Remote Debug Java Application running on Kubernetes Cluster

HiveServer2-Remote-Debug-on-Kubernetes.md

Following steps can be used to debug java application running on Remote Cluster, for sake of similicity I am using bare minimum pod config to spin the HS2 pod on the cluster.

1. Build a docker image as per https://gist.github.com/rajkrrsingh/e2a5d02a3a895c7f7e8f1d6d0e71e0e9, The image push the debug config -agentlib:jdwp=transport=dt_socket,address=8000,server=y,suspend=n to the JVM opts, the same can be achieved through the ConfigMap descriptor.

2. Create HS2 Deployments

apiVersion: apps/v1
kind: Deployment
metadata:
  name: hs2
  namespace: default
  labels:
    app: hs2
spec:
  replicas: 1
  selector:
    matchLabels:
      app: hs2
  template:
      metadata:
        labels:
          app: hs2
      spec:
        containers:
          - name: hs2
            image: rajkrrsingh/hive3-image-debug:latest
            imagePullPolicy: Always
            ports:
              - containerPort: 10000
                name: binary

3. port forwards

// JDBC endpoint
kubectl port-forward --address 0.0.0.0  hs2-5d6d47b5bd-d86tm 10000:10000
// Debugger endpoint
kubectl port-forward --address 0.0.0.0  hs2-5d6d47b5bd-d86tm 8000:8000

4. Now though IDE you can connect the debugger to Kubernetes node on port 8000 and start debugging.