Apache Pulsar vs WarpStream BYOC Schema Registry

Apache Pulsar is a free, open-source distributed messaging and streaming platform built for cloud use. It supports message consumption with less than 10 ms latency and up to one million unique topics in a cluster. Configurable replication across geographic regions and automatic client failover to healthy clusters support multi-region deployments. Tenants and policies control access to data and actions, and can isolate brokers to limit noisy-neighbor effects. Maintained client libraries are available for Java, Go, Python, C++, Node.js, and C#. Built-in connectors move data to and from systems including Kafka, RabbitMQ, MySQL, PostgreSQL, MongoDB, Cassandra, and Elasticsearch. Pulsar Functions process messages with user-defined logic in Java, Python, or Go. Tiered storage can offload data from BookKeeper to blob storage such as S3 for unlimited retention. It can run in Docker or Kubernetes, with a Helm chart for Kubernetes. Encryption, authentication, and authorization are available but are not enabled by default. The 5.0.0-M2 milestone is for early testing and feedback, not production use.

WarpStream BYOC Schema Registry stores and serves schemas for Kafka records through a REST server compatible with Confluent’s Schema Registry API. It supports Avro and protobuf, while WarpStream Agents validate records and can reject invalid data or emit metrics. The stateless, zero-disk registry stores schemas in the customer’s object storage, and WarpStream says they remain in that cloud account. Schema Linking migrates schemas from a Confluent-compatible registry while preserving IDs and compatibility rules. Authentication options include Basic Authentication, TLS and mutual TLS. Customers create a Schema Registry Virtual Cluster in the console or API, then deploy an agent using the Kafka Agents binary; agents emit logs and metrics. Each registry allows 100,000 schema versions and each schema 1 MB, with support-requested increases. Plans are Dev at $0.03 a month, Fundamentals at 0.17 USD, Pro at 0.52 USD, and Enterprise with no listed price. Cluster minutes use 15-minute billing intervals.