Hybrid Cloud Bursting Platform

Overview

This architecture keeps baseline workloads in an on-premises data center and bursts excess demand to public cloud capacity when load spikes. Use it when you have existing on-prem investment, data-residency constraints, or predictable base load but occasional peaks that would be expensive to provision for locally. Cloud bursting lets you pay for elastic capacity only when you need it while preserving on-prem control.

Kubernetes provides a consistent runtime on both sides so workloads move without rewriting.

Components

• On-prem Kubernetes: Runs steady-state workloads on owned hardware.
• Cloud Kubernetes: Provides elastic capacity that scales up during peaks.
• VPN or interconnect gateway: Secure, low-latency link between on-prem and cloud.
• Object storage: Shared artifact and data layer accessible from both environments.
• Kafka: Event backbone replicated across sites to coordinate work.
• Prometheus: Unified metrics that trigger burst decisions.
• Terraform: Provisions cloud capacity on demand and tears it down.

Data Flow

Under normal load, requests and jobs run entirely on-prem. When Prometheus detects sustained pressure, queue depth, CPU saturation, or pending pods, automation provisions cloud Kubernetes capacity via Terraform and schedules overflow workloads there. Both clusters consume from the same Kafka topics and read shared data from object storage over the secure link. As demand subsides, cloud capacity drains and is destroyed. Stateless workloads are the primary burst candidates; stateful systems stay anchored on-prem.

Scaling and Resilience

The on-prem cluster handles baseline with fixed capacity; the cloud cluster provides elasticity beyond that. Scaling decisions key off shared metrics, and idempotent, stateless jobs make placement flexible. The same architecture supports disaster recovery: if the on-prem site fails, workloads can run entirely in the cloud. Careful data-locality design minimizes cross-site traffic, which is the main latency and cost driver.

Security

The interconnect is encrypted, and both clusters federate identity with least-privilege access. Network policies and segmentation prevent cloud workloads from over-reaching into on-prem systems. Data crossing the link is encrypted in transit, and residency rules dictate which data may leave the premises. Image signing and admission control apply uniformly so only trusted workloads run in either environment.

Trade-offs and Alternatives

Hybrid bursting preserves on-prem investment and meets residency needs while adding elasticity, but it is operationally complex: you run two platforms, manage a reliable interconnect, and must keep data placement disciplined to avoid latency and egress costs. Network latency limits which workloads can burst. A full cloud migration removes the complexity but abandons on-prem investment and may conflict with residency rules. Choose hybrid bursting when you must keep an on-prem footprint yet need cloud elasticity for peaks or disaster recovery.