On digital currency M0
The digital currency of the central bank is DCEP
the name of the digital currency developed by the central bank is DCEP (digital currency electronic payment). DC is digital currency. EP is electronic payment. Payment transmits digital things through a certain way, not paper currency. Therefore, electronic payment itself has the attribute of digital currency
The characteristics of digital currency are: low transaction cost; Fast trading speed; Highly anonymous
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Application of digital currency
I. fast, economic and safe payment and settlement
cross border payment helps RMB internationalization. In 2015, the settlement volume of cross-border payment involving current account is about 8 trillion yuan. To accelerate the internationalization of RMB, cross-border payment and settlement procts and solutions with low cost, high efficiency and low risk are needed
At present, there are still a lot of repetitive human work in the bank's electronic loan process and processing process, and as the basic support of loan issuance, many of the collateral has the situation of false pricing or multiple or even no collateral. We can consider using digital currency to price and track bank collateral:3. Bill finance and supply chain finance
in recent years, various bill market businesses based on commercial bills have grown rapidly, and bill financing procts have become a hot area of Internet financing. However, about 70% of the current bill businesses in China are still paper transactions, Supply chain finance is also highly dependent on labor costs
reference materials
network digital currency
Generally, the excellent digital currencies are mostly imported procts, such as bitcoin, Leyte coin, ether coin and so on. However, the domestic Yuanbao coin, Ruitai coin, bitcoin and the tokens of different crowdfunding projects of European crowdfunding are excellent digital currencies
< H2 > development materials
digital currency (English: digital currency) is an alternative currency in the form of electronic currency. At present, no central bank of any government has indicated that it will issue digital currency, and digital currency does not have to have a benchmark currency and a central bank
it is different from the virtual currency in the virtual world, because it can be used for real goods and services transactions, not limited to online games. The early digital currency (digital gold currency) is a form of electronic currency named after the weight of gold. Today's digital currency, such as bitcoin, lightcoin and ppcoin, is an electronic currency created, issued and circulated by check sum cryptography
China: actively and steadily promote the implementation of the research on the central bank's digital currency
as early as 2014, the central bank set up a special research group on the issue of legal digital currency to demonstrate the feasibility of the central bank's issue of legal digital currency< On October 28, 2019, Huang Qifan, vice president of China Center for international economic exchange, said: "the people's Bank of China has studied DC / EP for five or six years, and I think it has become mature. The people's Bank of China is likely to be the first central bank in the world to launch a digital currency. "
on November 28, fan Yifei, vice governor of the people's Bank of China, said at the forum that at present, the central bank's legal digital currency DC / EP has basically completed the top-level design, standard formulation, function research and development, joint debugging and testing under the premise of adhering to double-layer delivery, M0 substitution and controllable anonymity. In the next step, we will follow the principle of steady, safe and controllable, reasonably select the pilot verification area, scene and service scope, continuously optimize and enrich the DC / EP functions, and steadily promote the introction and application of digital legal tender< European Central Bank: exploring the form and possibility of CBDC. 'we are analyzing what form CBDC may take in order to achieve its potential purpose and mitigate its potential negative impact on monetary stability and financial intermediation,' Mr. kindos said. On the stable coin, Mr jindos said that it was very uncertain whether the stable coin could deliver on its promise, and it was clear that it could bring risks to consumers and the financial system. So it is understandable that authorities around the world are calling for regulatory stability.
