MinIO is a high-performance, S3-compatible object storage server implemented in Go. It is a monolithic application that provides a full-featured object storage system supporting erasure coding, bitrot protection, IAM, replication, lifecycle management, and a web console. The codebase is organized around a central `cmd` package containing the server implementation, with extensive `internal` packages for subsystems like erasure coding, encryption, event notifications, and distributed locking. The architecture follows a distributed systems pattern where nodes communicate via custom REST protocols and a proprietary grid messaging system for internode communication. The system implements a sophisticated storage engine using Reed-Solomon erasure coding with support for multiple storage classes, bitrot detection via HighwayHash, and strong consistency guarantees. It supports a wide range of protocols including S3 API, FTP/SFTP, and S3 Select for SQL queries on stored objects. The codebase demonstrates advanced Go patterns including extensive use of build tags for platform-specific code, code generation for serialization (msgp), and a plugin-based architecture for external identity providers and KMS integration. Key architectural components include the erasure coding subsystem (`cmd/erasure*.go`), the object API layer (`cmd/object-api*.go`), the IAM system (`cmd/iam*.go`, `cmd/auth-handler.go`), and the distributed systems infrastructure (`internal/grid`, `internal/dsync`). The codebase shows significant investment in operational features including comprehensive metrics exposure via Prometheus, audit logging, batch jobs for large-scale operations, and extensive debugging tools. The project maintains high code quality with extensive testing, CI/CD pipelines, and support for multiple deployment modes including standalone, distributed, Kubernetes, and various cloud platforms.
RustFS is a production-grade, S3-compatible distributed object storage server implemented in Rust. The core system provides erasure-coded storage with healing, bitrot detection, bucket versioning, object locking, lifecycle management, replication (bucket and site), tiering to remote S3-compatible backends, KMS integration, IAM/OIDC/Keystone authentication, audit logging, event notifications, and an extensive observability layer. It also exposes non-S3 protocols including OpenStack Swift, SFTP, FTPS, and WebDAV, plus an admin/console API and an embedded server library for in-process testing and integration. The repository is a large Cargo workspace of roughly 50 crates, with the main `rustfs` binary orchestrating startup, HTTP/gRPC servers, background services, and protocol servers, while domain subsystems such as `ecstore`, `heal`, `scanner`, `replication`, `notify`, `kms`, `iam`, `obs`, and `targets` are isolated behind trait-based contracts and runtime-boundary modules.