Module 9 operation

【 Business background 】

As an architect of an e-commerce startup , Responsible for the design  6.18  Design of big promotion second kill system , Your business model is as follows ：

1.  You choose the best-selling and highly praised products on major e-commerce platforms to sell , No more than... Per category  20  A commodity , At present, we have done  10  Categories ;

2.  This time  6.18  Second kill chose  1000  A power bank ,10  platform  iPhone 12  As a second kill commodity ;

3.  The normal daily life is about  100  Million users ;

4.  The boss asked to be foolproof .

【 Technical background 】

1.  The technical team takes  Java  Mainly , The microservice architecture has been implemented ;

2.  The main channels are self owned  App（ Include  iOS  and  Android） And WeChat applet , In order to promote the transformation of users into  App  user , Download only  App  To participate in the second kill ;

3.  At present, there are only single rooms .

【 Completion requirements 】

1.  Design a complete architecture , Such as storage 、 Load balancing 、 cache 、 High availability 、 Expandable etc ;

2.  about  10  Within the page  PPT, each page  PPT  Explain a design , Including architecture design and design reasons , There is no need to explain the alternatives in detail .

【 Tips 】

1.  Analysis and consideration should be comprehensive , But it doesn't mean that the architecture design should be comprehensive , If it is considered that some design points can not be done after analysis , Explain the reasons uniformly at the end of the operation ;

2.  If there is no thought , Please refer to the module  9  Of  IM  Case study ;

3.  If some information is not complete or detailed enough , You can make certain assumptions , But you can't fly in the sky , It is necessary to make a reasonable inference against the existing business background and technical background

Business scenario

Overall framework

1、 Daily life affects ： Secsha will generally be preheated and promoted , Daily life will be greater than usual , Estimated as weekdays  5  times , namely  500W;

2、 Impact on other businesses ： The main purpose of this second kill is

In order to promote the transformation of users into  App  user

, So the promotion is mainly in small programs and  app  Inside , The increase of newly registered users is not obvious , In addition to the second kill, the order growth will not be particularly exaggerated .

Functions mainly affected ： download  app、 Sign in 、 Browse products, etc ;

download  app  It is a one-time activity , Login status and product information can be found in  app  Cache for several days , Before the second kill  3  The sky is not on the shelves and the products are updated , The existing architecture can basically meet other functions caused by seckill ;

3、 seckill ： Secsha business is a temporary activity , In order to avoid affecting the function and complexity of normal business , The function of the second kill link （ It mainly includes browsing 、 stock 、 Place an order 、 Payment and other functions , Logistics does not belong to this link ）, You need to provide secsha micro services independently .

Storage architecture design

Storage performance evaluation

【 register 】

Millions a day ,40% Active users , The total number of users is estimated at  300  All around

【 Sign in 】

Millions a day , Log in and read user information every day  100  ten thousand

【 Check products 】

10  Species , Every kind of  20  A commodity . The probability of commodity information change is small , It can be stored as a static resource in  cdn.

【 Order information 】

Millions a day , Every user everyday  1  Order per order , Order information if  500K, Daily order volume  0.5*100*10000=50000M, about  50G.

【 Payment information 】

Payment information mainly depends on third-party platforms , The storage account and payment transaction information is estimated to be less than the order information

Storage architecture design

  The storage design is mysql Database master-slave design

Computing architecture design

Computing performance evaluation

【 register 】

Daily new registered users can ignore

【 Sign in 】

Millions a day , Because you can only participate in the description activity after logging in , such as  50% Of active users before describing the activity  30  Minutes login ,tps

=100w*0.5/(30*60)=278

【 Order information 】

Due to inventory and commodity type restrictions ,1010  goods  1s  Internal looting finished ,tps=1010, Pressure test can be prepared to support orders  1500tps

【 Payment information 】

Payment information mainly depends on third-party platforms , And payment will be made only after the order is placed successfully , Not to be considered

Load balancing of computing architecture

Use keepalive+nginx,nginx Solve the single point of failure problem

Cache design of computing architecture

Text and picture information of seckill products can be sent to  app  cache .web  The container mainly caches static resources . Seckill goods can be sold in advance according to the inventory quantity  redis  Elements are generated in the queue . Inventory quantity of goods on the page , User balance, etc. can also be put into  redis  Inside .

Extensible design

High availability design

Due to the small number of early visits , The running effect is unknown , Single room available , Availability depends on the stability of the machine room , Only one center in the same city , If there is time and cost in the later stage , The million day living architecture is best made into a city with two machine rooms and two activities