Knowledge points related to system architecture 1

Mass effect tree ： Identify quality attributes and sort , Mainly including performance 、 Usability 、 Modifiable property 、 Four aspects of security .​

 

​ System architecture risk ： Potential in architecture design 、 Hidden dangers of problematic architectural decisions .

Sensitive points ： In order to achieve a specific quality attribute , The characteristics of one or more system components .

Trade off ： Affect multiple quality attributes , It is also a system attribute of sensitive points for multiple quality attributes .

Risk point ： It refers to the potential in the architecture design 、 Hidden dangers caused by problematic architecture decisions .

Non risk point ： It refers to the concerns of architectural decisions that do not cause potential problems in architectural design .

 

ATAM The main process of architecture evaluation method ：

Description and introduction stage ： describe ATAM Method , Describe business motivation , Describe the architecture

Investigation and analysis stage ： Determine the architectural approach , Generate quality attribute utility tree , Analysis architecture method

Testing phase ： Discuss scenarios and rank scenarios , Analysis architecture method

The final stage ： Describe the evaluation results

​DSSA features ：

（1） A strictly defined problem domain or solution domain

（2） It's universal , So that it can be used for the development of a specific application in the field

（3） An appropriate degree of abstraction of the entire domain

（4） Have a fixed in this field , Typical reusable elements in the development process

DSSA Main activities ：

（1） Domain analysis

（2） Domain design

（3） Domain realization

DSSA role ：

（1） Domain expert

（2） Domain analyst

（3） Domain designers

（4） Domain implementer

​ Multi - core refers to the integration of two or more complete computing engines in one processor （ kernel ）. A multi-core processor is a single chip （ Also known as silicon core ）, It can be directly inserted into a single processor socket , But the operating system will use all relevant resources , Each of its execution cores is treated as a separate logical processor . By dividing tasks between multiple execution cores , Multi core processors can perform more tasks in a specific clock cycle .

Multithreading refers to the technology of concurrent execution of multiple threads from software or hardware . Computers with multithreading capability can execute more than one thread at a time due to hardware support , Further improve the overall treatment performance .

​ Parallel is when two or more events occur at the same time . Parallelism results from the existence of multiple （ set ） Hardware resources , Such as multi-core CPU.

Concurrency means that two or more events occur within the same event interval . From a microscopic point of view , Or serial . As single CPU System .

If a system supports two or more actions at the same time , So this system is a concurrent system . If a system supports two or more actions at the same time , So this system is a parallel system

​ As the name suggests, microservices are very small services , It's an architectural model , Promote the division of a single application into a small set of services , Services coordinate with each other 、 Cooperate with each other , Provide the ultimate value for users . Each service runs in its own process , Services communicate with each other through lightweight communication mechanism ,（ Usually based on HTTP Agreed RESTFful API）. Each service is built around a specific business , And can be independently deployed to the production environment , In addition, try to avoid the same 、 Centralized service management mechanism , For a specific service , Should be based on the business context , Choose the right language 、 Tools to build it .

Microservices are characterized by ： Small and specialized, easy and alone . Small is relative to the granularity of the service ; fine ： Fine granularity ; specially ： Focus on one thing ; light ： Lightweight communication mechanism . pine ： Loosely coupled . single ： Strong independence 、 Independent deployment .

Advantages of microservices ：

（1） Technology heterogeneity

（2） bouncy

（3） Extensibility

（4） Automatic deployment

（5） Match the organization

（6） Composability between services

（7） Optimization of alternatives

Disadvantages of microservices ：

（1） The complexity of distributed system is high

（2） The cost of development, operation and maintenance is high

​（3） May require too much operation

（4） Need to improve DevOps Application skills

（5） It is difficult to diagnose the fault , Distributed deployment tracking is more complex than single architecture