Amazon SQS Provider

The Amazon SQS provider offers enterprise-grade message queuing with advanced features like FIFO queues, dead letter queues, and long polling. It’s ideal for mission-critical applications requiring high reliability and throughput.

Installation

Install the Amazon SQS packages:

dotnet add package SimpleMessageBus.Publish.Amazon
dotnet add package SimpleMessageBus.Dispatch.Amazon

Basic Configuration

Publishing Configuration

Configure the publisher in your startup:

using SimpleMessageBus.Publish.Amazon.Extensions;

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddSimpleMessageBusAmazonSQSPublisher(options =>
{
    options.Region = "us-east-1";
    options.AccessKey = builder.Configuration["AWS:AccessKey"];
    options.SecretKey = builder.Configuration["AWS:SecretKey"];
    options.DefaultQueueName = "messages";
});

var app = builder.Build();

Dispatching Configuration

Configure the message dispatcher:

using SimpleMessageBus.Dispatch.Amazon.Extensions;

builder.Services.AddSimpleMessageBusAmazonSQSDispatcher(options =>
{
    options.Region = "us-east-1";
    options.AccessKey = builder.Configuration["AWS:AccessKey"];
    options.SecretKey = builder.Configuration["AWS:SecretKey"];
    options.DefaultQueueName = "messages";
    options.MaxConcurrentMessages = 20;
    options.WaitTimeSeconds = 20; // Long polling
});

Configuration Options

AmazonSQSOptions

Authentication Settings

public class AmazonSQSOptions
{
    // AWS Region
    public string Region { get; set; } = "us-east-1";
    
    // Authentication - choose one method
    public string AccessKey { get; set; }
    public string SecretKey { get; set; }
    public string SessionToken { get; set; } // For temporary credentials
    
    // Alternative: Use IAM roles (recommended for EC2/ECS)
    public bool UseInstanceProfile { get; set; } = false;
    
    // Alternative: Use specific profile
    public string ProfileName { get; set; }
    
    // Default queue name
    public string DefaultQueueName { get; set; } = "messages";
    
    // Queue URL prefix (optional)
    public string QueueUrlPrefix { get; set; }
}

Message Processing

public class AmazonSQSDispatcherOptions : AmazonSQSOptions
{
    // Maximum messages to retrieve per request (1-10)
    public int MaxNumberOfMessages { get; set; } = 10;
    
    // Long polling wait time (0-20 seconds)
    public int WaitTimeSeconds { get; set; } = 20;
    
    // Message visibility timeout (seconds)
    public int VisibilityTimeoutSeconds { get; set; } = 300;
    
    // Maximum concurrent message processing
    public int MaxConcurrentMessages { get; set; } = 20;
    
    // Enable dead letter queue handling
    public bool EnableDeadLetterQueue { get; set; } = true;
    
    // Dead letter queue suffix
    public string DeadLetterQueueSuffix { get; set; } = "-dlq";
    
    // Maximum delivery count before DLQ
    public int MaxDeliveryCount { get; set; } = 3;
}

Advanced Settings

public class AmazonSQSAdvancedOptions
{
    // Use FIFO queues for ordered processing
    public bool UseFifoQueues { get; set; } = false;
    
    // Message group ID for FIFO queues
    public string MessageGroupId { get; set; } = "default";
    
    // Enable content-based deduplication
    public bool ContentBasedDeduplication { get; set; } = true;
    
    // Custom SQS client configuration
    public AmazonSQSConfig SqsConfig { get; set; }
    
    // Message attributes to include
    public Dictionary<string, string> DefaultMessageAttributes { get; set; }
    
    // Custom queue name resolver
    public IQueueNameResolver QueueNameResolver { get; set; }
}

Authentication Methods

Access Keys (Development)

For development environments:

