Apache Pulsar

Apache Pulsar is a cloud-native, multi-tenant, high-performance solution for server-to-server messaging and queuing built on the publisher-subscribe (pub-sub) pattern. Pulsar combines the best features of a traditional messaging system like RabbitMQ with those of a pub-sub system like Apache Kafka – scaling up or down dynamically without downtime. It's used by thousands of companies for high-performance data pipelines, microservices, instant messaging, data integrations, and more.

Features:

Cloud-native A multiple layer approach separating compute from storage to work with cloud infrastructures and Kubernetes.

Serverless functions Write serverless functions with developer-friendly APIs to natively process data immediately upon arrival. No need to run your own stream processing engine.

Horizontally scalable Expand capacity seamlessly to hundreds of nodes.

Low latency with durability Low publish latency (< 5ms) at scale with strong durability guarantees.

Geo-replication Configurable replication between data centers across multiple geographic regions.

Multi-tenancy Built from the ground up as a multi-tenant system. Supports isolation, authentication, authorization, and quotas.

Persistent storage Persistent message storage based on Apache BookKeeper. IO-level isolation between write, and read operations.

Client libraries Flexible messaging models with high-level APIs for Java, Go, Python, C++, Node.js, WebSocket and C#.

Operability REST Admin API for provisioning, administration, tools and monitoring. Can be deployed on bare metal, Kubernetes, Amazon Web Services(AWS), and DataCenter Operating System(DC/OS).