multicluster

MultiCluster refers to the practice of managing and coordinating multiple computing clusters as a unified environment to enable workload distribution, policy enforcement, and resilience across clusters.

While the concept is applicable to various cluster types, it is commonly discussed in the context of container orchestration systems such as Kubernetes. Objectives include high availability, disaster recovery, regional compliance, and performance optimization by placing workloads closer to users.

Key concepts include a control plane or federation layer that provisions and synchronizes resources across clusters, cross-cluster service discovery and traffic routing, policy and security enforcement, and observability that aggregates metrics from all clusters.

Architecture may involve a centralized global control plane and per-cluster local control planes, with tooling for syncing deployments, configurations, secrets, and state. Patterns include active-active multi-region deployments, active-passive disaster recovery, and temporary test environments spanning clusters.

Common challenges include network connectivity and latency between clusters, data consistency and synchronizing state, security and identity management across clusters, and policy governance. Tooling must address RBAC, auditability, version drift, and compatibility between cluster versions.

Related technologies and approaches include Kubernetes Federation, multi-cluster service meshes, and cross-cluster ingress. Adoption varies by organization and vendor, with choices around centralized vs decentralized control planes and the level of automation and visibility required.