Apache Pulsar vs Kafka: Key Differences

Aspect Apache Pulsar Apache Kafka
Architecture Separates storage and serving layers using Apache BookKeeper for storage and brokers for message routing. Combines storage and serving layers, with brokers handling both message routing and storage.
Scalability Designed for horizontal scalability by adding brokers to increase processing capacity. Scalable, but requires careful configuration of brokers, ZooKeeper, and RocksDB.
Performance Better throughput and latency in some benchmarks, optimized for high-performance tasks. Performance can be improved through careful configuration and tuning.
Message Delivery Supports all message delivery models: at-most-once, at-least-once, and exactly-once out of the box. Primarily supports at-least-once; additional configuration is needed for exactly-once delivery.
Multi-Tenancy Native support for multi-tenancy, with isolated namespaces and resource allocation. Limited support for multi-tenancy, requiring extra configuration and management.
Geo-Replication Built-in support for geo-replication across multiple regions. Requires additional configuration for geo-replication.
Security Comprehensive security with SSL/TLS, SASL, and Kerberos built-in. Supports encryption and authentication but requires more manual configuration.
Ecosystem Growing ecosystem, but still behind Kafka in terms of breadth and depth. More mature ecosystem with a wide range of connectors, integrations, and tools.
Community Smaller but active and growing community. Larger, well-established community with thousands of contributors.

Use Cases

Apache Pulsar Apache Kafka
  • Real-time data processing with high throughput and low latency
  • IoT and edge computing applications
  • Complex event-driven systems
  • Event-driven architecture
  • Cloud-native applications
  • Business-critical data processing

Conclusion

Apache Pulsar and Kafka are powerful platforms that cater to different use cases. Pulsar excels in multi-tenancy, geo-replication, and high-performance streaming, while Kafka’s mature ecosystem and community make it a popular choice for event-driven architectures and traditional data processing. Choose based on your specific use case and ecosystem requirements.