Architecture

Understanding Internet Protocols: HTTP, HTTPS, TCP, UDP, and More Websites and applications communicate using different protocols, which are standardized methods for transferring data over a network. These protocols define how data is sent, received, and interpreted between systems. Below, we explore the most widely used protocols and their key features. HTTP (Hypertext Transfer Protocol) HTTP is the original protocol used for web communication. It enables the transfer of hypertext documents and allows users to interact with websites. ...

Updated Implementation Using System.Text.Json using System; using System.Text.Json; using System.Text.Json.Serialization; public abstract class MessageEnvelope<T> { // Properties remain immutable public string EventType { get; private init; } public string SourceService { get; private init; } public DateTime Timestamp { get; private init; } public Guid TraceId { get; private init; } public T Payload { get; private init; } // Private constructor for builder use only private MessageEnvelope() { } public static Builder CreateBuilder() => new Builder(); // Serialization to JSON public string ToJson() { var options = new JsonSerializerOptions { WriteIndented = true // Makes the output JSON easier to read }; return JsonSerializer.Serialize(this, options); } // Deserialization from JSON public static MessageEnvelope<T> FromJson(string json) { var options = new JsonSerializerOptions { PropertyNameCaseInsensitive = true // Handles case differences in JSON properties }; return JsonSerializer.Deserialize<ConcreteMessageEnvelope>(json, options); } // Concrete implementation example for proper deserialization private class ConcreteMessageEnvelope : MessageEnvelope<T> { } public class Builder { private readonly MessageEnvelope<T> _envelope = new ConcreteMessageEnvelope(); public Builder WithEventType(string eventType) { _envelope.EventType = eventType; return this; } public Builder WithSourceService(string sourceService) { _envelope.SourceService = sourceService; return this; } public Builder WithPayload(T payload) { _envelope.Payload = payload; return this; } public Builder WithTimestamp(DateTime timestamp) { _envelope.Timestamp = timestamp; return this; } public Builder WithTraceId(Guid traceId) { _envelope.TraceId = traceId; return this; } public MessageEnvelope<T> Build() { _envelope.Timestamp = _envelope.Timestamp == default ? DateTime.UtcNow : _envelope.Timestamp; _envelope.TraceId = _envelope.TraceId == default ? Guid.NewGuid() : _envelope.TraceId; return _envelope; } } } Example Usage 1. Serialize a MessageEnvelope to JSON var envelope = MessageEnvelope<Reservation> .CreateBuilder() .WithEventType("ReservationExpiry") .WithSourceService("ReservationService") .WithPayload(new Reservation { ReservationId = "res-001", SlotId = "slot-123", ExpiryTime = DateTime.UtcNow }) .Build(); string serialized = envelope.ToJson(); Console.WriteLine($"Serialized Envelope:\n{serialized}"); 2. Deserialize a JSON String to MessageEnvelope string json = "{\"EventType\":\"ReservationExpiry\",\"SourceService\":\"ReservationService\",\"Timestamp\":\"2025-03-25T17:00:00Z\",\"TraceId\":\"8a1db2c2-ec3e-45f7-a3eb-bd9dfb351245\",\"Payload\":{\"ReservationId\":\"res-001\",\"SlotId\":\"slot-123\",\"ExpiryTime\":\"2025-03-25T17:00:00Z\"}}"; var deserializedEnvelope = MessageEnvelope<Reservation>.FromJson(json); Console.WriteLine($"Deserialized EventType: {deserializedEnvelope.EventType}"); Console.WriteLine($"Deserialized Reservation ID: {deserializedEnvelope.Payload.ReservationId}"); Benefits of Serialization Portability: You can transmit envelopes as JSON over APIs, message brokers, or store them in databases. Interoperability: Many systems can parse JSON, making serialized envelopes easy to integrate across platforms. Flexibility: Deserialization lets you reconstruct envelopes when receiving messages. Advantages of System.Text.Json Performance: Faster than Newtonsoft.Json, especially for large-scale applications. Built-in Support: No need for external dependencies; it’s natively part of .NET Core and .NET 5+. Configuration Options: Flexible JSON options like camel casing, case insensitivity, and indented formatting.

Implementing the Clock-Bound Wait Pattern in C# The Clock-Bound Wait pattern is a critical technique in distributed systems to ensure consistency across nodes. Here are some C# code examples that demonstrate this pattern, using a simple distributed system where each node synchronizes its clock before performing read and write operations. 1. Determine Maximum Clock Offset Define a Clock class to determine the maximum clock offset and get the synchronized time. ...

