The Java application server is dead

Jiedao jdon 2021-05-04 02:18:47
java application server dead


This paper holds that Node.js The microservice architecture launched by us will completely subvert JavaEE Traditional application server concept ,Java The application server includes Tomcat JBoss Websphere Weblogic or Oracle Application server . The application server is Java EE or Servlet Containers .

We need an application server to deploy our application on each server , It's been a habit for years , But today we're going to ask , Why are we doing this ? Why do we have to pay for the application server ?

The PPT From the four aspects of application server analysis :

1. An application server is a container for multiple applications ?

2. The application server is the underlying infrastructure ?

3. Deployment of application server ?

4. Monitoring of application server ?

First , An application server is a container for multiple applications , The advantage of this is that you can pass through the application ClassLoader Isolation , They don't affect each other . Actually, it's just ClassLoader It's not enough to isolate the loading levels of classes ,CPU Memory Does the application system need to be isolated ? otherwise , If a stand-alone application is very expensive CPU, Or will it affect other applications . In particular, we will JMS and Web On the same server ,JMS It will consume a lot of resources .

therefore , Isolation is impossible , Even if JVM Become an operating system , Isolation won't be perfect either .Linux Operating systems are isolated from each other by processes , however CPU Memory is also shared .

So what does it really mean to deploy multiple applications in one application server ?JavaEE The application of multiple applications refers to a component Component Concept , Not at all App, Such as WAR EJB JAR etc. . Different components are made up of different Classloader load , isolated .

The following figure shows JavaEE Three concepts of :

application server --> App application ----> Multiple components

in other words , One application server corresponds to one App application , Not many App, It's multiple components , This is a JavaEE What application server really means . Multiple application servers can form a cluster .

secondly , The application server is the infrastructure , Provide some basic functionality , These functions include : Two transaction commit (2PC) Networks and threads and infrastructure API.

2PC It's a cross database transaction mechanism , Ensure the atomicity of complex operations , adopt JMS Distributed transaction can be realized . however 2PC There are the following problems : It reduces processing performance , No 100% reliable ,2PC It will also fail , There are limitations in distributed environments , For new technologies that cannot be used , Such as REST + 2PC?   NoSQL + 2PC? The biggest problem is NoSQL Critically , There's no expansibility scalability.

Network and thread facilities include database connection pool and Http Thread pool and so on ,JavaEE Of API Include EJB, CDI, JPA, JSF etc. , The real problem is : The version is tightly coupled with the application server version , So it can be applied App Heavily dependent on application servers , Until a new application server is released , Otherwise the new API Can't use ,API Version conflicts are on the rise .

These infrastructures can't cover the common application through , Additional library packages need to be added , Finally, the application server is replaced by the library package , The application can carry the library package for transplantation , It's more transplantable . therefore , The application server is the same as the library package , It should be just another part of the application , otherwise ...

Advocate application server independence , This results in each application server having its own infrastructure , For example, database connection pool Special configuration method , Even added their own additional library package to the application server , Finally, it leads to a dependency loop , application app And the application server depend on different versions of the same package , It's hard to coordinate .

Application server independence also leads to differences between servers , Even different versions of servers are different , As a result, our applications can not be deployed seamlessly to the servers of these different manufacturers .

in addition , Application servers are not a common infrastructure , The batch MapReduce Etc. does not provide , It's just one kind of infrastructure .

Last , Application server can provide the function of deploying application and monitoring running , But it's always about complex tools , For example, the deployment format has WAR, EAR, JAR Three , Deployment tools use Maven Etc script , Monitoring is based on JMX and SMNP There are a lot of tool families . In today's increasingly frequent deployment , Simple deployment is more important , At this time, the application server becomes a headache .

therefore , These characteristics of application server lead to all kinds of problems today , Do we have to continue to struggle like this ?

Today's demand for products is Continuous Delivery Under the pressure of continuous delivery , We need a simpler infrastructure , A simpler way to deploy .

Nowadays, microservice architecture is becoming more and more popular , It has the following characteristics :

•  Be able to build software based on service composition

•  Service means business   Like an order Order, Catalog Directory and other services

•  Services can be redeployed independently

•  Compared with traditional applications, they are deployed to the application server as a whole , Microservices can be deployed independently .

•  Between microservices REST Communications .

So our problem is : Do you want to install an application server for each microservice ? Very heavy .

The proposal of microservice architecture undoubtedly subverts the traditional concept of application server , Now we can abandon the application server , Do it :

Create a JAR file , It contains a main Class is used to start , There are optimized and customized Infrastructure Library packages, such as Http The server etc. .

Easy to deploy in terms of deployment , Because there's only one JAR package , Then there are some command line configurations , These are standard deployment tools , Monitoring tools are also standard , For example, based on REST URL Monitoring of , Log files, etc .

