“Layers”和“Tiers”的区别是什么?


当前回答

我使用层来描述我的解决方案组件中的架构师或技术堆栈。通常在涉及网络或进程间通信时,我使用层对这些组件进行逻辑分组。

其他回答

我使用层来描述我的解决方案组件中的架构师或技术堆栈。通常在涉及网络或进程间通信时,我使用层对这些组件进行逻辑分组。

当你谈论表示、服务、数据、网络层时,你是在谈论层。 当你“分别部署它们”时,你谈论的是层。

Tiers是关于部署的。 这样说吧:我们有一个应用程序,它有一个用Angular创建的前端,它有一个像MongoDB一样的后端,还有一个在前端和后端之间交互的中间层。因此,当前端应用程序、数据库应用程序和中间层都单独部署时,我们称其为3层应用程序。

好处:如果我们将来需要扩展后端,我们只需要独立地扩展后端,而不需要扩展前端。

Logical layers are merely a way of organizing your code. Typical layers include Presentation, Business and Data – the same as the traditional 3-tier model. But when we’re talking about layers, we’re only talking about logical organization of code. In no way is it implied that these layers might run on different computers or in different processes on a single computer or even in a single process on a single computer. All we are doing is discussing a way of organizing a code into a set of layers defined by specific function. Physical tiers however, are only about where the code runs. Specifically, tiers are places where layers are deployed and where layers run. In other words, tiers are the physical deployment of layers.

来源:Rockford Lhotka,所有应用程序都应该是n层吗?

IBM的三层体系结构文章有一个章节专门讨论这个主题:

In discussions of three-tier architecture, layer is often used interchangeably – and mistakenly – for tier, as in 'presentation layer' or 'business logic layer.' They aren't the same. A 'layer' refers to a functional division of the software, but a 'tier' refers to a functional division of the software that runs on infrastructure separate from the other divisions. The Contacts app on your phone, for example, is a three-layer application, but a single-tier application, because all three layers run on your phone. The difference is important, because layers can't offer the same benefits as tiers.

Yes my dear friends said correctly. Layer is a logical partition of application whereas tier is physical partition of system tier partition is depends on layer partition. Just like an application execute on single machine but it follows 3 layered architecture, so we can say that layer architecture could be exist in a tier architecture. In simple term 3 layer architecture can implement in single machine then we can say that its is 1 tier architecture. If we implement each layer on separate machine then its called 3 tier architecture. A layer may also able to run several tier. In layer architecture related component to communicate to each other easily. Just like we follow given below architecture

表示层 业务逻辑层 数据访问层

客户端可以与“表示层”进行交互,但出于安全考虑,客户端可以访问“业务逻辑层”下一层的公共组件(如业务逻辑层的公共组件)。 问:为什么我们使用层结构? 因为如果我们实现了层结构,我们就能提高应用程序的效率

= = >安全

= = >可管理性

= = >可伸缩性

其他需求,如开发应用程序后,我们需要改变DBMS或修改业务逻辑等,那么这是必要的。

问:为什么我们要使用分层架构?

因为每一层的物理实现都提供了更好的效率,没有层架构我们就无法实现层架构。分离机实现分离 层和分离层是实现一个或多个层这就是我们使用它的原因。 它用于容错目的。 ==>易于维护。

简单的例子

就像银行开在一个房间里,员工在里面分类:

门房 现金的人 负责介绍银行方案的人 经理

它们都是系统的相关组件。

如果我们去银行贷款,首先是一个门卫微笑着开门 之后我们就去就近介绍所有贷款方案的人 我们去经理小屋,通过贷款。 在那之后,最后我们去收银台贷款。 这些是银行的层结构。

层级呢? 一家银行的分行开在一个城镇,接着又开在另一个城镇,接着又开在另一个城镇 但是每个分支的基本要求是什么呢

门房 现金的人 负责介绍银行方案的人 经理

层和层的概念完全一样。