Blockchain synchronization

1.

blockchain is a term in the field of information technology. In essence, it is a shared database. The data or information stored in it is characterized by "unforgeability", "trace in the whole process", "traceability", "openness and transparency" and "collective maintenance". Based on these characteristics, blockchain technology has laid a solid "trust" foundation, created a reliable "cooperation" mechanism, and has broad application prospects

on January 10, 2019, the state Internet Information Office issued the regulations on the management of blockchain information services. In October 24, 2019, ring the eighteenth collective learning of the Central Political Bureau, general secretary Xi Jinping stressed that "block chain as an important breakthrough in core technology and independent innovation", "accelerating the development of block chain technology and instrial innovation". "Blockchain" has entered the public field of vision and become the focus of social attention

on December 2, 2019, the word was selected into the top ten catchwords of "biting words" in 2019

extended data:

Application of blockchain Finance:

since 2016, the major financial giants have also carried out blockchain innovation projects to explore the possibility of applying blockchain Technology in various financial scenarios. In particular, Puyin group took the lead in creating a "blockchain +" standard digital currency

standard digital currency refers to the process of assets identification, evaluation, right confirmation and insurance completed by a third party organization, which is written into the blockchain through careful digital algorithm to form the standard corresponding relationship between assets and digital currency, which is called standard digital currency

in order to realize the great leap forward development of blockchain finance, promote the new development of China's economy, accelerate the circulation of global assets, and realize the dream of rejuvenation that has been struggling for generations, Puyin group will hold the Guiyang strategic development ceremony of Puyin blockchain finance in Guizhou on December 9, 2016

the meeting will discuss the realization of digital circulation of assets by blockchain, the financial transaction mode of blockchain, and the application of blockchain services and social public instry. This conference will mark the beginning of the application of blockchain finance and the change and development of the new financial ecology

on June 1, 2020, Xinhua news agency was authorized to broadcast the "overall plan for the construction of Hainan free trade port" issued by the CPC Central Committee and the State Council, which will "actively participate in the formulation of international rules for cross-border data flow, and establish standards and rules for data rights confirmation, data trading, data security and blockchain finance" as one of the key tasks of Hainan free trade port before 2035

2.

From the perspective of technology and architecture, I will tell you my understanding of blockchain in common language

what is blockchain? In a word, blockchain is a storage system. To be more specific, blockchain is a distributed storage system without an administrator and each node has all the data

What are the common storage systems like

first, how to ensure high availability

the common storage system usually uses "rendancy" to solve the problem of high availability. As shown in the figure above, if the data can be copied into several copies and rendant to multiple places, high availability can be guaranteed. The data in one place is hung, and there is data in other places. For example, the master-slave cluster of MySQL is the same principle, and the raid of disk is also the same principle

two points need to be emphasized in this place are: data rendancy often leads to consistency problems

1. For example, in the master-slave cluster of MySQL, there is actually a delay in reading and writing, which means there is a inconsistency in reading and writing in a short period of time. This is a side effect of data rendancy

The second point is that data rendancy often reces the efficiency of writing, because data synchronization also consumes resources. If you add two slave libraries, the write efficiency will be affected. The common storage system is to use rendancy to ensure the high availability of data

so the second question, ordinary storage system, can write more

the answer is yes, for example, take this graph as an example:

in fact, MySQL can do a master-slave synchronization of al masters, master-slave synchronization of al masters, two nodes can be written at the same time. If you want to do a multi room multi live data center, in fact, multi room multi live data synchronization. What we should emphasize here is that multi-point writing often leads to the consistency problem of writing conflicts. Take MySQL as an example, suppose that the attribute of a table is self incrementing ID, then the data in the database is 1234 now. If one of the nodes writes and inserts a piece of data, it may become 5, and then these 5 pieces of data are synchronized to another master node, Before synchronization, if another write node inserts a piece of data, a piece of data with self incrementing ID of 5 will be generated. Then, after the generation, synchronize to another node, and the synchronized data will conflict with the two local 5's after it arrives, which will lead to synchronization failure and write consistency conflict. This problem will occur in the case of multi-point writing

