Amazon SNS vs Eclipse Amlen

Amazon SNS is a managed publish/subscribe service for sending messages between applications and reaching people. It can deliver notifications to application endpoints and send SMS, mobile push, and email. Standard topics support nearly unlimited messages per second with best-effort ordering and deduplication; FIFO topics preserve order and prevent duplicate delivery within five minutes, with limits of 3,000 messages per second or 10 MB per second per topic. Publishers can batch 1 to 10 messages per request, while subscribers can filter notifications. Integrations include AWS event sources and destinations such as SQS, Data Firehose, Lambda, and HTTPS. Each message can contain up to 256 KB; the Extended Client Library can store payloads up to 2 GB in S3 and publish an object reference. SNS retries delivery and supports dead-letter queues. The free tier includes 1 million requests, 100,000 HTTP notifications, and 1,000 email notifications each month. Listed paid rates include $0.50 per month for API requests, $0.06 for HTTP deliveries, and $2.00 for email deliveries; charges depend on usage.

Eclipse Amlen is a self-hosted MQTT server for IoT and web messaging. It supports MQTT versions 3 through 5 over TCP/IP and WebSockets, plus JMS, and can convert messages between MQTT and JMS. A protocol plug-in SDK lets users add other protocols, including options for legacy sensors that cannot use MQTT. The Amlen Bridge forwards MQTT messages to another MQTT server or IBM Event Streams for IBM Cloud, with filtering, topic mapping, multiple forwarders, and REST API configuration and monitoring. Security controls include TLS profiles, user ID and password authentication against a configured LDAP server, and policy-based authorization for connections, topics, subscriptions, and queues. Administrators can manage message hubs and endpoints through a WebUI or REST Administration APIs. Supported client platforms include C, Java, Android, iOS, and JavaScript. Server and WebUI downloads are listed for RHEL and AlmaLinux 8, 9, and 10. The free software has configurable delivery guarantees. One limitation is that Amlen supports a single LDAP server connection, so users and groups must be provided through that server.