Confluent Cloud vs Karapace

Confluent Cloud is a managed data streaming platform built on a serverless Apache Kafka engine. It is designed for real-time streaming, event-driven applications, analytics, and AI/ML workloads. Cluster choices include Basic, Standard, Enterprise, and Freight, as well as Dedicated clusters with pre-provisioned resources. Confluent says its cloud-native engine adjusts cluster infrastructure to workload needs. Cluster Linking replicates, synchronizes, and shares data across regions, public clouds, and organizations. The service includes managed Kafka connectors for databases, data lakes, and warehouses, serverless processing with Apache Flink, and a managed Stream Governance suite. Tableflow can materialize Kafka topics and schemas as Apache Iceberg and Delta Lake tables. Listed security features include RBAC, self-managed encryption keys, client-side field-level encryption, and audit logs. Users can manage clusters and topics through a web UI or CLI; supported client languages include Java, Python, .NET, Go, Node.js, and C/C++. It is available on AWS, Azure, and Google Cloud across more than 100 regions. A free plan is available; paid plans start at $385/mo, and new signups receive a 30-day trial.

Karapace is Aiven’s open-source Schema Registry and REST Proxy for Aiven for Apache Kafka. The registry stores and versions schemas, then checks compatibility before a changed schema is published. It accepts Avro, Protobuf, and JSON Schema, with references supported for Avro and Protobuf. Compatibility modes include NONE, BACKWARD, BACKWARD_TRANSITIVE, FORWARD, FORWARD_TRANSITIVE, FULL, and FULL_TRANSITIVE. The REST Proxy exposes HTTP endpoints for producing and consuming Kafka events, so scripts, curl, and HTTP services can work with events. OAuth 2.0/OIDC authentication is available for both components. Registry ACLs and OIDC role-based rules can limit operations, including by HTTP method. Example identity providers include Auth0, Okta, Google Identity Platform, and Azure. Deployment documentation covers Docker and installation from source with pip; the API is stated to support Schema Registry 6.1.1 operations. Karapace is available in Aiven’s Kafka free tier for learning, prototyping, and evaluation. The Free plan costs nothing, while Developer costs $35 a month.