AWS Glue Schema Registry vs Google Cloud Pub/Sub

AWS Glue Schema Registry is a free cloud service for centrally discovering, controlling, and evolving schemas used by streaming applications. It supplies serializers and deserializers so producers and consumers can share schema definitions during data exchange. Supported formats are Avro v1.11.4, JSON Schema Draft-04, Draft-06, and Draft-07, plus Protocol Buffers proto2 and proto3; Protobuf extensions and groups are not supported. Eight compatibility modes are available: NONE, DISABLED, BACKWARD, BACKWARD_ALL, FORWARD, FORWARD_ALL, FULL, and FULL_ALL. Features include automatic registration, metadata-based schema sourcing, IAM compatibility, and optional ZLIB compression. Documented integrations cover Apache Kafka, Amazon MSK, Kinesis Data Streams, Amazon Managed Service for Apache Flink, AWS Lambda, AWS Glue streaming, and Apache Kafka Streams. Client API traffic uses TLS over HTTPS, and schemas are encrypted at rest with an AWS KMS service-managed key. Registry ARNs organize permissions for schema operations.

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.