how to ensure consistency in multi-point writing

the reform "Swan class" gives you more technical work

3. Blockchain mainly solves the trust and security problems of transactions, so it proposes four technological innovations to solve this problem:
(1) distributed ledger, that is, transaction bookkeeping is completed by multiple nodes distributed in different places, and each node records complete accounts, so they can participate in monitoring the legitimacy of transactions, At the same time, they can testify together
different from traditional distributed storage, the uniqueness of distributed storage of blockchain is mainly reflected in two aspects: one is that each node of blockchain stores complete data according to block chain structure, while traditional distributed storage generally stores data in multiple copies according to certain rules. Second, the storage of each node in the blockchain is independent and has the same status, which relies on the consensus mechanism to ensure the consistency of storage, while the traditional distributed storage generally synchronizes data from the central node to other backup nodes[ 8]
no single node can record the account data separately, so as to avoid the possibility that a single bookkeeper is controlled or bribed to record false accounts. In theory, unless all the nodes are destroyed, the accounts will not be lost, so as to ensure the security of the account data
(2) asymmetric encryption and authorization technology, the transaction information stored on the blockchain is public, but the account identity information is highly encrypted, which can only be accessed under the authorization of the data owner, thus ensuring the data security and personal privacy
(3) consensus mechanism is how to reach a consensus among all accounting nodes to determine the validity of a record, which is not only a means of identification, but also a means of preventing tampering. Blockchain proposes four different consensus mechanisms, which are suitable for different application scenarios and achieve a balance between efficiency and security
the consensus mechanism of blockchain has the characteristics of "the minority is subordinate to the majority" and "everyone is equal", in which "the minority is subordinate to the majority" does not completely refer to the number of nodes, but also can be the computing power, the number of shares or other characteristics that can be compared by computers“ "Everyone is equal" means that when the nodes meet the conditions, all nodes have the right to put forward the consensus results first, and then directly recognized by other nodes, and finally may become the final consensus results. Taking bitcoin as an example, the workload proof is adopted. Only when more than 51% of the accounting nodes in the whole network are controlled can a nonexistent record be forged. When there are enough nodes in the blockchain, this is basically impossible, thus eliminating the possibility of fraud.
(4) smart contract, which is based on these trusted and tamperable data, can automatically execute some pre-defined rules and terms. Take insurance as an example. If everyone's information (including medical information and risk occurrence information) is true and reliable, it is easy to carry out automatic claim settlement in some standardized insurance procts

4. First of all, we need to know exactly what both are before we can combine them

blockchain, which appeared in front of you when bitcoin was born a few years ago, is essentially a distributed data account book. We can see blockchain technology as an underlying code system in the Internet, which is decentralized, open, transparent, anonymous, user-friendly and user-friendly It can't be tampered with. Blockchain basically solves most of the trust problems in the weak trust environment, and has a wide range of applications. It can be combined with almost all fields, and even change the proction relationship of our three proction factors
the Internet of things, literally means "the network connecting things", its core is actually based on the data communication between the Internet and offline sensor devices. The Internet of things can be said to be the proct of the Internet extending offline. If the previous Internet era is a pure online information era, then the Internet of things will bring a new network era of Online + offline combination. All things are interconnected, which will greatly change our proction and life, improve and improve proctivity
then, how can blockchain and Internet of things be combined? Maybe there are different application scenarios in different instries. Recently, I saw a technology company called chaincmop chain computing, which has a smart farming management scheme that uses IOT equipment to monitor farm conditions + blockchain system in agricultural breeding, which is very enlightening. For example, in the future, you can use the Internet of things devices to detect the temperature, humidity and seed status of granary seeds in an all-round way, and these data can be synchronized and encrypted by using the distributed and encrypted features of the blockchain, so that the monitoring data can be more efficiently transmitted to each node, and the monitoring data can be well protected, To avoid tampering in the process of transmission.

5.

