Project architecture evolution

Monomer architecture ：

There are not many users , The project is also unstable

advantage ：

• The monomer architecture is simple , Low development cost of small projects .
• The project is deployed on a node , Maintenance is also easier .

shortcoming ：

• All functions are integrated in one project , Not easy to develop and maintain for large projects .
• Project modules are tightly coupled , Low single point fault tolerance .
• It is impossible to optimize and expand different modules .

Set up the cluster ：

Improve project stability , Increased concurrency tolerance , One of the servers is down , No problem .

But there are some new problems after setting up the cluster , for example （ Including but not just these three ）：

• How user requests are distributed to different servers , So as to relieve the pressure of the increase in the number of users .
• After the user logs in successfully , Data sharing .
• When the amount of data is huge , If you go directly to the database to query , slowly , How to improve query efficiency

Can pass Nginx【 Solve the request allocation problem 】、Redis【 Solve data sharing and caching problems 】、Elasticsearch【 Solve the data query problem 】 Technology , Solve the above problems .

Vertical architecture ：

The so-called vertical architecture is to split an original application into several unrelated applications , To improve efficiency .

For example, we split a system into user modules 、 Order module 、 Commodity module , Once the order module is accessed too much , Just add the order module node .

Distributed architecture ：

Projects are generally divided into controller、service、dao Three layers , In fact, the hardest hit areas that cause the program to slow down may be service perhaps dao layer , The cluster is built for all three layers , The effect is not very good , So it began to evolve into a distributed architecture .

Distributed architecture issues ：

problem 1： After using the distributed architecture , The direct communication between servers is synchronous , On some functions that are not core business, I certainly hope it is asynchronous communication , In order to realize the asynchronous communication between servers, there is MQ【RabbitMQ、RocketMQ etc. 】

problem 2： Because there are many modules , And the number of module clusters increases , It will cause other modules to need to maintain various ip Address and other information , The maintainability of the project is extremely low , Extremely high coupling , And it can not achieve the effect of load balancing

There are also technologies that can help us manage service information 【Nacos perhaps Eureka】,【ribbon】 It can help us realize the load balancing of services

problem 3： If there is a problem with the order module , As long as the content of this module is involved, it cannot be used , It may cause the thread pool provided by the service to be exhausted , Nor can it give user-friendly tips

So there is 【Sentinel 】 Technology to solve

problem 4： A large amount of data will make the database unable to store all the contents or respond very slowly when querying data , In the case of high user concurrency , The database is also unbearable .

So it can be based on 【mycat】 Implement database division by database and table

Microservice architecture

Microservice architecture is split again on the basis of distributed architecture , Make each service do only one thing .

problem ： Too many modules increase the operation and maintenance cost

solve ： use 【docker】 Containerization technology helps us manage