Web architecture design process

Catalog

One 、 Architecture evolution

Two 、 Design principles

3、 ... and 、 Essential tools

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One 、 Architecture evolution

1、 The initial set up

Framework based , Running on the Tomcat In the container . file 、 database 、 The application is on a server .

2、 Service separation

As the number of users increases , A single server cannot meet the load of the system , The application server and data server can be deployed separately , If possible, you can also deploy the file server separately .

3、 Reverse proxy

In order to improve the service processing capacity , We are Tomcat Add a proxy server in front of the container , such as Nginx、apache also . The user's request is sent to the reverse proxy , Then the reverse proxy forwards the request to the back-end server . Strictly speaking ,Nginx Belong to web The server , Generally deal with static html、css、js request , and Tomcat Belong to web Containers , Designed to handle JSP request , Of course Tomcat Also support html Of , It just didn't work Nginx All right .

4、 Dynamic and static separation

Based on the above Nginx Reverse proxy , We can also achieve   Dynamic and static separation , Static requests such as html、css、js Wait for the request to be given to Nginx Handle , Dynamic requests are distributed to the backend Tomcat Handle .Nginx Upgrade to 1.9.5+ Can be opened HTTP/2.0 Time , Accelerate website access . Of course , If the company doesn't need money , CDN It's also a good choice . 

5、 Service split

In this era when distributed microservices have become popular , In fact, we don't need to step on too many pits , It's easy to split . There are relatively mature technologies on the market , For example, Alibaba open source Dubbo( The official made it clear that the maintenance has begun ),Spring The family's SpringCloud, Of course, how to implement it , Both technology and business should be well controlled .

Microservices and lightweight communications ：

• Synchronous communication and asynchronous communication
• The remote invocation RPC
• REST
• Message queue

6、 Continuous integration deployment

After service split , With it comes continuous integration deployment , You may use the following tools ：Docker、Jenkins、Git、Maven. The basic topology is as follows ：

 

The evolution of the entire continuous integration platform architecture is shown in the figure below ：

 

7、 Service cluster

Linux Clusters are mainly divided into three categories ( High availability cluster , Load balancing cluster , Scientific computing cluster ). Actually , The load balancing cluster is the most common one we come into contact with in production .

（1） Load balancing implementation

• DNS Load balancing , General domain name registrants dns Server does not support
• Four layer load balancing (F5、LVS), Working in TCP Under the agreement
• Seven layer load balancing (Nginx、haproxy), Working in Http Under the agreement

（2） Distributed session

Everybody knows , Services are generally divided into stateful and stateless , And distributed sessoion For stateful Services .

8、 Read / write separation

MySql Master slave configuration , Read write separation and introduction of middleware , Open source MyCat, Ali's DRDS All good choices . If high availability is required , But there is no corresponding technical guarantee , It is recommended to use Alibaba cloud's RDS perhaps Redis Correlation database , Save time, effort and money .

9、 Cache optimization

The introduction of caching is nothing more than to reduce the pressure of back-end database services , Prevent it " Strike ". Common cache services are ,Ehcache、OsCache、MemCache、Redis, Of course, these are the mainstream cache technology implementation that can stand the test , especially Redis It has been widely used in distributed cluster services , And proved its superior performance .

10、 Message queue

1、 Asynchronous notification ： For example, SMS verification , E-mail verifies these non real-time feedback logical operations .

 

2、 Flow cutting ： It should be a common scenario in message queues , Generally, it is widely used in seckill or group robbery activities .

3、 Log processing ： Logs are essential in the system , But how to deal with the logs issued by Gao and is really a technical job , Carelessness may overwhelm the whole service . We often use open source logs in our work ELK, Why add one in the middle Kafka perhaps redis That's the reason ( The difference between an influx of people and a queue ).

4、 Message communication ： Point to point communication ( Individual to individual ) Or publish subscribe mode ( The chat room ).

11、 The log service

Mentioned in the message queue ELK Open source log component is a good choice for small and medium-sized start-ups .

12、 Security optimization

All these above , If there is no guarantee of safety, it may return to zero .

• Ali cloud, VPN Virtual private network and security group configuration
• If you build your own computer room , Configure the firewall security policy by yourself
• Related service access , such as Mysql、Redis、Solr If there are no special needs, try to use intranet access and set authentication
• Try to use a proxy server , Don't open too many ports
• https coordination HTTP/2.0 It's also a good choice

Two 、 Design principles

1、 High availability

• Load balancing （ Load balancing algorithm ）
• Reverse proxy
• Service isolation
• Service restriction
• service degradation （ Automatic graceful degradation ）
• Failover
• Time out to try again （ Agent timeout 、 Container timeout 、 Front end timeout 、 Middleware timeout 、 Database timeout 、NoSql Overtime ）
• Rollback mechanism （ Online rollback 、 Database version rollback 、 Transaction rollback ）

2、 High concurrency

• Client cache （ Reduce network bandwidth 、 Reduce server stress 、 Reduce network latency ）
• HTTP cache
• Multi level cache
• Distributed cache
• Connection pool
• Asynchronous concurrency

3、 Distributed transactions

• Two stage submission ( Strong consistency )
• Three stage commit ( Strong consistency )
• Message middleware ( Final consistency ), Recommend Ali's RocketMQ

4、 queue

• Task queue
• Message queue
• Request queue

5、 Database technology

• Master slave copy （ extensible 、 Available backups ）
• Read / write separation （ Improve query speed 、 Reduce IO bottleneck 、 High expansion ）
• Vertical expansion of monomer （ Separation of business 、 High expansion 、 High performance ）
• Horizontal expansion of monomer （ High expansion 、 High performance ）
• Data heterogeneity

6、 Network security

• SQL Inject
• XSS attack
• CSRF attack
• Denial of service （DoS,Denial　of　Service） attack

7、 Load balancing

• The Internet （ Global load balancing ,DNS polling 、CDN Network distribution ）
• Hardware （ Local load balancing , Load Balancer 、 Address translation gateway , Efficient but expensive ）
• Software （ Local load balancing ,Linux Virtual Server、Nginx、HAProxy）

 

3、 ... and 、 Essential tools

1、 operating system

Linux（ necessary ）、 Microsoft

2、 Load balancing

DNS、F5、LVS、Nginx、OpenResty、HAproxy、 Load balancing SLB（ Alibaba cloud ）

3、 Distributed framework

Dubbo、Motan、Spring Cloud

4、 database middleware

DRDS （ Alibaba cloud ）、Mycat、360Atlas

5、 Message queue

RabbitMQ、ZeroMQ、Redis、ActiveMQ、Kafka

6、 Registry Center

Zookeeper、Redis

7、 cache

Redis、Oscache、Memcache、Ehcache

8、 Integrated deployment

Docker、Jenkins、Git、Maven

9、 Storage

OSS、NFS、FastDFS、MogileFS

11、 database

MySql、Redis、MongoDB、PostgreSQL、Memcache、HBase

12、 The Internet

private network VPC、 Elastic public network IP、CDN

Reprint ：

WEB Architecture Design Overview - A hundred miles of Twilight - Blog Garden