We are pleased to announce the preview of multi-subnet support for Google Kubernetes Engine (GKE) clusters. This enhancement removes single-subnet limitations, increasing scalability, optimizing resource utilization, and enhancing flexibility of your GKE clusters.
Multi-subnet support for GKE clusters allows you to add additional subnets to an existing GKE cluster, which can then be utilized by new node pools. This functionality is supported for all clusters, using GKE version 1.30.3-gke.1211000 or greater.
Benefits
- Increased scalability: Clusters can now scale beyond the limits of a single subnets primary IP range.
- Optimized resource utilization: IP addresses can be allocated more efficiently across multiple subnets, which reduces IP waste.
- Enhanced flexibility: Adding subnets provides more flexibility in managing IP ranges for pods and services. Subnets can be updated without recreating the cluster so you can easily expand beyond initial cluster configurations.
Use case: Node IP exhaustion
Historically, GKE clusters are created on a single subnet, using its primary IP range. Once all the IPs in the primary range are used, the cluster can no longer add more nodes, and hence cannot expand or autoscale.
The IP exhaustion errors look something like this:
Source Credit: https://cloud.google.com/blog/products/networking/multi-subnet-support-for-gke-clusters-increases-scalability/
