Persisting Schema Registry with PostgreSQL

2 minute read

Updated: May 04, 2026

If you deploy the Cloudera Schema Registry using the default Helm values, it uses an in-memory database. This means that if your pod crashes or restarts (e.g., from an Out of Memory error), all of your registered schemas instantly vanish.

To make your schemas immortal, we need a persistent backend. While you could spin up a dedicated database, a much more efficient approach for this lab is to piggyback on the PostgreSQL instance already running for SQL Stream Builder (SSB).

Here is how to create a dedicated user and database for Schema Registry inside the existing SSB Postgres pod.

Setup the Database and User

First, find the name of your SSB Postgres pod:

kubectl get pods -n cld-streaming | grep postgres

Next, execute into the pod to create the database, create a dedicated registry user, and grant the proper ownership. (Replace <ssb-postgresql-pod-name> with your actual pod name):

# Create the database
kubectl exec -it <ssb-postgresql-pod-name> -n cld-streaming -- psql -U postgres -c "CREATE DATABASE registry;"

# Create the dedicated user
kubectl exec -it <ssb-postgresql-pod-name> -n cld-streaming -- psql -U postgres -c "CREATE USER registry WITH PASSWORD 'cloudera';"

# Grant ownership to the new user
kubectl exec -it <ssb-postgresql-pod-name> -n cld-streaming -- psql -U postgres -c "ALTER DATABASE registry OWNER TO registry;"

Create the Kubernetes Secret

The Schema Registry Helm chart strictly requires passwords to be passed via a Kubernetes Secret. Run this command to store our password:

kubectl create secret generic sr-db-pass \
  --from-literal=password=cloudera \
  --namespace cld-streaming

Full Helm Values Configuration

Create a file named sr-values-postgres.yaml with the full configuration. This disables TLS/OAuth for the lab, sets up the PostgreSQL connection using the secret we just created, and adds resource limits to prevent OOM restarts.

tls:
  enabled: false
authentication:
  oauth:
    enabled: false
authorization:
  simple:
    enabled: false
database:
  type: postgresql
  jdbcUrl: "jdbc:postgresql://ssb-postgresql.cld-streaming.svc:5432/registry"
  username: "registry"
  password:
    secretKeyRef:
      name: "sr-db-pass"
      key: "password"
service:
  type: NodePort
resources:
  requests:
    memory: "512Mi"
    cpu: "500m"
  limits:
    memory: "1Gi"
    cpu: "1000m"

Install and Verify

Now, run the full Helm install command to deploy Schema Registry with your new configuration:

helm install schema-registry \
--namespace cld-streaming \
--version 1.6.0-b99 \
--values sr-values-postgres.yaml \
--set "image.imagePullSecrets[0].name=cloudera-creds" \
oci://container.repository.cloudera.com/cloudera-helm/csm-operator/schema-registry 

Check the status of your pods to ensure they initialize successfully. The init container will authenticate as the new registry user and permanently persist your schemas!

kubectl get pods -l app=schema-registry -n cld-streaming -w