Amazon EventBridge vs Apache Pulsar

Amazon EventBridge is a serverless event broker for applications that respond to events from applications, SaaS services, and AWS services. Event buses route events across AWS accounts, and subscriptions can combine filters, targets, and retry policies. Buses support tens of thousands of subscribers, retention for up to 365 days, and JSON, Avro, Protobuf, and Cloud Events formats. EventBridge also supports ordered delivery and sharing a bus across accounts in an AWS Organization through AWS Resource Access Manager. Pipes connect endpoints point to point, with optional transformation, filtering, and enrichment. Supported SaaS sources can route events to AWS service targets; listed partners include Adobe, Datadog, MongoDB, Shopify, Stripe, and Snyk. API destinations send events from a bus or pipe to web applications on public or private networks. Monitoring uses CloudWatch metrics, with logging to CloudWatch Logs, S3, or Kinesis Data Firehose. IAM access controls, VPC endpoints, and TLS 1.2 encryption in transit are supported. AWS lists several compliance standards and HIPAA eligibility, while customers retain responsibility for their own compliance obligations.

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.