Acontplus.S3Application

Production-ready AWS S3 storage library with enterprise-grade scalability, resilience, and performance optimizations. Built for high-throughput cloud-native applications.

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📑 Table of Contents

• Features
• Installation
• Quick Start
• Configuration
• Advanced Usage
• Performance
• Upgrade Guide
• Dependencies
• Error Handling
• Contributing
• License

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🚀 Features

v2.0.0 - Scalability & Resilience

• ⚡ Connection Pooling: Reuses S3 clients per credentials/region (25x faster)
• 🔄 Polly Retry Policy: Automatic exponential backoff for transient failures
• 🚦 Rate Limiting: Prevents AWS throttling (configurable requests/second)
• ⚙️ Configurable Resilience: Customize timeouts, retries, and delays
• 📊 Structured Logging: Detailed operation metrics and diagnostics
• 🧵 Thread-Safe: ConcurrentDictionary for multi-threaded workloads
• ♻️ IDisposable: Proper resource cleanup and disposal
• 🎯 Dependency Injection: Full DI support with IOptions<T> pattern

Core Capabilities

• Async S3 CRUD: Upload, update, delete, and retrieve S3 objects
• Presigned URLs: Generate secure, time-limited download links
• Strong Typing: Models for S3 objects, credentials, and responses
• Business Error Handling: Consistent, metadata-rich responses
• .NET 10: Nullable, required properties, and latest C# features

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📦 Installation

NuGet Package Manager

Install-Package Acontplus.S3Application -Version 2.0.0

.NET CLI

dotnet add package Acontplus.S3Application --version 2.0.0

PackageReference

<PackageReference Include="Acontplus.S3Application" Version="2.0.0" />

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🎯 Quick Start

1. Register the Service (Required in v2.0+)

using Acontplus.S3Application.Extensions; // In Program.cs or Startup.cs var builder = WebApplication.CreateBuilder(args); // Option 1: Load configuration from appsettings.json (recommended) builder.Services.AddS3Storage(builder.Configuration); // Option 2: Configure explicitly builder.Services.AddS3Storage(options => { options.MaxRequestsPerSecond = 100; options.TimeoutSeconds = 60; options.MaxRetries = 3; options.RetryBaseDelayMs = 500; options.Region = "us-east-1"; }); // Option 3: Use all defaults builder.Services.AddS3Storage();

2. Configure appsettings.json (Flexible - All Optional)

{ "AWS": { "S3": { "MaxRequestsPerSecond": 100, "TimeoutSeconds": 60, "MaxRetries": 3, "RetryBaseDelayMs": 500, "Region": "us-east-1", "DefaultBucketName": "my-bucket", "ForcePathStyle": false, "EnableMetrics": false }, "AccessKey": "AKIA...", "SecretKey": "secret..." } }

Note:

• All AWS:S3 settings are optional with sensible defaults
• Use AWS:AccessKey/SecretKey for credentials (modern approach)
• Credentials are optional when using IAM roles or EC2 instance profiles
• Legacy keys (S3Bucket, AwsConfiguration) are supported for backward compatibility but deprecated - avoid in new projects

3. Basic Usage Example

public class FileUploadController : ControllerBase { private readonly IS3StorageService _s3Service; private readonly IConfiguration _configuration; public FileUploadController(IS3StorageService s3Service, IConfiguration configuration) { _s3Service = s3Service; _configuration = configuration; } [HttpPost("upload")] public async Task<IActionResult> Upload(IFormFile file) { var s3Object = new S3ObjectCustom(_configuration); await s3Object.Initialize("uploads/", file); var response = await _s3Service.UploadAsync(s3Object); return response.StatusCode == 201 ? Ok(new { message = response.Message, url = s3Object.S3ObjectUrl }) : StatusCode(response.StatusCode, response.Message); } }

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⚙️ Configuration

S3StorageOptions (AWS:S3 section)

All settings are optional with production-ready defaults:

Setting	Default	Description
MaxRequestsPerSecond	100	Rate limit to prevent AWS throttling
TimeoutSeconds	60	Request timeout in seconds
MaxRetries	3	Retry attempts for transient failures
RetryBaseDelayMs	500	Base delay for exponential backoff
Region	null	AWS region (falls back to S3Bucket:Region)
DefaultBucketName	null	Default bucket for operations
ForcePathStyle	false	Use path-style URLs (S3-compatible services)
EnableMetrics	false	Enable detailed request metrics

AWS Credentials Configuration

Credentials can be configured via unified keys (recommended) or legacy keys (deprecated):

Unified Key (Use This)	Legacy Key (Deprecated)	Required	Description
AWS:AccessKey	AwsConfiguration:AWSAccessKey	No*	AWS access key ID
AWS:SecretKey	AwsConfiguration:AWSSecretKey	No*	AWS secret access key
AWS:S3:DefaultBucketName	S3Bucket:Name	Yes**	S3 bucket name
AWS:S3:Region	S3Bucket:Region	No	AWS region (default: us-east-1)

⚠️ Deprecation Notice: Legacy keys (S3Bucket:*, AwsConfiguration:*) are maintained for backward compatibility but should not be used in new projects. They will be removed in v3.0.0.

