12-Factor与微服务

       为了构建分布式微服务程序，能够部署到所有云服务，Heroku工程师总结所有云原生应用程序的12要素：

• 1.基准代码 Single codebase: The application must have one codebase, tracked in revision control for every application (read: microservice) that can be deployed multiple times (development, test, staging, and production environments). Two microservices do not share the same codebase. This model allows the flexibility to change and deploy services without impacting other parts of the application.
  
  
  
• 2.依赖 Dependencies: The application must explicitly declare its code dependencies and add them to the application or microservice. The dependencies are packaged as part of the microservice JAR/WAR file. This helps isolate dependencies across microservices and reduce any side effects through multiple versions of the same JAR.

• 3.配置 Config: The application configuration data is moved out of the application or microservice and externalized through a configuration management tool. The application or microservice will pick up the configuration based on the environment in which it is running, allowing the same deployment unit to be propagated across the environments.
  
  
  
• 4.后端服务 Backing services: All external resources, access should be an addressable URL. For example, SMTP URL, database URL, service HTTP URL, queue URL, and TCP URL. This allows URLs to be externalized to the config and managed for every environment.

• 5.构建，发布，运行 Build, release, and run: The entire process of building, releasing, and running is treated as three separate steps. This means that, as part of the build, the application is built as an immutable entity. This immutable entity will pick the relevant configuration to run the process based on the environment (development, testing, staging, or production).
  
  
  
• 6.进程 Processes: The microservice is built on and follows the shared-nothing model. This means the services are stateless and the state is externalized to either a cache or a data store. This allows seamless scalability and allows load balance or proxy to send requests to any of the instances of the service.

• 7.端口绑定 Port binding: The microservice is built within a container. The service will export and bind all its interfaces through ports (including HTTP).
  
  
  
• 8.并发 Concurrency: The microservice process is scaled out, meaning that, to handle increased traffic, more microservice processes are added to the environment. Within the microservice process, one can make use of the reactive model to optimize the resource utilization.

• 9.易处理Disposability: The idea is to build a microservice as immutable with a single responsibility to, in turn, maximize robustness with faster boot-up times. Immutability also lends to the service disposability.

• 10.环境等价Dev/prod parity: The environments across the application life cycle—DEV, TEST, STAGING, and PROD—are kept as similar as possible to avoid any surprises later.

• 11.日志Logs: Within the immutable microservice instance, the logs generated as part of the service processing are candidates for state. These logs should be treated as event streams and pushed out to a log aggregator infrastructure.
  
  
• 12.管理进程 Admin processes: The microservice instances are long-running processes that continue unless they are killed or replaced with newer versions. All other admin and management tasks are treated as one-off processes: Applications that follow the 12 factors make no assumptions about the external environment, allowing them to be deployed on any cloud provider platform. This allows the same set of tools/processes/scripts to be run across environments and deploy distributed microservices applications in a consistent manner.
  
  

12-Factor 为构建如下的 SaaS 应用提供了方法论：

使用标准化流程自动配置，从而使新的开发者花费最少的学习成本加入这个项目。

和操作系统之间尽可能的划清界限，在各个系统中提供最大的可移植性。

适合部署在现代的云计算平台，从而在服务器和系统管理方面节省资源。

将开发环境和生产环境的差异降至最低，并使用持续交付实施敏捷开发。

可以在工具、架构和开发流程不发生明显变化的前提下实现扩展。

适用于任意语言和后端服务（数据库、消息队列、缓存等）开发的应用程序。

－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－

今天先到这儿，希望对您技术领导力， 企业管理，系统架构设计与评估，团队管理, 项目管理, 产品管理,团队建设 有参考作用 , 您可能感兴趣的文章:
前端性能核对表Checklist-2018
大型电商互联网性能优化案例
国际化环境下系统架构演化
微服务架构设计
视频直播平台的系统架构演化
微服务与Docker介绍
Docker与CI持续集成/CD
互联网电商购物车架构演变案例
互联网业务场景下消息队列架构
互联网高效研发团队管理演进之一
消息系统架构设计演进
互联网电商搜索架构演化之一
企业信息化与软件工程的迷思
企业项目化管理介绍
软件项目成功之要素
人际沟通风格介绍一
精益IT组织与分享式领导
学习型组织与企业
企业创新文化与等级观念
组织目标与个人目标
初创公司人才招聘与管理
人才公司环境与企业文化
企业文化、团队文化与知识共享
高效能的团队建设
项目管理沟通计划
构建高效的研发与自动化运维
某大型电商云平台实践
互联网数据库架构设计思路
IT基础架构规划方案一(网络系统规划)
餐饮行业解决方案之客户分析流程
餐饮行业解决方案之采购战略制定与实施流程
餐饮行业解决方案之业务设计流程
供应链需求调研CheckList
企业应用之性能实时度量系统演变

如有想了解更多软件设计与架构, 系统IT,企业信息化, 团队管理 资讯，请关注我的微信订阅号：

作者：Petter Liu
出处：http://www.cnblogs.com/wintersun/
本文版权归作者和博客园共有，欢迎转载，但未经作者同意必须保留此段声明，且在文章页面明显位置给出原文连接，否则保留追究法律责任的权利。
该文章也同时发布在我的独立博客中-Petter Liu Blog。