Yang Xu, senior solution architect of Alibaba cloud, is the chief architect of the world's largest hybrid cloud. Four years ago, he began to be the technical director of double 11 Alibaba cloud, responsible for building the world's largest hybrid cloud structure, and implementing the "double 11" e-commerce business and technology scenarios on alicloud, And ensure that the hybrid cloud can meet the shopping needs of global customers on the day of double 11<
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recently, everyone is talking about microservices. As more and more online businesses need to provide more concurrent scale-up and scale out capabilities, microservices do provide better distributed service solutions
microservices are no stranger. It's easy to understand microservices when you know SOA. You can regard microservices as SOA without ESB. ESB is the bus in SOA enterprise service architecture, while micro service is a decentralized distributed software architecture. I think the biggest difference lies in the original design intention:
SOA is to maximize the reusability of complex system code
while micro service is to maximize decoupling, Different business systems can even be the communication between different languages
there is no optimal architecture, only the most appropriate architecture. All the system design principles should take solving business problems as the ultimate goal, and the technical sentiment architecture divorced from the actual business will often bring a big hole to the system. The premise of all problems is to find out how much business we are facing today and what the growth trend is. Moreover, the process of solving high concurrency must be a graal process< The whole system evolution is divided into three stages:
x-axis, horizontal expansion stage. The application server is continuously expanded horizontally through load balancing server. The most important problem of horizontal expansion is to pay attention to how to keep session and session synchronization between servers, Users can't be aware when switching between different servers. The bottleneck of DB is the number of connections, IOPs and so on
the z-axis is to split the database, and the difficulty has reached a higher level. Sharding's basic idea is to divide a database into horizontal segmentation and vertical segmentation. Horizontal segmentation is relatively simple, one master and many followers, and many masters can do it. According to the needs of business, we need to pay attention to the relationship between primary keys when designing multi master segmentation, To solve the first mock exam problem, the vertical resolution is more complex. It usually involves the transformation of the logic of the architecture. It needs to introce middleware to manage the data source. When the vertical resolution is split, the tables close to each other (such as the same mole) can be split on a library or split by hash. Thus, the original database is divided into a queue which can be expanded infinitely like a matrix
Y-axis extension, and finally function decomposition, which is what we call microservice segmentation. Microservice splitting divides giant applications into groups of different services according to their functional moles. Taobao's system also experienced this process in those years. Through the wucaishi project, we split the single war package into today's buyer, seller center, trading system, etc
two or three things you need to know before introcing microservices:
1. As the cost increases, the introction of microservice architecture needs to split the original single system. After 1 to 100, the deployment of multiple services will increase the cost
2. Solving the consistency problem of distributed transactions
in the past, a single system has many advantages, and one SQL solves all the business logic, Microservices need to involve multiple system calls to complete a task. The uncertainty of the network between systems brings a lot of uncertainty to the result. For example, today's Taobao system needs to call hundreds of systems to complete a transaction order. How to ensure the reliability of the system and the final consistency of core data such as money is something we need to understand at the beginning of design, Most of them are implemented with the help of middleware
3. The logic design principle of microservices
with the continuous splitting of microservices and the iterative development of business, chaotic calls are likely to occur between systems, so the top-level design of microservices is particularly important, and architects need to understand the architecture model of microservices. The core design idea is how to layer services and reuse services. Services are distributed by layers. The upper services are packaged by the lower services. The lower services are responsible for atomic operations. The upper services are responsible for the business composition and arrangement of the lower services. We must understand the business. Micro service splitting is not a simple system composition, Once again, we must understand the business, otherwise there will be a lot of cross calls in the upper services, and the system complexity will rise exponentially. A good microservice architect must be a business architect. Based on the business strategy, microservice design trilogy, Follow the bottom-up design principle:
atomic service
first confirm the most basic business and the most dimensional atomic service. Atomic service definition is the function that everyone will maximize reuse. It needs closed-loop operation in the application. There is no branching logic across other services. It eliminates the call to other services and has its own independent data storage, As the lowest level service abstract existence, take Taobao as an example, seller data, seller data and order data belong to the most basic atomic service
service composition
in a business scenario, a function needs to span multiple atomic services to complete an action. Composition service is to abstract business logic into independent domains. Domains need to be isolated. Service composition will use multiple atomic services to complete business logic. For example, Taobao trading platform will call user, commodity, inventory and other systems
business choreography
the outermost layer is the user oriented business process. A proctized business process needs to logically choreograph the composite service to complete the final business result. The choreography service can be completely automated, and the specific SOP definition can be completed through the workflow engine, It is also significant to improve the automation process of enterprise application. For example, Taobao's "double 11" campaign realizes the logic of marketing activities by reusing the service composition
4. The complexity of operation and maintenance management is improved
microservices increase the number of applications, and link integration, testing, and deployment become new challenges. The problem solved by the previous war package needs to be completed through multi application publishing. The dependency between services at the time of publishing will lead to the unavailability of functions, and the dependency at the testing stage may make the use cases unable to run, These will be new issues to be considered and supported by platform tools. At present, Ali uses aone procts to ensure continuous integrated delivery from daily delivery to pre delivery to online delivery.