Here’s an example implementation of the Inbox-Outbox pattern in C# using ASP.NET Core and Entity Framework Core. Inbox Pattern Example Inbox Entity: Define an entity to represent the inbox table in the database. public class Inbox { public long Id { get; set; } public string Message { get; set; } public bool Processed { get; set; } public DateTime ReceivedAt { get; set; } } Inbox Repository: Create a repository to interact with the inbox table. public interface IInboxRepository { Task<List<Inbox>> GetUnprocessedMessagesAsync(); Task SaveAsync(Inbox inbox); } public class InboxRepository : IInboxRepository { private readonly ApplicationDbContext _context; public InboxRepository(ApplicationDbContext context) { _context = context; } public async Task<List<Inbox>> GetUnprocessedMessagesAsync() { return await _context.Inboxes.Where(i => !i.Processed).ToListAsync(); } public async Task SaveAsync(Inbox inbox) { _context.Inboxes.Update(inbox); await _context.SaveChangesAsync(); } } Inbox Service: Implement a service to process the inbox messages. public class InboxService { private readonly IInboxRepository _inboxRepository; public InboxService(IInboxRepository inboxRepository) { _inboxRepository = inboxRepository; } public async Task ProcessInboxMessagesAsync() { var inboxMessages = await _inboxRepository.GetUnprocessedMessagesAsync(); foreach (var inbox in inboxMessages) { // Process the message inbox.Processed = true; await _inboxRepository.SaveAsync(inbox); } } } Outbox Pattern Example Outbox Entity: Define an entity to represent the outbox table in the database. public class Outbox { public long Id { get; set; } public string Message { get; set; } public bool Sent { get; set; } public DateTime CreatedAt { get; set; } } Outbox Repository: Create a repository to interact with the outbox table. public interface IOutboxRepository { Task<List<Outbox>> GetUnsentMessagesAsync(); Task SaveAsync(Outbox outbox); } public class OutboxRepository : IOutboxRepository { private readonly ApplicationDbContext _context; public OutboxRepository(ApplicationDbContext context) { _context = context; } public async Task<List<Outbox>> GetUnsentMessagesAsync() { return await _context.Outboxes.Where(o => !o.Sent).ToListAsync(); } public async Task SaveAsync(Outbox outbox) { _context.Outboxes.Update(outbox); await _context.SaveChangesAsync(); } } Outbox Service: Implement a service to send the outbox messages. public class OutboxService { private readonly IOutboxRepository _outboxRepository; public OutboxService(IOutboxRepository outboxRepository) { _outboxRepository = outboxRepository; } public async Task ProcessOutboxMessagesAsync() { var outboxMessages = await _outboxRepository.GetUnsentMessagesAsync(); foreach (var outbox in outboxMessages) { // Send the message outbox.Sent = true; await _outboxRepository.SaveAsync(outbox); } } } Integration You can use a hosted service to periodically call the inbox and outbox service methods to process the messages. ...

Industry Applications of the Clock-Bound Wait Pattern The Clock-Bound Wait pattern is a vital mechanism used in distributed systems to ensure data consistency, accurate ordering, and reliable operations across different nodes. Here are some specific industry examples where this pattern is applied: 1. Financial Services Scenario: In banking and financial services, ensuring the consistency of transactions across distributed systems is crucial. Example: A banking system that processes transactions across multiple branches uses the Clock-Bound Wait pattern to ensure that all transactions are ordered correctly. This prevents issues like double-spending or inconsistent account balances. ...

Practical Applications of the Clock-Bound Wait Pattern The Clock-Bound Wait pattern is crucial in distributed systems to ensure data consistency, event ordering, and reliable operations across different nodes. Here are some practical applications: Distributed Databases Scenarios: Consistency: Ensuring that data written to different nodes is ordered correctly to maintain strong consistency. Read/Write Operations: When a write operation occurs, waiting for the clock to synchronize ensures that subsequent read operations fetch the correct data version. Examples: ...

Practical Applications of the Clock-Bound Wait Pattern The Clock-Bound Wait pattern is crucial in distributed systems to ensure data consistency, event ordering, and reliable operations across different nodes. Here are some practical applications: CloudEvents CloudEvents is a specification designed to provide a consistent and standardized way to describe event data across different systems. The main goal of CloudEvents is to ensure interoperability between cloud services, platforms, and applications by defining a common event format. ...

Practical Applications of the Inbox-Outbox Pattern Here is a simple example of an outbox pattern implementation in C#. This example demonstrates how to create an outbox table, write messages to it, and process the messages to ensure reliable delivery. Database Schema First, create an OutboxMessages table in your database: CREATE TABLE OutboxMessages ( Id UNIQUEIDENTIFIER PRIMARY KEY, EventType NVARCHAR(256), Source NVARCHAR(256), Time DATETIMEOFFSET, DataContentType NVARCHAR(256), Data NVARCHAR(MAX), Processed BIT DEFAULT 0 ); OutboxMessage Class Next, create a class to represent the outbox message: ...

The Inbox-Outbox Pattern: Ensuring Reliable Messaging in Microservices The inbox-outbox pattern is a design pattern used in microservice architecture to ensure reliable message delivery and data consistency between services. Here’s a brief overview of each pattern: Inbox Pattern Purpose: Ensures that a message was received successfully at least once. How it works: When an application receives data, it persists this data to an inbox table in a database. Another application, process, or service can then read from the inbox table and use the data to perform an operation. This operation can be retried upon failure until it is completed successfully. Outbox Pattern Purpose: Ensures that a message was sent successfully at least once. How it works: When an application needs to send data, it persists this data to an outbox table in a database. Another application or process can then read from the outbox table and use the data to perform an operation. This operation can also be retried upon failure until it is completed successfully. These patterns are particularly useful in distributed systems where services need to communicate reliably and maintain data consistency despite potential failures or network issues. ...

Understanding the Clock-Bound Wait Pattern in Distributed Systems The Clock-Bound Wait pattern is a critical technique used in distributed systems to handle the uncertainty in time across cluster nodes. This pattern ensures that values can be correctly ordered across cluster nodes before reading and writing values, maintaining consistency and reliability. Problem In a distributed system, different nodes may have slightly different clock times. This can lead to inconsistencies when reading and writing values. For example, if two nodes have different clock times, they might read or write different versions of the same value, leading to confusion and inconsistency. ...