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Apache Pulsar

pulsar.apache.org

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Spec score 8.2 #6 of 26 in Schema Registry Software

What it is

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.

Spec sheet

What it does
Apache Pulsar is an open-source, distributed messaging and streaming platform built for the cloud.Read 29 Sep 2026 · pulsar.apache.org
Deployment
Pulsar can run in Docker or Kubernetes, and the project offers a Helm chart for Kubernetes deployment.Read 29 Sep 2026 · pulsar.apache.org
Integrations
Built-in connectors import and export data for systems including Kafka, RabbitMQ, MySQL, PostgreSQL, MongoDB, Cassandra, and Elasticsearch.Read 29 Sep 2026 · pulsar.apache.org
Maker
The Apache Software Foundation is a nonprofit organization that provides software for the public good.Read 29 Sep 2026 · apache.org
Clients
Officially maintained client libraries are available for Java, Go, Python, C++, Node.js, and C#.Read 29 Sep 2026 · pulsar.apache.org
Geo-replication
Pulsar supports configurable replication across geographic regions and automatic client failover to healthy clusters.Read 29 Sep 2026 · pulsar.apache.org
Latency and scale
Pulsar supports message consumption with less than 10 ms latency and up to one million unique topics in a single cluster.Read 29 Sep 2026 · pulsar.apache.org
Notable release limit
The 5.0.0-M2 milestone is intended for early testing and feedback and is not meant for production use.Read 29 Sep 2026 · pulsar.apache.org
Release integrity
Pulsar release files have OpenPGP signatures and SHA-512 checksums for integrity verification.Read 29 Sep 2026 · pulsar.apache.org
Security controls
Pulsar provides encryption, pluggable authentication, and authorization controls, but these are not enabled by default.Read 29 Sep 2026 · pulsar.apache.org
Serverless processing
Pulsar Functions process messages using user-defined logic and support Java, Python, and Go.Read 29 Sep 2026 · pulsar.apache.org
Storage and retention
Tiered storage can offload data from BookKeeper to blob storage such as S3 for unlimited retention.Read 29 Sep 2026 · pulsar.apache.org
Tenancy and access
Tenants and policies let organizations control access to data and actions, and isolate brokers for noisy-neighbor protection.Read 29 Sep 2026 · pulsar.apache.org

Plans and prices

Apache Pulsar Free Open-source distributed messaging and streaming platform · Apache License 2.0 Read 29 Sep 2026 · pulsar.apache.org

Every Apache Pulsar plan and price →

Strong points and limits

Strong points

  • Supports less than 10 ms message-consumption latency.
  • Supports up to one million unique topics per cluster.
  • Offers geographic replication and automatic client failover.
  • Built-in connectors cover several databases and messaging systems.
  • Can run in Docker or Kubernetes.

Limits

  • Encryption, authentication, and authorization are not enabled by default.
  • The 5.0.0-M2 milestone is not meant for production use.

Who it suits

Pulsar suits teams building messaging or streaming systems that need geographic replication, multiple client languages, or connectors to listed data systems. Operators should account for its security controls being off by default.

Verdict

Pulsar combines messaging, streaming, connectors, and tiered storage in a self-hosted platform. Configure its security controls before use, and treat the 5.0.0-M2 milestone as a testing release.

Where Specifiction places it

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