ClickHouse is an open-source, column-oriented database built for OLAP workloads, running complex analytical queries across large datasets with sub-second latency. The official ClickHouse Kubernetes Operator manages ClickHouse and Keeper clusters as CRDs, automating setup, scaling, and upgrades. This guide deploys the operator, a 3-node Keeper coordination group, and a 2-replica ClickHouse cluster with TLS, then verifies replication and connects both internally and externally. By the end, you'll have a ClickHouse cluster running on Kubernetes with encrypted client connections.
Prerequisite: Kubernetes cluster sized for 3 Keeper pods + 2 ClickHouse replicas, production clusters want 3+ nodes with 8 vCPUs and 16 GB RAM each. kubectl and Helm on your workstation.
Architecture
ClickHouse Keeper — 3-node coordination group; tracks replication and elects a leader. Each node persists to its own PVC.
ClickHouse Cluster — 2-replica database cluster. ReplicatedMergeTree uses Keeper to sync data across replicas.
