CosmoS3 1.7.0

CosmoS3

An Amazon S3-compatible object storage server built on CosmoApiServer.Core.

NuGet Package

dotnet add package CosmoS3

Quick Start (Executable Host)

dotnet run --project src/CosmoS3.Host

Example Configuration

Create src/CosmoS3.Host/appsettings.json (SQLite example):

{
  "Port": 8100,
  "ValidateSignatures": false,
  "HeaderApiKey": "x-api-key",
  "AdminApiKey": "changeme-admin-key",
  "RegionString": "us-east-1",
  "Database": {
    "DatabaseType": "sqlite",
    "ConnectionString": "Data Source=./data/cosmos3.db;"
  },
  "Storage": {
    "StorageType": "Disk",
    "DiskDirectory": "./disk/",
    "TempDirectory": "./temp/"
  }
}

Run

dotnet run --project src/CosmoS3.Host

Example (SQL Server)

Set DatabaseType to mssql:

{
  "Database": {
    "DatabaseType": "mssql",
    "ConnectionString": "Server=localhost,1433;Database=cosmos3;User Id=sa;Password=YourPassword;TrustServerCertificate=True;"
  }
}

Performance

CosmoS3 is optimized for high-throughput streaming. Recent benchmarks using the MinIO warp tool show that CosmoS3's asynchronous, pipeline-based architecture allows it to compete with and sometimes exceed specialized S3 servers for common workloads.

Benchmark: CosmoS3 vs. MinIO (Throughput in MiB/s)

Benchmarks conducted on local NVMe storage using SQLite for metadata. Higher concurrency performance (+240% throughput gain over previous versions) was achieved by eliminating thread-blocking calls and optimizing database indexing.

Features

• S3 service operations: list buckets, service exists.
• Buckets: create/delete, list objects, location, ACLs, tags, versioning, website config, list versions, list multipart uploads.
• Objects: PUT/GET/HEAD, range GET, copy (server-side), delete, multi-delete, ACLs, tags.
• Multipart upload: initiate, upload part, list parts, complete, abort.
• Authentication: Signature V4, Signature V2, presigned URLs.
• URL styles: path-style and virtual-hosted-style buckets.
• Static website hosting: index document, redirects, routing rules.
• Storage: disk backend (pluggable storage driver interface).
• Metadata: SQL-backed (SQLite, PostgreSQL, MySQL, SQL Server).
• Admin API: header-based admin access (HeaderApiKey/AdminApiKey).
• CORS and basic logging controls via appsettings.json.

For deeper details, see src/CosmoS3/README.md.

Supported Databases

Configuration

Each host reads from appsettings.json. See samples/CosmoS3Host.SQLite/appsettings.json for an example.

License

MIT