Development
Service ModelsAn approach to building applications that fully exploit cloud computing advantages including microservices, containers, dynamic orchestration, and continuous delivery.
Multi-Tenancy
Strategy & EconomicsA software architecture where a single instance serves multiple customers, with each tenant's data isolated and invisible to others.
Cloud Security
Strategy & EconomicsThe set of policies, technologies, and controls deployed to protect cloud-based systems, data, and infrastructure.