Because the blockchain technology is not mature at this stage, and the infrastructure is not perfect, many applications are limited, and the overall application is still in a very early stage

First of all, the main function of blockchain is to store information. Any information that needs to be saved can be written to or read from the blockchain, so it is a database. Secondly, anyone can set up a server and join the blockchain network to become a node. In the world of blockchain, there is no central node (decentralization). Every node is equal and keeps the whole database. You can write / read data to any node, because all nodes will be synchronized in the end to ensure the consistency of the blockchain

6. In recent years, more and more people travel abroad. A good credit card can add a lot to your journey. Everbright Bank is in love with the rhythm of tourism, and has launched a variety of tourism rights cards. Take this Everbright Caesar tourism platinum card as an example. There are many preferential rights and interests. The card and the first brush gift are very generous. Is it really that amazing? Follow Xiaobian to find out
Everbright Caesar travel white card gift
time: before June 30, 2018
Object: Everbright Caesar joint platinum MasterCard customers
ring the activity, customers who activate their credit cards and brush Everbright Caesar joint platinum MasterCard for the first time can enjoy 16 days of free overseas WiFi rights
you need to send self recording videos overseas, so you don't have to worry about non flow money anymore! It should be noted that each customer can only enjoy the right once a month, and only the top 300 customers can enjoy the right once a month
Everbright Caesar travel white card gift
event time: before June 30, 2018
event object: Everbright Caesar joint platinum card MasterCard customer
as long as Everbright Caesar joint platinum card MasterCard customer, ring the event period, the first brush and single currency transaction over $500 or more, you can get the value of 500 yuan of Jingdong e card rights
at the end of the next month after card consumption, the equity password of JD e card will be sent to your mobile phone in the form of SMS, regardless of name, no loss reporting, no cash exchange, and need to be kept properly
here is an introction to the opening ceremony and the first brush ceremony of Everbright Kaiser travel white. Of course, there are a lot of exclusive activities and services, such as Jingdong Mall's card consumption of 300 minus 100, the one-way airport shuttle service of 2 times / year, etc
recently, China Everbright Bank and Caesar tourism released their first joint brand card "Everbright Bank Caesar tourism platinum joint brand credit card" in Beijing. It is reported that the card is the highest level tourism exclusive card launched by both sides and is expected to cover millions of middle-class people in China
the Everbright Bank Kaiser Travel Co branded card launched this time is a platinum grade credit card, which is divided into UnionPay card and MasterCard. The design elements are mainly Aurora, and the design concept comes from "the world shines for me" - boundless dream. As long as you dare to pursue and set out, the world will shine for you
in addition to the basic rights and interests of Everbright, UnionPay and MasterCard platinum cards, the co branded card can also enjoy more exclusive rights and interests. For example, if a new user activates free international WiFi for 16 days, he or she can get the first swipe gift (if he or she swipes the card for more than $500, he or she will get the benefit of Jingdong e-card of $500). He or she can also enjoy airport shuttle, airport VIP hall, air delay insurance, travel accident insurance, road rescue, etc
What's more attractive is that cardholders can enjoy 5 times of points by consuming the whole line of Caesar procts, and they can grab 300 yuan of Caesar travel limited exclusive travel voucher by 1 yuan; Designated overseas cooperative merchants can enjoy 88% discount for consumption by card and customized tourism procts; You can also enter the aurora card zone of Caesar's official website and app as a privilege to purchase the specified preferential routes covering 100 countries and regions around the world, and over 10000 kinds of wonderful tourism procts will be put into the aurora card zone
Liu Yuxiao, general manager of Credit Card Center of China Everbright Bank, said: "this cooperation has effectively integrated the high-quality resources of both sides, and will provide cardholders with better daily travel services and the most convenient payment experience. This is an important step taken by Everbright credit card and Kaiser tourism in improving the quality and efficiency of serving the real economy, supporting the development of Inclusive Finance, and boosting the expansion of domestic demand. ".

7. The solutions are as follows:
1. Regularly clean the st in the computer, turn off the computer, open the chassis, use a hair dryer and blow with cold air< At ordinary times, 360 guard, Jinshan guard and other tools should be used to clean up the system garbage and temporary files generated by the Internet, and check and kill malicious

Italian software
3. The computer configuration is poor, so try to set the virtual memory as large as possible, and install anti-virus software with less resources, such as NOD32, or only one

auxiliary anti-virus software
4. Try to set the IP to static IP, which can rece the startup time of the computer
5. Don't put too many files and icons on the computer desktop, which will slow down the reaction of the computer. Try not to install the software on disk C
6. Regularly defragment the disk. Open the drive of my computer to defragment - properties - tools

select the disk to be defragmented. Open the "disk defragmenter" window - Analysis - defragmentation - the system will start to defragment

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