Now the technology is ready , Such as Java Of Spring Boot or Javascript Of Node.js.

banq notes : Application servers are usually Java Another name for middleware , The application server is dead , The middleware concept becomes lightweight , Responsible for scalability Scalable Some of the middleware in Cloud Computing Paas replace . Reference resources : Cloud computing Paas Five floors

版权声明
本文为[Jiedao jdon]所创,转载请带上原文链接,感谢
https://javamana.com/2021/05/20210504021734611i.html

  1. 【计算机网络 12(1),尚学堂马士兵Java视频教程
  2. 【程序猿历程,史上最全的Java面试题集锦在这里
  3. 【程序猿历程(1),Javaweb视频教程百度云
  4. Notes on MySQL 45 lectures (1-7)
  5. [computer network 12 (1), Shang Xuetang Ma soldier java video tutorial
  6. The most complete collection of Java interview questions in history is here
  7. [process of program ape (1), JavaWeb video tutorial, baidu cloud
  8. Notes on MySQL 45 lectures (1-7)
  9. 精进 Spring Boot 03:Spring Boot 的配置文件和配置管理,以及用三种方式读取配置文件
  10. Refined spring boot 03: spring boot configuration files and configuration management, and reading configuration files in three ways
  11. 精进 Spring Boot 03:Spring Boot 的配置文件和配置管理,以及用三种方式读取配置文件
  12. Refined spring boot 03: spring boot configuration files and configuration management, and reading configuration files in three ways
  13. 【递归,Java传智播客笔记
  14. [recursion, Java intelligence podcast notes
  15. [adhere to painting for 386 days] the beginning of spring of 24 solar terms
  16. K8S系列第八篇(Service、EndPoints以及高可用kubeadm部署)
  17. K8s Series Part 8 (service, endpoints and high availability kubeadm deployment)
  18. 【重识 HTML (3),350道Java面试真题分享
  19. 【重识 HTML (2),Java并发编程必会的多线程你竟然还不会
  20. 【重识 HTML (1),二本Java小菜鸟4面字节跳动被秒成渣渣
  21. [re recognize HTML (3) and share 350 real Java interview questions
  22. [re recognize HTML (2). Multithreading is a must for Java Concurrent Programming. How dare you not
  23. [re recognize HTML (1), two Java rookies' 4-sided bytes beat and become slag in seconds
  24. 造轮子系列之RPC 1:如何从零开始开发RPC框架
  25. RPC 1: how to develop RPC framework from scratch
  26. 造轮子系列之RPC 1:如何从零开始开发RPC框架
  27. RPC 1: how to develop RPC framework from scratch
  28. 一次性捋清楚吧,对乱糟糟的,Spring事务扩展机制
  29. 一文彻底弄懂如何选择抽象类还是接口,连续四年百度Java岗必问面试题
  30. Redis常用命令
  31. 一双拖鞋引发的血案,狂神说Java系列笔记
  32. 一、mysql基础安装
  33. 一位程序员的独白:尽管我一生坎坷,Java框架面试基础
  34. Clear it all at once. For the messy, spring transaction extension mechanism
  35. A thorough understanding of how to choose abstract classes or interfaces, baidu Java post must ask interview questions for four consecutive years
  36. Redis common commands
  37. A pair of slippers triggered the murder, crazy God said java series notes
  38. 1、 MySQL basic installation
  39. Monologue of a programmer: despite my ups and downs in my life, Java framework is the foundation of interview
  40. 【大厂面试】三面三问Spring循环依赖,请一定要把这篇看完(建议收藏)
  41. 一线互联网企业中,springboot入门项目
  42. 一篇文带你入门SSM框架Spring开发,帮你快速拿Offer
  43. 【面试资料】Java全集、微服务、大数据、数据结构与算法、机器学习知识最全总结,283页pdf
  44. 【leetcode刷题】24.数组中重复的数字——Java版
  45. 【leetcode刷题】23.对称二叉树——Java版
  46. 【leetcode刷题】22.二叉树的中序遍历——Java版
  47. 【leetcode刷题】21.三数之和——Java版
  48. 【leetcode刷题】20.最长回文子串——Java版
  49. 【leetcode刷题】19.回文链表——Java版
  50. 【leetcode刷题】18.反转链表——Java版
  51. 【leetcode刷题】17.相交链表——Java&python版
  52. 【leetcode刷题】16.环形链表——Java版
  53. 【leetcode刷题】15.汉明距离——Java版
  54. 【leetcode刷题】14.找到所有数组中消失的数字——Java版
  55. 【leetcode刷题】13.比特位计数——Java版
  56. oracle控制用户权限命令
  57. 三年Java开发,继阿里,鲁班二期Java架构师
  58. Oracle必须要启动的服务
  59. 万字长文!深入剖析HashMap,Java基础笔试题大全带答案
  60. 一问Kafka就心慌?我却凭着这份,图灵学院vip课程百度云