{
  "AWS": {
    "AccessKey": "AKIAIOSFODNN7EXAMPLE",
    "SecretKey": "wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY",
    "Region": "us-east-1"
  }
}

builder.Services.AddSimpleMessageBusAmazonSQSPublisher(options =>
{
    options.AccessKey = builder.Configuration["AWS:AccessKey"];
    options.SecretKey = builder.Configuration["AWS:SecretKey"];
    options.Region = builder.Configuration["AWS:Region"];
});

IAM Roles (Recommended for Production)

For EC2 instances, ECS tasks, or Lambda functions:

builder.Services.AddSimpleMessageBusAmazonSQSPublisher(options =>
{
    options.Region = "us-east-1";
    options.UseInstanceProfile = true; // Use attached IAM role
});

Named Profiles

Using AWS CLI profiles:

builder.Services.AddSimpleMessageBusAmazonSQSPublisher(options =>
{
    options.Region = "us-east-1";
    options.ProfileName = "production"; // Profile from ~/.aws/credentials
});

Temporary Credentials

For applications using AWS STS:

builder.Services.AddSimpleMessageBusAmazonSQSPublisher(options =>
{
    options.Region = "us-east-1";
    options.AccessKey = temporaryCredentials.AccessKey;
    options.SecretKey = temporaryCredentials.SecretKey;
    options.SessionToken = temporaryCredentials.SessionToken;
});

Queue Types

Standard Queues

Default queue type with high throughput:

builder.Services.AddSimpleMessageBusAmazonSQSPublisher(options =>
{
    options.DefaultQueueName = "messages";
    // Standard queue used by default
});

Characteristics:

Nearly unlimited throughput
At-least-once delivery
Best-effort ordering
Lower cost

FIFO Queues

For ordered message processing:

builder.Services.AddSimpleMessageBusAmazonSQSPublisher(options =>
{
    options.DefaultQueueName = "messages.fifo"; // Must end with .fifo
    options.UseFifoQueues = true;
    options.MessageGroupId = "order-processing";
    options.ContentBasedDeduplication = true;
});

Characteristics:

Exactly-once processing
Strict message ordering
3,000 messages/second with batching
Higher cost

Dead Letter Queue Configuration

Automatic DLQ Setup

SimpleMessageBus can automatically configure dead letter queues:

builder.Services.AddSimpleMessageBusAmazonSQSDispatcher(options =>
{
    options.EnableDeadLetterQueue = true;
    options.MaxDeliveryCount = 3;
    options.DeadLetterQueueSuffix = "-dlq";
});

Manual DLQ Configuration

Set up DLQ manually in AWS Console or with Infrastructure as Code:

{
  "QueueConfiguration": {
    "RedrivePolicy": {
      "deadLetterTargetArn": "arn:aws:sqs:us-east-1:123456789012:messages-dlq",
      "maxReceiveCount": 3
    }
  }
}

DLQ Message Processing

Handle messages from dead letter queue:

public class DeadLetterHandler : IMessageHandler<FailedMessage>
{
    private readonly ILogger<DeadLetterHandler> _logger;
    private readonly IEmailService _emailService;

    public async Task HandleAsync(FailedMessage message)
    {
        _logger.LogCritical("Message failed after max retries: {@Message}", message);
        
        // Alert operations team
        await _emailService.SendAlertAsync(
            "Dead Letter Queue Alert",
            $"Message {message.MessageId} failed processing after {message.AttemptCount} attempts"
        );
        
        // Store for manual investigation
        await StoreForInvestigation(message);
    }
}

Message Attributes and Metadata

Standard Message Attributes

SQS supports message attributes for filtering and routing:

public class OrderMessage : IMessage, IMetadataAware
{
    public string OrderId { get; set; }
    public decimal Amount { get; set; }
    
    public Dictionary<string, object> Metadata { get; set; } = new()
    {
        ["Priority"] = "High",
        ["Source"] = "WebApp",
        ["Version"] = "2.0"
    };
}

