Schema Registry

The Schema Registry in Condense is available as part of a managed Kafka deployment. It allows users to view schema subjects, check schema versions, manage compatibility settings, and access the registry endpoint used by applications. This documentation explains how to use the Schema Registry inside Condense.

Accessing the Schema Registry

1. Log in to the Condense Console.

2. Go to Manage → Kafka Management.

3. Select Schema Registry from the left navigation panel.

You will see:

• A list of subjects on the left

• Schema details and versions on the right

Understanding Subjects

A subject represents the schema defined for a Kafka topic’s key or value.

Selecting a subject displays its:

• Compatibility Level

• Version history

• Schema ID for each version

• Available actions

Viewing Schema Versions

After selecting a subject, Condense shows a table with all schema versions registered under that subject. Each version entry includes:

• Version number

• Schema ID

• Actions (such as viewing the schema)

Selecting a version displays the schema associated with that version.

Compatibility Levels

Each subject displays a Compatibility Level. Condense also exposes a Global Compatibility Level at the top of the page.

These settings determine how schemas can evolve. Users can view:

• The global compatibility value (read-only if locked)

• The subject-specific compatibility value

Compatibility can be updated using the Schema Registry API.

Viewing the Registry URL

Condense provides a way to view the internal URL of the Schema Registry.

To access it:

1. Click the link icon in the top-right corner of the Schema Registry page.

2. A modal appears titled View Registry URL.

3. The modal displays the hostname and port used by client applications

4. Use this URL in Kafka producers/consumers that interact with schemas.

Registering and Managing Schemas (API)

Users can add, update, validate, or delete schemas using the Schema Registry API exposed through the internal load balancer.

Register a new schema version

curl -X POST -H "Content-Type: application/vnd.schemaregistry.v1+json" \
     --data '{"schema": "{\"type\": \"string\"}"}' \
     http://<internal-lb-ip>:8081/subjects/Kafka-key/versions

List all subjects

curl -X GET http://<internal-lb-ip>:8081/subjects

List schema versions for a subject

curl -X GET http://<internal-lb-ip>:8081/subjects/Kafka-value/versions

Fetch schema by global ID

curl -X GET http://<internal-lb-ip>:8081/schemas/ids/1

Fetch the latest schema

curl -X GET http://<internal-lb-ip>:8081/subjects/Kafka-value/versions/latest

Delete a specific version

curl -X DELETE http://<internal-lb-ip>:8081/subjects/Kafka-value/versions/3

Delete all versions

curl -X DELETE http://<internal-lb-ip>:8081/subjects/Kafka-value

Test compatibility

curl -X POST -H "Content-Type: application/vnd.schemaregistry.v1+json" \
     --data '{"schema": "{\"type\": \"string\"}"}' \
     http://<internal-lb-ip>:8081/compatibility/subjects/Kafka-value/versions/latest

View global compatibility

curl -X GET http://<internal-lb-ip>:8081/config

Update global compatibility

curl -X PUT -H "Content-Type: application/vnd.schemaregistry.v1+json" \
     --data '{"compatibility": "NONE"}' \
     http://<internal-lb-ip>:8081/config

Update compatibility for a subject

curl -X PUT -H "Content-Type: application/vnd.schemaregistry.v1+json" \
     --data '{"compatibility": "BACKWARD"}' \
     http://<internal-lb-ip>:8081/config/Kafka-value

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What You Can Do in the Condense UI

Using only the UI, users can:

• Browse all schema subjects

• View schema versions

• Inspect version numbers and Schema IDs

• View compatibility settings

• Copy the Registry URL for application integration

Schema creation, updates, and deletions are handled through the API.

The Schema Registry in Condense provides:

• A UI for viewing subjects and schema versions

• A modal to retrieve the internal Schema Registry URL

• Visibility into global and subject-level compatibility settings

• A fully functional REST API for schema registration, validation, and evolution

This enables users to manage Kafka schema lifecycle directly within Condense.