System Architecture - chapter 2

system

collection of components organized to accomplish a specific function or set of functions. are man-made and may be configured with one or more of the following

system example

hardware, software, data, humans, processes procedures , facilities, Materials and naturally occurring entities

The system life cycle stages from

ISO/IEC TS 24748-1 are

systems lifecycle elements

concept ,development,production ,utilization ,Support ,retirement

Concept

need for the system is determined and evaluated. Requirements are determined and the conceptual design is created

Development

where a detailed design is built and evaluated. Prototypes, engineering and other specifications are created and reviewed

Production

where the system is manufactured, assembled, and integrated into its operational environment.

systems lifecycle elements 

Is a framework containing the processes, activities, and tasks involved in the development, operation, and maintenance of a software product, which spans the life of the system from the definition of its requirements to the termination of its use.

A life cycle model

blueprint that outlines all the steps and tasks needed to create, run, and keep a software product working well. It covers everything from figuring out what the software needs to do to when it's no longer used.

Architecting

is the process of planning, defining and expressing, documenting and maintaining the architecture of a system

Architecting

happens throughout the life cycle of a system

Architecture

of system fundamental concepts or properties of a system in its environment.

a legacy system

an old and a previous or outdated computer system computer system Hardware or Software that use and fulfills business needs

Legacy applications

written for old operating system or hardware platform.

Integrated Systems

Two or more (sub-systems) components are merged together into a single system with Different types of hardware may be integrated with other hardware.

Systems architecture

describes the components of the system and how they are organized.

Centralized Systems are Client-Server Systems

There is a central server that stores data and responds to requests for data from clients (devices) , The server responds to requests from clients , Business logic and presentation are deployed on the client

Distributed Systems

are Peer to Peer Systems (P2P) There are many nodes that are connected to one another, There is no central server. Data is distributed amongst the peers , Each peer can be both a client and a server , Can be complex to maintain

Software architecture

describes the components of the software and how they are organized within an application

Monolithic architecture

All components of the software such as the User Interface, Data Access Layer and the Business Logic are in one unit

Microservice Architecture

Several components or microservices are used in an application. Each microservice represents a business capability

Layered Architecture

Components are organized in layers such as Presentation layer, Processing/Logic layer and Data layer

Monolithic systems

is built as a single unit. It is a monolith – a single logical executable , built as a large system with a single code base and deployed as a single unit , Usually behind a load balancer.

Monolithic systems major components

a user interface ,business logic ,a data interface , a database.

Enterprise Applications

large and complex software that are used to integrate several functions of a business

Enterprise Applications three parts

database ,client-side user , server-side application which is the monolith

Microservices

a technique —a variant of the service-oriented architecture (SOA) structural style that arranges an application as a collection of loosely coupled services ,services are fine-grained, and the protocols are lightweight, are small, each running in their own process, using lightweight communication mechanisms ,

Microservices Applications (Apps)

are larger but still small, separate, runnable processes, using a share-nothing model that share many characteristics with microservices.

web service

software you can use online that follows certain rules to share data between different apps or systems. It’s like a collection of small, separate apps that you can easily find, use, and connect to over the internet, usually through the web.

The Web Services architecture describes three roles

service provider, service requester and service broker;

The Web Services architecture three basic operations

publish, find and bind.

XML

used to encode all communications to a web service.