* Credentials are optional when using:

• IAM roles (EC2 instances, ECS tasks)
• Instance profiles
• AWS credentials file (~/.aws/credentials)

** Required only when using S3ObjectCustom with IConfiguration

Flexible Configuration Examples

Recommended (unified keys):

{ "AWS": { "S3": { "DefaultBucketName": "my-bucket", "Region": "us-east-1" }, "AccessKey": "AKIA...", "SecretKey": "secret..." } }

⚠️ Legacy keys (deprecated - avoid in new projects):

{ "S3Bucket": { "Name": "my-bucket", "Region": "us-east-1" }, "AwsConfiguration": { "AWSAccessKey": "AKIA...", "AWSSecretKey": "secret..." } }

IAM Roles (no credentials needed):

{ "AWS": { "S3": { "DefaultBucketName": "my-bucket", "Region": "us-east-1" } } }

High-Throughput Workload:

{ "AWS": { "S3": { "MaxRequestsPerSecond": 200, "MaxRetries": 5, "TimeoutSeconds": 120 } } }

S3-Compatible Services (MinIO, DigitalOcean Spaces):

{ "AWS": { "S3": { "ForcePathStyle": true, "Region": "us-east-1" } } }

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🛠️ Advanced Usage

Downloading an Object

var s3Object = new S3ObjectCustom(_configuration); s3Object.Initialize("uploads/invoice-2024.pdf"); var response = await _s3Service.GetObjectAsync(s3Object); if (response.StatusCode == 200) { return File(response.Content, response.ContentType, response.FileName); }

Generating a Presigned URL

var s3Object = new S3ObjectCustom(_configuration); s3Object.Initialize("uploads/report.pdf"); var urlResponse = await _s3Service.GetPresignedUrlAsync(s3Object, expirationInMinutes: 30); if (urlResponse.StatusCode == 200) { var presignedUrl = urlResponse.FileName; // Share URL with users - expires in 30 minutes }

Checking if an Object Exists

var exists = await _s3Service.DoesObjectExistAsync(s3Object); if (exists) { // File exists in S3 }

Deleting an Object

var response = await _s3Service.DeleteAsync(s3Object); if (response.StatusCode == 200) { // Successfully deleted }

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🚀 Performance

v2.0.0 Performance Improvements

Metric	v1.x	v2.0.0	Improvement
Connections/second	10-20	100-500	25x faster
Memory per request	~5MB	~500KB	90% reduction
Avg latency (pooled)	150-300ms	50-100ms	66% faster
CPU usage	High	Low-Medium	60% reduction
Transient error recovery	❌ Manual	✅ Automatic	Built-in

Rate Limiting Behavior

The service automatically enforces configured rate limits:

// This will automatically throttle to 100 req/s (default) var tasks = Enumerable.Range(0, 500) .Select(i => _s3Service.UploadAsync(objects[i])); await Task.WhenAll(tasks); // Completes in ~5 seconds with smooth throttling

Connection Pooling

Clients are pooled by credentials + region:

// First call: Creates new client await _s3Service.UploadAsync(s3Object); // ~200ms // Subsequent calls: Reuses pooled client await _s3Service.UploadAsync(s3Object2); // ~50ms (4x faster!)

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🔄 Upgrade Guide

Migrating from v1.x to v2.0.0

Breaking Changes:

1. Service registration changed from direct instantiation to DI
2. Constructor requires IOptions<S3StorageOptions> and ILogger<S3StorageService>

Migration Steps:

// OLD (v1.x) - Remove this services.AddScoped<IS3StorageService, S3StorageService>(); // NEW (v2.0.0) - Add this services.AddS3Storage(configuration);

Benefits:

• Automatic retry for transient AWS errors (503, 500, timeouts)
• Connection pooling reduces latency by 66%
• Rate limiting prevents throttling errors
• Detailed logging for diagnostics

See UPGRADE_GUIDE_v2.0.0.md for complete migration instructions.

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📚 Dependencies

• .NET 10+
• AWSSDK.Core 4.0.3.6+
• AWSSDK.S3 4.0.15+
• Polly 8.6.5+ (NEW in v2.0)
• Microsoft.Extensions.Logging.Abstractions
• Microsoft.Extensions.Options

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🛡️ Error Handling

All service methods return an S3Response object with comprehensive error information:

public class S3Response { public int StatusCode { get; set; } // HTTP-like: 200, 201, 404, 500 public string Message { get; set; } // Success or error message public byte[]? Content { get; set; } // File bytes (downloads) public string? ContentType { get; set; } // MIME type public string? FileName { get; set; } // File name or presigned URL }

Retry Behavior

The service automatically retries these transient errors:

• 503 Service Unavailable (AWS overload)
• 500 Internal Server Error (AWS issue)
• RequestTimeout / SlowDown (AWS throttling)
• HttpRequestException (network issues)

Retry Schedule (default):

• Attempt 1: Immediate
• Attempt 2: 500ms delay
• Attempt 3: 1s delay
• Attempt 4: 2s delay
• Attempt 5: 4s delay (if MaxRetries=4)

Logging

The service logs all operations with structured context:

// Successful operations _logger.LogInformation("Successfully uploaded {Key} to bucket {Bucket}", "uploads/file.pdf", "my-bucket"); // Retry attempts _logger.LogWarning("S3 operation retry {RetryCount}/{MaxRetries} after {Delay}. Error: SlowDown", 2, 3, "1s"); // Errors _logger.LogError("S3 error uploading {Key}: {ErrorCode} - {Message}", "uploads/file.pdf", "AccessDenied", "Insufficient permissions");

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🤝 Contributing

Contributions are welcome! Please open an issue or submit a pull request.

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📄 License

MIT License. See LICENSE for details.

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👤 Author

Ivan Paz

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🏢 Company

Acontplus