Multi-cluster communication
- Separate failure domains. Failure of a cluster allows the remaining clusters to function.
- Support for heterogeneous networks. Since clusters can span clouds, VPCs, on-premises data centers, and combinations thereof, Linkerd does not introduce any L3/L4 requirements other than gateway connectivity.
Just as with in-cluster connections, Linkerd’s cross-cluster connections are transparent to the application code. Regardless of whether that communication happens within a cluster, across clusters within a datacenter or VPC, or across the public Internet, Linkerd will establish a connection between clusters that’s encrypted and authenticated on both sides with mTLS.
Linkerd’s control plane contains two multi-cluster components on each cluster: a service mirror and a gateway. The service mirror component watches target clusters for updates to services and mirrors those service updates locally on a source cluster. This provides visibility into the service names on other, target clusters so that applications can address them directly. The multi-cluster gateway component provides a way target clusters to receive requests from source clusters. (This allows Linkerd to support .)
Ready to get started? See the getting started with multi-cluster guide for a walkthrough.
Further reading
- Multi-cluster installation instructions.
- , a blog post explaining some of the design rationale behind Linkerd’s multi-cluster implementation.