Apache Pulsar vs Apicurio 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.

Apicurio Registry is an open-source runtime server for storing API designs and schemas as artifacts. Users can add, update, and remove artifacts through a remote REST API. For API discovery, teams can register designs such as OpenAPI, AsyncAPI, and GraphQL so consumers can search and browse APIs, see details, and read generated documentation. For messaging and event streaming, it provides a central place to track schemas and manage data-format evolution. Supported artifact types include OpenAPI, AsyncAPI, GraphQL, Apache Avro, Protocol Buffers, JSON Schema, Kafka Connect schema, WSDL, XML Schema, and ODCS v3.1. Configurable rules can check validity, compatibility, and integrity as artifacts change. Listed storage backends include Apache Kafka, PostgreSQL, and Microsoft SQL Server. Management options include a web console, REST API, command line, Maven plug-in, and Java client. Kafka serializers and deserializers can enforce schemas in producer and consumer applications. The documentation covers self-hosted deployment, including Kubernetes. The quick-start in-memory server is non-persistent and is not intended for production.