Apache Qpid Broker-J vs Google Cloud Pub/Sub

Apache Qpid Broker-J is free, open-source Java message-broker software for self-hosted deployments. It stores, routes and forwards messages using AMQP, supporting versions 0-8, 0-9, 0-9-1, 0-10 and 1.0, plus AMQP over WebSockets. Administration is available through REST, AMQP Management and a web console. Routing and queue features include header-based routing, message groups, server-side selectors, dead-letter queues, and last-value, priority and sorted queues. Pluggable persistence supports Derby, SQL and BDB stores. Listed operational features include high availability, producer flow control and flow to disk. Authentication can use LDAP, Kerberos, OAuth2 or SSL client certificates; access control lists and SSL secure connections are supported. The listed current release is 10.1.1, with source archives and tar.gz or zip binaries. Installation documentation covers Windows and UNIX systems. The project uses Apache License 2.0.

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.