Disaster Recovery with stretch cluster

In this case, a single cluster is stretched across two zones with a third zone as the location for the arbiter. This feature is currently intended for deployment in the OpenShift Container Platform on-premises and in the same data center. Consider Metro-DR as a first option for no data loss DR solution deployed over multiple data centers with low latency networks.

Note: The stretch cluster solution is designed for deployments where latencies do not exceed 10 ms maximum round-trip time (RTT) between the zones containing data volumes. For Arbiter nodes follow the latency requirements specified for etcd, see Guidance for Red Hat OpenShift Container Platform Clusters - Deployments Spanning Multiple Sites(Data Centers/Regions). Contact IBM Supportif you are planning to deploy with higher latencies.
To use the stretch cluster
  • You must have a minimum of five nodes across three zones, where two nodes per zone are used for each data-center zone, and one additional zone with one node is used for arbiter zone (the arbiter can be on a master node).
  • All the nodes must be manually labeled with the zone labels prior to cluster creation.
    For example, the zones can be labeled as:
    • topology.kubernetes.io/zone=arbiter (master or worker node)
    • topology.kubernetes.io/zone=datacenter1 (minimum two worker nodes)
    • topology.kubernetes.io/zone=datacenter2 (minimum two worker nodes)

For more information, see Disaster recovery with stretch cluster for Fusion Data Foundation