在网上看到很多这样的文章,有的是复制同一个人的,而有的答案和概念都不太一样。请教下大神,能简单明了的说一下他们之间的区别吗
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在网上看到很多这样的文章,有的是复制同一个人的,而有的答案和概念都不太一样。请教下大神,能简单明了的说一下他们之间的区别吗
就软件系统来说。分布式指的是你的软件系统可以通过某些手段让各自独立的部分协作起来。这些独立的部分可以是真正独立的,也可以是虽然可以独立运行,但无法构成一个完整系统的,但一般指的是后者。分布的目的有很多,比如说为了分散计算的压力,也可能是为了松散的组件式系统便于扩展。分布式的软件系统模型也有很多,比如早期的EJB,现在的SOA,也有使用消息系统的,比如rabbitMQ,比较有名的有openstack。各种大数据软件都是分布式的,比如Hadoop,spark。他们都有自己的分布模型,做特定的事情。
web相关的软件都是分布的,一部分运行在浏览器里,一部分运行在服务器上。一般来说,数据库系统都是分布的。其实现代的软件大多数都已经是分布式的了,我们使用分布式系统已经很久了。
集群这个概念在软件相关的领域里面指的往往是一种部署的方式。分布式的软件一般都可以支持集群部署,比如数据库。使用集群的目的一般都是为了分散计算的压力。集群一般都是可以伸缩的,甚至可以根据一些策略自动的伸缩。
参考:分布式系统 概念与设计
实名反对@junze,不能到别的文章里拿过来就回到!!!
关于分布式,集群,负载均衡的概念,这两天刚好我也在看。
sf里http://segmentfault.com/q/1010000003052403
这个问题里已经回答的很好了,题主去看下
=========================================
集群:
班级大扫除,每个学生都会被老师调度来负责清理不同的地方。
张三擦黑板,李四摸桌子,王五擦风扇
一不小心王五被电死了,不能再擦风扇了,老师再分配赵六顶上。
一个学生代表一台主机,一个班级就是一个集群,老师就是负载均衡器
概念:是一个团体,要有一个负载均衡器
分布式:
操场大扫除,分给了甲班和乙班来共同清扫(共同处理一个任务)。
甲乙两个班级就是分布式的处理。
甲乙两个班级,也可以由老师分配不同的学生清扫某一小块。
这就是说分布式的处理节点可以是一个集群
概念:每个节点可以分布在不同的地方
简单说,分布式是以缩短单个任务的执行时间来提升效率的,而集群则是通过提高单位时间内执行的任务数来提升效率。
例如:
如果一个任务由10个子任务组成,每个子任务单独执行需1小时,则在一台服务器上执行改任务需10小时。
采用分布式方案,提供10台服务器,每台服务器只负责处理一个子任务,不考虑子任务间的依赖关系,执行完这个任务只需一个小时。(这种工作模式的一个典型代表就是Hadoop的Map/Reduce分布式计算模型)
而采用集群方案,同样提供10台服务器,每台服务器都能独立处理这个任务。假设有10个任务同时到达,10个服务器将同时工作,10小后,10个任务同时完成,这样,整身来看,还是1小时内完成一个任务!
我们一般说分布式远程调用,这样一看分布式是不是和远程调用有关系啦,比如A系统需要调用B系统上的某个服务,这就属于分布式。而如果B系统的请求量很大,一台机器处理不过来,这时就需要部署多个B系统来处理,这就是集群。
个人理解,希望不会误导了你。
"分布式"不一定指硬件, 可以指一种协作的方式
"集群"一般有明确的所属
DNS是个分布式系统, 我们不会说全球的DNS服务器是一个集群

What’s still popular is the ease of use, flexibility and a strong ecosystem. 1) Ease of use and simple syntax make it the first choice for beginners. 2) Closely integrated with web development, excellent interaction with HTTP requests and database. 3) The huge ecosystem provides a wealth of tools and libraries. 4) Active community and open source nature adapts them to new needs and technology trends.

PHP and Python are both high-level programming languages that are widely used in web development, data processing and automation tasks. 1.PHP is often used to build dynamic websites and content management systems, while Python is often used to build web frameworks and data science. 2.PHP uses echo to output content, Python uses print. 3. Both support object-oriented programming, but the syntax and keywords are different. 4. PHP supports weak type conversion, while Python is more stringent. 5. PHP performance optimization includes using OPcache and asynchronous programming, while Python uses cProfile and asynchronous programming.

PHP is mainly procedural programming, but also supports object-oriented programming (OOP); Python supports a variety of paradigms, including OOP, functional and procedural programming. PHP is suitable for web development, and Python is suitable for a variety of applications such as data analysis and machine learning.

PHP originated in 1994 and was developed by RasmusLerdorf. It was originally used to track website visitors and gradually evolved into a server-side scripting language and was widely used in web development. Python was developed by Guidovan Rossum in the late 1980s and was first released in 1991. It emphasizes code readability and simplicity, and is suitable for scientific computing, data analysis and other fields.

PHP is suitable for web development and rapid prototyping, and Python is suitable for data science and machine learning. 1.PHP is used for dynamic web development, with simple syntax and suitable for rapid development. 2. Python has concise syntax, is suitable for multiple fields, and has a strong library ecosystem.

PHP remains important in the modernization process because it supports a large number of websites and applications and adapts to development needs through frameworks. 1.PHP7 improves performance and introduces new features. 2. Modern frameworks such as Laravel, Symfony and CodeIgniter simplify development and improve code quality. 3. Performance optimization and best practices further improve application efficiency.

PHPhassignificantlyimpactedwebdevelopmentandextendsbeyondit.1)ItpowersmajorplatformslikeWordPressandexcelsindatabaseinteractions.2)PHP'sadaptabilityallowsittoscaleforlargeapplicationsusingframeworkslikeLaravel.3)Beyondweb,PHPisusedincommand-linescrip

PHP type prompts to improve code quality and readability. 1) Scalar type tips: Since PHP7.0, basic data types are allowed to be specified in function parameters, such as int, float, etc. 2) Return type prompt: Ensure the consistency of the function return value type. 3) Union type prompt: Since PHP8.0, multiple types are allowed to be specified in function parameters or return values. 4) Nullable type prompt: Allows to include null values and handle functions that may return null values.


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