Custom Message Attributes

Add custom attributes during publishing:

public class CustomSQSPublisher : IMessagePublisher
{
    private readonly AmazonSQSMessagePublisher _basePublisher;

    public async Task PublishAsync<T>(T message) where T : IMessage
    {
        var envelope = new MessageEnvelope
        {
            Content = JsonSerializer.Serialize(message),
            MessageType = typeof(T).FullName,
            Timestamp = DateTime.UtcNow,
            Headers = new Dictionary<string, object>
            {
                ["Environment"] = Environment.GetEnvironmentVariable("ASPNETCORE_ENVIRONMENT"),
                ["MachineName"] = Environment.MachineName,
                ["ProcessId"] = Environment.ProcessId
            }
        };
        
        await _basePublisher.PublishAsync(envelope);
    }
}

Error Handling and Retry Strategies

Built-in Retry Logic

Configure automatic retries:

builder.Services.AddSimpleMessageBusAmazonSQSDispatcher(options =>
{
    options.VisibilityTimeoutSeconds = 300; // 5 minutes
    options.MaxDeliveryCount = 5; // Retry up to 5 times
});

Custom Error Handling

Implement sophisticated error handling:

public class RobustMessageHandler : IMessageHandler<OrderMessage>
{
    public async Task HandleAsync(OrderMessage message)
    {
        try
        {
            await ProcessOrder(message);
        }
        catch (ValidationException ex)
        {
            // Don't retry validation errors - send to DLQ immediately
            _logger.LogWarning(ex, "Validation error for order {OrderId}", message.OrderId);
            throw new PermanentFailureException("Validation failed", ex);
        }
        catch (HttpRequestException ex) when (IsTransientError(ex))
        {
            // Retry transient HTTP errors
            _logger.LogWarning(ex, "Transient error processing order {OrderId}", message.OrderId);
            throw; // Will be retried automatically
        }
        catch (Exception ex)
        {
            // Log unexpected errors
            _logger.LogError(ex, "Unexpected error processing order {OrderId}", message.OrderId);
            throw;
        }
    }

    private bool IsTransientError(HttpRequestException ex)
    {
        return ex.Message.Contains("timeout") || 
               ex.Message.Contains("connection") ||
               ex.Message.Contains("502") ||
               ex.Message.Contains("503");
    }
}

Monitoring and CloudWatch Integration

CloudWatch Metrics

SQS automatically publishes metrics to CloudWatch:

ApproximateNumberOfMessages
ApproximateNumberOfMessagesVisible
NumberOfMessagesSent
NumberOfMessagesReceived
NumberOfMessagesDeleted

Custom Application Metrics

Track application-specific metrics:

public class MetricsMessageHandler : IMessageHandler<OrderMessage>
{
    private readonly IMetrics _metrics;

    public async Task HandleAsync(OrderMessage message)
    {
        using var activity = Activity.StartActivity("ProcessOrder");
        activity?.SetTag("order.id", message.OrderId);
        
        var timer = Stopwatch.StartNew();
        
        try
        {
            await ProcessOrder(message);
            
            // Success metrics
            _metrics.Counter("orders.processed")
                   .WithTag("status", "success")
                   .Add(1);
                   
            _metrics.Histogram("order.processing.duration")
                   .WithTag("status", "success")
                   .Record(timer.ElapsedMilliseconds);
        }
        catch (Exception ex)
        {
            // Error metrics
            _metrics.Counter("orders.processed")
                   .WithTag("status", "error")
                   .WithTag("error.type", ex.GetType().Name)
                   .Add(1);
                   
            throw;
        }
    }
}

X-Ray Tracing

Enable AWS X-Ray for distributed tracing:

builder.Services.AddAWSXRayTracing();

public class TracingOrderHandler : IMessageHandler<OrderMessage>
{
    public async Task HandleAsync(OrderMessage message)
    {
        using var segment = AWSXRayRecorder.Instance.BeginSubsegment("ProcessOrder");
        
        segment.AddAnnotation("OrderId", message.OrderId);
        segment.AddMetadata("Order", message);
        
        try
        {
            await ProcessOrder(message);
            segment.AddAnnotation("Status", "Success");
        }
        catch (Exception ex)
        {
            segment.AddException(ex);
            segment.AddAnnotation("Status", "Error");
            throw;
        }
    }
}

