Typical Architectural Styles

Typical Architectural Styles

1. Data flow

   • The general data flow style
     • Computational model The computational model of an architectural style is the overall mechanism that a system in the style works
     • The data flow style is characterised by viewing the system as a series of transformations on successive pieces of input data
     • Design vocabulary
       • Associated to each architectural style is a set of design vocabulary about the specific types of components and connectors that can be used in the systems
   • The pipe-and-filter sub-style
     • Computational model
       • The pipe-and-filter architectural style is a sub-type of data flow style
     • Design vocabulary
       • there are three important constraints on the components
         • Independence
         • Anonymity
         • Concurrency.
   • The batch sequential processing sub-style
     • Computational model
       • Batch sequential processing is also a sub-type of data flow architectural style
       • in the batch sequential style, components are independent
     • Design vocabulary
       • The computational components in a batch sequential processing architecture are often called processing steps or phases.
     • Structural pattern
       • Batch sequential processing architectures usually consist of a finite number of steps

2. Independent components

   • The general independent components style
     • Computational model
       • Independent component architecture consists of a number of components that communicate through messages
     • Design vocabulary
       • All components of a system in the independent component style must be executable
   • The event-based implicit invocation systems sub-style
     • Computational model
       • Individual components in an event-based implicit invocation system announce data
     • Design vocabulary
       • A component’s announcement of data is usually called publishing the data
     • Structural Pattern
       • systems usually contains a collection of events that it can raise and a collection of procedures
   • The communicating processes sub-style
     • Computational model
       • Processes communicate with each other, messages are passed to synchronize their executions
     • Design vocabulary
       • There are a number of different communication mechanisms that are provided by various operating systems and can be used by the system
     • Structural pattern
       • The general structure of communicating processes systems is a network of processes connected by communication channels

3. Call and return

   • The general call and return style
     • Computational model
       • A software system in call and return style is essentially decomposed into smaller pieces to deal with complexity and to help achieve modifiability.
     • Structural pattern
       • a system in the call and return style can have any topological structure that links subroutines by subroutine calls
   • The layered systems sub-style
     • Computational model
       • The main characteristic of the style is its way of organising subroutines into a simple topological structure
     • Structural pattern and design vocabulary
       • subroutines are organised into a number of groups, which are called layers
       • Each layer contains a collection of subroutines that provide services at a certain abstract level to the layer or layers above it
   • Data abstraction: the abstract data type and object-oriented sub-styles
     • Computation model
       • dynamic binding enables a variable to refer to objects of different classes
     • Structural pattern and design vocabulary
       • Managers are responsible for preserving the integrity of a resource