Cloud Bursting

Definition

Cloud bursting is a hybrid cloud deployment pattern in which an application normally runs in a private data center but automatically "bursts" excess workload into a public cloud during periods of peak demand, then scales back down once demand subsides.

Overview

Cloud bursting is motivated by the mismatch between provisioning for average load versus provisioning for peak load. An organization running its baseline workload on owned, on-premises infrastructure would need to buy and maintain enough capacity to handle its highest expected traffic spikes if it relied solely on that infrastructure, even though that peak capacity sits mostly idle the rest of the time. Cloud bursting instead lets the private infrastructure handle steady-state load, while a public cloud provider supplies temporary, elastic capacity only when demand exceeds what the private environment can handle. Implementing cloud bursting requires an application architecture that can span both environments: workloads must be portable (often containerized or built on infrastructure-as-code so the same deployment can run in either location), and there must be a mechanism — load balancers, orchestration tooling, or autoscaling policies — that detects rising demand and automatically provisions and routes traffic to cloud resources, then decommissions them once demand falls. Networking and data synchronization between the on-premises and cloud environments (often via a VPN or dedicated interconnect) must also be established ahead of time so burst capacity can access necessary data and services. Cloud bursting is most commonly associated with predictable, seasonal, or event-driven spikes: retail traffic during holiday sales, ticketing platforms during on-sale moments, batch analytics jobs that occasionally need far more compute than usual, and media workloads during live events. It is less suited to workloads with constant, unpredictable, or already-cloud-native usage patterns, where running entirely in the cloud (or using cloud-native autoscaling) is often simpler than maintaining a working hybrid burst pipeline. The main tradeoffs are the operational complexity of keeping two environments compatible and synchronized, potential latency or consistency issues when workloads span locations, and the cost of maintaining the interconnect and automation needed to burst reliably. When done well, cloud bursting gives organizations the cost efficiency of owned infrastructure for steady-state load with the elasticity of the cloud for peaks, without needing to over-provision on-premises hardware for rare spikes.

Key Concepts

• Runs baseline workload on private/on-premises infrastructure
• Automatically shifts excess demand to a public cloud during traffic spikes
• Requires portable, often containerized workloads deployable to either environment
• Relies on automated detection of demand thresholds to trigger bursting
• Needs reliable, low-latency connectivity between on-premises and cloud environments
• Avoids over-provisioning private infrastructure for rare peak-demand events
• Best suited to predictable or event-driven traffic spikes rather than constant variability
• Scales cloud capacity back down automatically once demand subsides

Use Cases

Frequently Asked Questions

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