Performance Optimization

Long Polling

Use long polling to reduce costs and latency:

builder.Services.AddSimpleMessageBusAmazonSQSDispatcher(options =>
{
    options.WaitTimeSeconds = 20; // Maximum long polling time
    options.MaxNumberOfMessages = 10; // Batch processing
});

Batch Operations

Process messages in batches:

public class BatchOrderProcessor : IMessageHandler<OrderMessage>
{
    private readonly List<OrderMessage> _batch = new();
    private readonly object _lock = new();

    public async Task HandleAsync(OrderMessage message)
    {
        bool shouldProcess;
        
        lock (_lock)
        {
            _batch.Add(message);
            shouldProcess = _batch.Count >= 10; // Process in batches of 10
        }

        if (shouldProcess)
        {
            List<OrderMessage> currentBatch;
            lock (_lock)
            {
                currentBatch = new List<OrderMessage>(_batch);
                _batch.Clear();
            }

            await ProcessBatch(currentBatch);
        }
    }

    private async Task ProcessBatch(List<OrderMessage> orders)
    {
        // Process multiple orders efficiently
        await _orderService.ProcessOrdersAsync(orders);
    }
}

Multiple Processors

Scale with multiple queue processors:

// Configure multiple processors for high throughput
for (int i = 0; i < Environment.ProcessorCount; i++)
{
    builder.Services.AddSimpleMessageBusAmazonSQSDispatcher($"processor-{i}", options =>
    {
        options.DefaultQueueName = "high-volume-messages";
        options.MaxConcurrentMessages = 10;
    });
}

Security Best Practices

IAM Policies

Minimal required permissions for publisher:

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": [
        "sqs:SendMessage",
        "sqs:GetQueueAttributes"
      ],
      "Resource": "arn:aws:sqs:us-east-1:123456789012:messages*"
    }
  ]
}

Minimal required permissions for dispatcher:

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": [
        "sqs:ReceiveMessage",
        "sqs:DeleteMessage",
        "sqs:ChangeMessageVisibility",
        "sqs:GetQueueAttributes"
      ],
      "Resource": "arn:aws:sqs:us-east-1:123456789012:messages*"
    }
  ]
}

VPC Endpoints

Use VPC endpoints for private communication:

builder.Services.AddSimpleMessageBusAmazonSQSPublisher(options =>
{
    options.SqsConfig = new AmazonSQSConfig
    {
        ServiceURL = "https://vpce-1234567-abcdefgh.sqs.us-east-1.vpce.amazonaws.com"
    };
});

Message Encryption

Enable server-side encryption:

// Configure queue with SSE-SQS (managed keys)
// Or SSE-KMS (customer managed keys)
// This is done at the queue level in AWS

Troubleshooting

Authentication Errors

Symptoms: AmazonServiceException with access deniedSolutions:

Verify IAM permissions
Check access key and secret key
Ensure correct region
Validate queue ARN format

// Test SQS connection
var sqs = new AmazonSQSClient(accessKey, secretKey, RegionEndpoint.USEast1);
var queues = await sqs.ListQueuesAsync();

Throttling Issues

Symptoms: AmazonServiceException with throttling errorsSolutions:

Implement exponential backoff
Reduce message rate
Use batch operations
Consider FIFO queue limits

options.RetryPolicy = new ExponentialBackoffRetryPolicy
{
    MaxRetries = 5,
    BaseDelay = TimeSpan.FromSeconds(1)
};

Message Size Limits

Symptoms: MessageTooLarge exceptionsSolutions:

SQS limit: 256 KB
Use S3 for large payloads
Reference S3 objects in messages

public class LargeDataMessage : IMessage
{
    public string S3Bucket { get; set; }
    public string S3Key { get; set; }
    public string MessageId { get; set; }
}

