Amazon EventBridge vs Google Cloud Pub/Sub

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.

Google Cloud Pub/Sub is a cloud messaging service for asynchronous communication between services that produce messages and those that process them. It is intended for service-to-service use, including streaming analytics, data integration, middleware, and parallel task queues, rather than direct communication with end users or IoT clients. Communication typically has latency around 100 milliseconds. Synchronous cross-zone replication and per-message receipt tracking provide at-least-once delivery; Dataflow supports exactly-once processing of Pub/Sub streams. There are no shards or partitions, and provisioning scales automatically after quota is set. Message controls include seek and replay, dead letter topics, and attribute-based filtering. Pub/Sub offers fine-grained access controls, end-to-end encryption, and HIPAA compliance. It supports REST and gRPC APIs and client libraries for seven languages; API keys are not supported for authentication. The maximum message size is 10 MB. The free monthly tier is free for the first 10 GB of data per month. Pay-as-you-go is $40 a month beyond 10 GB, with throughput listed at $40 per TB and storage at $0.27 per GiB-month.