Confluent Cloud vs Google Cloud Pub/Sub

Confluent Cloud is a managed data streaming platform built on a serverless Apache Kafka engine. It is designed for real-time streaming, event-driven applications, analytics, and AI/ML workloads. Cluster choices include Basic, Standard, Enterprise, and Freight, as well as Dedicated clusters with pre-provisioned resources. Confluent says its cloud-native engine adjusts cluster infrastructure to workload needs. Cluster Linking replicates, synchronizes, and shares data across regions, public clouds, and organizations. The service includes managed Kafka connectors for databases, data lakes, and warehouses, serverless processing with Apache Flink, and a managed Stream Governance suite. Tableflow can materialize Kafka topics and schemas as Apache Iceberg and Delta Lake tables. Listed security features include RBAC, self-managed encryption keys, client-side field-level encryption, and audit logs. Users can manage clusters and topics through a web UI or CLI; supported client languages include Java, Python, .NET, Go, Node.js, and C/C++. It is available on AWS, Azure, and Google Cloud across more than 100 regions. A free plan is available; paid plans start at $385/mo, and new signups receive a 30-day trial.

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.