Kubernetes

Apache Druid Extension to enable using Kubernetes API Server for node discovery and leader election. This extension allows Druid cluster deployment on Kubernetes without Zookeeper. It allows running multiple Druid clusters within same Kubernetes Cluster, See config below.

This extension works together with HTTP based segment and task management in Druid. Consequently, following configurations must be set on all Druid nodes.

For Node Discovery, Each Druid process running inside a pod “announces” itself by adding few “labels” and “annotations” in the pod spec. Druid process needs to be aware of pod name and namespace which it reads from environment variables and POD_NAMESPACE. These variable names can be changed, see configuration below. But in the end, each pod needs to have self pod name and namespace added as environment variables.

Gotchas

• All Druid Pods belonging to one Druid cluster must be inside same kubernetes namespace.