Cassandra K8s case studies

Cassandra K8s · Put your knowledge to work in context.

The Cassandra K8s exam validates the practical skills needed to run Apache Cassandra on Kubernetes using an operator-based deployment model. It is aimed at platform engineers, SREs, and database administrators who already understand containers and want to prove they can operate a distributed database safely on a dynamic scheduler. The Cassandra K8s case studies are 5 cases and about 3,558 words.

Zone-Bound PVCs Leave Two Rack Pods Pending After a Node-Pool Refresh

Your team runs a six-node CassandraDatacenter (dc1) on EKS: three racks r1, r2, r3, two nodes per rack, NetworkTopologyStrategy RF=3 for the production keyspace. Each rack is pinned with nodeAffinity to one zone (us-east-1a/b/c), and each pod's PVC is a 2 TiB gp3 volume bound immediately.

724 words, about 4 min 2

Combined Upgrade, Heap Change, and Scale-Out in a 90-Minute Window

Your CassandraDatacenter has 9 nodes across 3 racks (3 per rack), RF=3 NetworkTopologyStrategy for the main keyspace, and 16 vnodes per node. The platform is on Cassandra 4.0 and the operator supports 4.1.

734 words, about 4 min 3

TLS Rollout Breaks Internode Joins and External Driver Topology Refresh

After a security review, you enable TLS for internode and client-to-node traffic on a 6-node cluster (3 racks, RF=3). cert-manager issues one certificate per pod from an internal CA, but the CSR template only includes DNS SANs for .cassandra.svc.cluster.local ; the pods' broadcast address values are pod IPs.

696 words, about 3 min 4

Table-Level Restore From Medusa Into a Smaller Cluster in Another Region

Medusa runs nightly full backups and 6-hourly incrementals to S3 for a 12-node, 3-rack cluster with RF=3 and 4 TB per node. At 14:05 an engineer runs a migration that drops and recreates the orders table with a changed primary key; the old data is gone.

666 words, about 3 min 5

External Clients Bottlenecked Behind a Single LoadBalancer VIP

An external reporting service outside the Kubernetes cluster connects to Cassandra through a single LoadBalancer Service that selects all 6 Cassandra pods on port 9042. The Java driver 4.x is configured with that one VIP as its contact point and uses LOCAL QUORUM .

738 words, about 4 min