Apache Iggy and RobustMQ are both modern message queue systems written in Rust, emphasizing high performance, scalability, and developer-friendliness. Currently, Iggy has joined the Apache Software Foundation. RobustMQ is often compared with Iggy, and people frequently ask about the differences between them.
Note: RobustMQ is still in early development. This article focuses on the differences in positioning and product design plans. Some of RobustMQ’s features are still under active development.
Note: The goal of this article is to clearly explain the differences between Iggy and RobustMQ. The comparison is based on personal understanding and perspective, and may contain biases. Feedback and discussion are very welcome.
Summary
Positioning
Iggy is a high-performance, high-throughput streaming platform that can be seen as an alternative to Kafka. More precisely, it's a simplified and modern Kafka-style message queue system. It is a new message queue platform with its own protocol and SDK.
RobustMQ is designed as an all-in-one message queue that adapts to current mainstream messaging protocols (Kafka, AMQP, MQTT, etc.) and is built with a fully serverless architecture. Its goal is to be compatible with existing protocols, SDKs, and ecosystems, while solving current messaging system problems related to elasticity, cost, and fragmented features through architecture upgrades (Rust performance/safety, compute/storage/scheduling separation, pluggable storage).
Technical Philosophy
- Architecture: Iggy uses a monolithic (compute+storage) architecture, while RobustMQ adopts a decoupled and layered architecture (compute/storage/scheduling separation), providing greater elasticity.
- Protocol and SDK: Iggy uses a custom protocol and requires custom multi-language SDKs. RobustMQ uses standard open protocols and does not require private SDKs.
- Storage Layer: Iggy uses local append-only log storage, while RobustMQ supports pluggable storage, including HDFS, S3, MinIO, memory, and local storage. RobustMQ offers more flexibility and elasticity.
- Client Integration: Iggy requires clients to use its specific SDK. RobustMQ supports out-of-the-box use of open-source Kafka, AMQP, or MQTT SDKs, making it easier to integrate.
- Ecosystem Compatibility: Iggy requires users to adapt to a new ecosystem. RobustMQ is fully compatible with mainstream MQ ecosystems and tools, with near-zero switching cost.
Core Design Philosophy Comparison
Iggy's Philosophy
- A simple yet modern Kafka alternative
- Lightweight and suitable for embedded or self-hosted use
- Avoids complexity from ZooKeeper/KRaft
- Focused on performance and Rust-native safety
RobustMQ's Philosophy
- A unified enterprise message backbone for multi-protocol, multi-model messaging
- One system to handle Kafka / MQTT / AMQP protocols
- Supports complex deployments (cloud-edge collaboration, decoupled architecture)
- More like a modern enterprise service bus
Feature Comparison Table
| Feature / Item | Apache Iggy | RobustMQ |
|---|---|---|
| Language | Rust | Rust |
| Positioning | Kafka replacement (modern, lightweight) | Unified message hub with multi-protocol support |
| Protocol Support | Custom protocol (lightweight), TCP, HTTP | Kafka / AMQP / MQTT and more |
| SDKs | Iggy's own SDK | Kafka / AMQP / MQTT standard open-source SDKs |
| Topic & Partition | Supported | Supported with fine-grained control |
| Storage Layer | Local file-based append-only log | Pluggable: local file, S3, MinIO, memory, etc. |
| Architecture | Leader-follower, stream-oriented | Layered: storage/compute/scheduling separated |
| Distributed Support | Experimental (basic clustering) | Full distributed support with scaling and replication |
| Performance | Memory-mapped files, Rust-optimized | Same (Rust, mmap, optimized pipeline) |
| Message Model | Kafka-style (topic + offset) | Unified model (Pub/Sub, queue, delayed, broadcast) |
| Use Cases | High-throughput log streaming, Kafka alt. | Multi-source integration, edge computing, IoT, microservices |
| Advanced Features | Focused on throughput | Supports broadcast, private messages, priority queues |
| Ecosystem | CLI, HTTP, SDK in Iggy's ecosystem | Fully compatible with Kafka / AMQP / MQTT tools |
| Maturity | Medium (actively developed) | Medium (actively developed) |
| Integration Cost | High (business must adopt Iggy ecosystem) | Low (drop-in compatible with existing protocol SDKs) |
| License | Apache 2.0 | Apache 2.0 |