architecture

LinkedIn, Allen Holub

🪕 1. The Software Architect

UML: Unified Modeling Language, xmind

📑 Modern Architects

Agile Software Development (incremental design)

An Agile Architect (Servant 仆人 Leader) duty:

• teaching, coaching, coordinating

• main design responsibility: assures coherence(连贯性) across the system (reviews work, makes suggestions, helps refine process)

• guide, direction, collaboratively, make decisions

• Researching is part of job: programmers, conferences, vendors, operations

Daily work

• 9:00am meeting: ba, po, tech leader, scrum master, developers, ui/ux designers, db experts, testers, devops,

• 10:30am: Sprint Review

• 2:00pm: techincal understanding and availibility, trade-offs(权衡), innerconnections, etc(open-source research, license, dependencies, firewall setup, backup, searching engines, kubernates, i18n, cloud/api integration)

• meetup, work collaboratively

Good Architecture

• Simplicity

• Maintainability

• Testability

📑 Thinking Architecturally

• Conway's law: Architecutre and organization structure

• Story: a description of the user's work - a story touches every piece of the system

• Agile Incremental Designs: Customer, Stories, Technology

• DDD (Domain-Driven Design): The structure of your code should map to the structure of the problem domain.( =300x200)

• ubiquitous language(无处不在的语言) in DDD: universal notation, such as SKU=order item,

• JIRA, Sticky notes

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📑 System vs. enterprise architecture (EA)

Broad architectural patterns

📑 monolith 整体式

• homogeneous (同质) structure, heterogeneous (异质), Protocol Aware Heterogeneous Interoperability (协议感知异构互操作性)

• N-Tier

📑 Microkernel(plugin) architecture

• Isolation prevents big ball-of-mud dependencies

• Plugins are small and easy to write, debug, and maintain

📑 Message-based architectures

• producer, broker, consumer

• Pub/Sub Model

• messaging infrastructure

📑 Microservices and miniservices

• Small (few hundred lines of source codes)

• independently deployable

• fully autonomous(自主性)

• distributed

• Highly observable

• Modeled around business concepts

📑 Reactive and choreographed(编排) systems

🪕 2. Microservices Foundations

• Decompositions, System Decompositions

• polyglot (多种语言) development support

• All communications over ReST/GraphQL

• The stages of evolution in modern software servicce architectures, from oldest to most modern are: N-Tier, SOA, Microservices

• BPEL (Business Process Execution Language) is an XML-based language that allows Web services in a service-oriented architecture (SOA) to interconnect and share data. Programmers use BPEL to define how a business process that involves web services will be executed.

• ACID: atomic, consitent, isolated, durable transaction

• BASE

🪕 3. Node.js: Design Patterns

📑 Creational Patterns

• singleton

• prototype

• factory

• builder

  class Person {
      constructor(builder) {
          this.name = name;
          this.isEmployee = builder.isEmployee;
          this.shoppingList = builder.shoppingList || [];
      }
      toString() {
          return JSON.stringify(this);
      }
  }
  class PersonBuilder {
      constructor(name) {
          this.name = name;
      }
      makeEmployee() {
          this.isEmployee = true;
          return this;
      }
      build() {
          return new Person(this);
      }
  }
  const bill = new PersonBuilder("Bill").makeEmployee().makePartTime().build();
  console.log(bill.toString());

📑 Structural Patterns

• adapter: 兼容不同环境，比如 browser 环境和 nodejs 环境的兼容。

• proxy

• composite 综合

• decorator

See github/jxjwilliam/my-package

📑 Behaviral Patterns

• command

• iterator

• observer

• strategy

See node-js-design-patterns

🪕 4. Software Architecture Patterns

📑 Design Patterns vs. Architecture Patterns (higher level)

📑 Categories of patterns (3)

• Application Landscape Patterns

  • Monolith

  • N-tier (BusinessTier, DataTier, PresentationTier, ...)

  • Service-oriented

  • Microservices

  • Serverless

  • Peer-to-peer (discoverable)

• Application Streucture Patterns

  • Layered

  • Microkernel

  • Command Query Responsibility Segregation (CQRS)

  • Event sourcing

  • Command Query Responsibilityy Segregation and event souring combined

• User Interface Patterns

  • Model-view-controller(MVC)

  • Model-view-presenter (MVP)

  • Model-view-viewmodel (MVVM)

📑 Application Landscape Patterns

• SOA: Service-Oriented Architecture

• Microservices

  • Docker, containers

  • No logic-heavy enterprise serivce bus

  • Teams run multiple services independently

  • Each service is a business activity

  • Loosely coupled and easily scalable, reliability, designed to handle failures

• Serverless

  • Backend as a Service

  • Function as a Service

  • Cold Start

  • AWS cloud

• Peer-to-Peer

  • Share resources

📑 Application Structure Patterns

• Layered

  • Easy to organize

• Microkernel: Plugin Pattern, flexibility, separate

  • Taskk scheduler

  • Workflow

  • Data processing

  • Browser

  • Graphic designer

📑 UI Patterns

MVC, MVP, MVVM Similarities:

• Decoupling view and model

• Extra component in between

• Increased testability

• Web: MVC; Desktop: MVP; Morden/Mobile: MVVM