Open edX ArchitectureOpen edX 架构Open edX is a web-based platform for creating, delivering, and analyzing online courses. It is the software that powers edx.org and many other online education sites.Open edX是一个可以生成、发布、分析在线课程的基于web的平台。该平台为edx.org等其他在线教育网站提供软件框架。This page explains the current architecture of the platform at a high level, without getting into too many details. We also describe where we are actively working on making changes.本文主要概括性的描述了 Open edX现有技术架构，不包含更为细致的技术内容。同时，我们也描述了我们目前主要工作集中在何处。Technologies技术Almost all of the server-side code in Open edX is in Python, with Django as the web application framework, using Mako templates.平台服务端源代码主要基于Python编写，同时在Web应用层框架基于Django 框架下的Mako模版系统开发。The browser-side code is written primarily in JavaScript. Some of the code is written in CoffeeScript, and edX is working to replace that code with JavaScript. Parts of the client-side code use the Backbone.js framework, and edX is moving more of the codebase to use that framework.系统前端主要基于JAVAScript编写。一些前端代码基于CoffeeScript编写，我们 目前也正在致力于将CoffeScript部分用Backbone.js框架进行重写，同时计划将 更多的代码库用Backbone.js进行替换。Open EdX uses Sass and the Bourbon framework for CSS code.Open edX使用Sass和Bourbon框架编写CSS代码。11-COW DlMEhTiy (Oni 阿_L-iQl an时L_L Gridg* BuB EEA Hfl-KcrrDiH. JCHiU AJL.Wsric-rra Ranin血 ricerF(KrJmSI POium I-. -E)LH&LW 踌 L)31图1.1 Open edX -CMS-LMS系统技术架构图Components组件There are a handful of major components in the Open edX platform. Where possible, these communicate using stable, documented APIs.这里介绍Open edX平台几大主要组件，和一些必要的已经稳定的功能API接口。Select the diagram to the right to view a larger image of the components of Open edX.图1.1画出了 Open edX平台的主要组件构成。Learning Management System (LMS)学习管理系统 The LMS is the most visible part of Open edX. Students take courses using the LMS. The LMS also provides instructor dashboards.学习管理系统是Open edX平台面向用户可见的部分。学习者通过LMS系统进 行学习。同时，LMS系统也向授课教师提供操作界面。The LMS uses a number of data stores. Courses are stored in Mongo, with videos served from YouTube or Amazon S3. Per-student data is stored in MySQL.LMS系统使用了一定数量的数据存储。课程存储在Mongo数据库中，视频源主 要存放在YouTube和亚马逊云存储中，每个学习者的信息存在MySQL数据库 中。As students move through courses and interact with them, events are published to the analytics pipeline for collection, analysis, and reporting.学习者直接学习课程的过程主要通过以上数据库进行记录，同时记录了发布事 件、数据分析管道收集、分析和报告等功能。Work is underway to enable the LMS to be an LTI provider so that Open edX courseware can be embedded into other learning environments.LMS系统作为学习工具交换提供方底层系统，将Open edX平台的课件内容嵌入 到学习环境中。Studio工作室组件Studio is the course authoring environment. Course teams use it to create and update courses.Studio writes its courses to the same Mongo database that the LMS uses.工作室组件式面向作者的应用环境。课程开发团队运用工作室组织机构创建、更 新课程内容。工作室组件和LMS系统使用同一个Mongo数据库存储课程数据。Course Browsing课程浏览组件Open edX provides a simple front page for browsing courses. The edx.org site has a separate home page and course discovery site that is not open source.Open edX平台提供简洁的前端页面用于浏览课程。Edx.org网站的主页和课程发 现网站不是开源的。Course Structure课程结构组件Open edX courses are composed of units called XBlocks. Anyone can write new types of XBlocks, allowing educators and technologists to extend the set of components for their courses.Open edX平台利用XBlocks作为课程的组织单元。任何人可以编写新的XBlocks 该框架为教育者和技术专家提供可扩展的组件方式去开发他们的课程。The edX Platform also still contains several XModules, the precursors to XBlocks. EdX is working to rewrite the existing XModules as XBlocks and remove XModules from our codebase.Open edX平台也存在一些XModules代码，XModules是XBlocks的前期版本。 我们也在组件的重写代码将原有的XModules代码改写为XBlocks。In addition to XBlocks, there are a few ways to extend courseware behavior:有以下几个途径去扩展课程：The LMS is an LTI tool consumer. Course authors can embed LTI tools to integrate other learning tools into an Open edX course.LMS系统是学习工具交互工具。课程开发者可以使用其他类型的学习交 互工具嵌入到Open edX平台课程中。Problems can use embedded Python code to either present the problem or assess the students responInstructor-written Python code is executed in a secure environment called CodeJail.问题可以以Python脚本嵌入的方式去展现问题或者为学习者提供反馈。 指导者写好的Python脚本可以在CodeJail环境下安全执行。JavaScript components can be integrated using JS Input.JavaScript组件可以利用JS Input集成。Courses can be exported and imported using Open Learning XML (OLX), an XML-based format for courses.课程可以通过OLX xml格式导入导出。Discussions课程讨论组件Course discussions use a separate server called the Comments Service. Discussions are one of the few non-Python components, written in Ruby using the Sinatra framework. The LMS uses an API provided by the Comments Service to integrate discussions into the students course experience.课程讨论组件被安置在名叫Comments Service服务器中。讨论组件是平台中极少 不使用Python语言开发的组件。该组件使用了 Ruby语言的Sinatra框架编写。 LMS系统使用API调用，将课程讨论功能嵌入到课程系统。The forums include a notifier process that sends students notifications about updates in to