Patterns

Routing Slip

The Routing Slip pattern facilitates the sequential passing of a request through a chain of responsibility. Each handler in the chain examines the request and either processes it or forwards it to the next handler. Unlike the Chain of Responsibility pattern, the order in which handlers process the request is …

Scheduler

behavioral concurrency

The Scheduler pattern provides a mechanism for executing tasks at specific times or after defined intervals. It decouples task execution from the task definition, allowing for flexible and dynamic scheduling of operations. A central scheduler component manages a queue of tasks, each associated with a time or trigger, …

Service-Oriented Architecture (SOA)

architectural enterprise integration distributed systems

Service-Oriented Architecture (SOA) is an architectural style that structures an application as a collection of loosely coupled services. These services communicate with each other, potentially over a network, using well-defined interfaces and protocols (typically HTTP, REST, or message queues). The goal of SOA is to …

Sharding

scalability architecture database

Sharding is a database architecture pattern used to horizontally partition a dataset across multiple machines (shards). This is typically done when a single database instance can no longer handle the growing volume of data or the increasing number of read/write operations. Each shard contains a subset of the total …

Shared-Nothing

architectural scalability distributed systems

The Shared-Nothing architecture is a distributed computing architecture where each node in the system has its own dedicated resources – CPU, memory, and disk – and does not share these resources with any other node. Nodes communicate with each other via a network, typically using message passing. This contrasts with …

Single Table Inheritance

behavioral ORM DDD

Single Table Inheritance is a strategy for representing a class hierarchy in a relational database using only one table for all classes in the hierarchy. A “type” column (or discriminator) is added to the table to indicate the specific class of each record. This approach simplifies querying and joins compared to other …

Snapshot

behavioral memory management

The Snapshot pattern captures the internal state of an object at a particular point in time, allowing it to be restored to that state later. This is achieved by creating a “snapshot” or “memento” of the object’s state, which is then stored by a separate “caretaker” object. The …

Space-Based Architecture

architectural distributed systems cloud

Space-Based Architecture is a distributed architectural pattern where application functionality is broken down into independently deployable services, often referred to as “spaces.” These spaces are designed to be loosely coupled, communicating primarily through well-defined APIs and asynchronous messaging. …

Specification

behavioral DDD

The Specification pattern encapsulates business rules in objects, allowing for dynamic combinations and reuse. It’s a way to separate complex logic concerning data from the objects that hold that data. This enables you to define a variety of rules, combine them, and then apply these rules to objects without directly …

State

behavioral OOA

The State pattern allows an object to alter its behavior when its internal state changes. This pattern avoids the use of large conditional statements (like if/else or switch) that often become unwieldy and difficult to maintain when dealing with complex state-dependent logic. Instead, each state is represented by a …