Complete Example

Here’s a complete working example with FIFO queue and DLQ:

// Program.cs
using SimpleMessageBus.Publish.Amazon.Extensions;
using SimpleMessageBus.Dispatch.Amazon.Extensions;

var builder = WebApplication.CreateBuilder(args);

// Configure Amazon SQS with FIFO queue
builder.Services.AddSimpleMessageBusAmazonSQSPublisher(options =>
{
    options.Region = "us-east-1";
    options.UseInstanceProfile = true; // Use IAM role
    options.DefaultQueueName = "orders.fifo";
    options.UseFifoQueues = true;
    options.MessageGroupId = "order-processing";
});

builder.Services.AddSimpleMessageBusAmazonSQSDispatcher(options =>
{
    options.Region = "us-east-1";
    options.UseInstanceProfile = true;
    options.DefaultQueueName = "orders.fifo";
    options.UseFifoQueues = true;
    options.EnableDeadLetterQueue = true;
    options.MaxDeliveryCount = 3;
    options.WaitTimeSeconds = 20; // Long polling
    options.MaxConcurrentMessages = 10;
});

// Register handlers
builder.Services.AddScoped<IMessageHandler<OrderCreatedMessage>, OrderCreatedHandler>();

var app = builder.Build();

// API endpoint
app.MapPost("/orders", async (CreateOrderRequest request, IMessagePublisher publisher) =>
{
    var orderId = Guid.NewGuid().ToString();
    
    await publisher.PublishAsync(new OrderCreatedMessage
    {
        OrderId = orderId,
        CustomerId = request.CustomerId,
        TotalAmount = request.TotalAmount,
        CreatedAt = DateTime.UtcNow
    });
    
    return Results.Ok(new { OrderId = orderId });
});

app.Run();

Next Steps

FIFO Queues

Learn about ordered message processing

Dead Letter Queues

Handle failed messages effectively

CloudWatch Monitoring

Monitor your SQS integration

Performance Tuning

Optimize for high throughput

​Installation

​Basic Configuration

​Publishing Configuration

​Dispatching Configuration

​Configuration Options

​AmazonSQSOptions

​Authentication Methods

​Access Keys (Development)

​IAM Roles (Recommended for Production)

​Named Profiles

​Temporary Credentials

​Queue Types

​Standard Queues

​FIFO Queues

​Dead Letter Queue Configuration

​Automatic DLQ Setup

​Manual DLQ Configuration

​DLQ Message Processing

​Message Attributes and Metadata

​Standard Message Attributes

​Custom Message Attributes

​Error Handling and Retry Strategies

​Built-in Retry Logic

​Custom Error Handling

​Monitoring and CloudWatch Integration

​CloudWatch Metrics

​Custom Application Metrics

​X-Ray Tracing

​Performance Optimization

​Long Polling

​Batch Operations

​Multiple Processors

​Security Best Practices

​IAM Policies

​VPC Endpoints

​Message Encryption

​Troubleshooting

​Complete Example

​Next Steps

FIFO Queues

Dead Letter Queues

CloudWatch Monitoring

Performance Tuning

Installation

Basic Configuration

Publishing Configuration

Dispatching Configuration

Configuration Options

AmazonSQSOptions

Authentication Methods

Access Keys (Development)

IAM Roles (Recommended for Production)

Named Profiles

Temporary Credentials

Queue Types

Standard Queues

FIFO Queues

Dead Letter Queue Configuration

Automatic DLQ Setup

Manual DLQ Configuration

DLQ Message Processing

Message Attributes and Metadata

Standard Message Attributes

Custom Message Attributes

Error Handling and Retry Strategies

Built-in Retry Logic

Custom Error Handling

Monitoring and CloudWatch Integration

CloudWatch Metrics

Custom Application Metrics

X-Ray Tracing

Performance Optimization

Long Polling

Batch Operations

Multiple Processors

Security Best Practices

IAM Policies

VPC Endpoints

Message Encryption

Troubleshooting

Complete Example

Next Steps