Keywords: block chain, distributed, Java, decentralized, structured network
1. Background
After the Java upgrade professional courses, the introduction of the knowledge chain block section, so use a few minutes for everyone to popularize the block chain "distributed shared books" block chain and a distributed network.
2. The story is introduced
There are a lot of spontaneous market traders, Joe Smith is selling vegetables, meat products selling John Doe, Wang Fifth selling aquatic products, inspectors do not come, there is no stall is at the center position, there is no one would stall there are other rights management to stall. They are all selling their own stuff, mutual non-interference.
One day the inspectors come, get rid of all the vendors, because the community built on this land markets require everyone in the sale of fixed area, and stalls for a fee.
3. Spontaneous market and distributed network?
Block chain "Distributed" means that it is a form of distributed network. You think, ah, trade between traditional Alipay, from user to user, there is always a middle Alipay card with a background in that. In the block chain network, there is no middleman between the user and the user, and everyone is equal, and free to trade.
Just as no spontaneous urban management market. As long as the inspectors do not come, it is not a single booth (user) is at the center position, there is no one stall (user) will have another booth (user) has permission management. Because everyone on an equal footing, so the distributed network, also known as distributed peer-to-peer network.
4. What is a distributed network features?
(1) ** decentralization. ** This above description has been clear enough.
(2) ** scalability. ** distributed network can be thought of as an infinite market, as long as people come to do business, you can find stalls. Therefore, at the beginning may be just a small part of doing business on the inside, then people will be more and more, this is scalability. In theory, users can join the distributed network is unlimited.
(3) ** robustness. ** distributed network because the user is decentralized, so some users have been little effect on the rest of the damage. For example, in a market sell bean curd was compromised, it does not affect the next General Assembly to sell beef business. When some user fails, the network can automatically adapt, it also allows users to freely join and leave, just like market stalls, you can choose not to stall and stall, if you do not swing, automatically there will be others to swing. So it is more robust.
(4) ** cost-effective. ** distributed network can have a good advantage. Because these users are in a state of distribution of computing tasks and data storage network that can be distributed to the user's computer. Full use of their computing and storage capacity idle, the performance also becomes better.
(5) ** privacy. ** In non-distributed network, to anonymous communication systems, we must rely on some intermediate server to perform. In a distributed network, all users of computers have become such a server, will greatly enhance the flexibility and reliability of anonymous communications, and therefore better able to achieve privacy protection.
5. Why distributed systems have unity?
A distributed network, in fact, is a unified whole composed of many users, is a system. For users, it is to do business in the same model. On the user's operating system, there is a middle software to implement this model.
Also to the market as an example. It showed the unity of these stalls transactions vary in different trading can be done, but the way the booth was the same. On top of all transactions, there is a fair way for everyone to build the same booth model.
World Wide Web is the way the World Wide Web everything looks like a document (web page) look.
6. What are the two distributed network architecture contains
Distributed network structure can generally be divided into two types: unstructured and structured network of networks.
Unstructured, the equivalent of a fair, just to give a piece of land, a piece of land children are free stall stall. In unstructured distributed network, each user node is connected to each other at random, so unstructured networks easier to build a distributed network, to become a piece of land. However, unstructured distributed network has a drawback, is that we are all looking to random children, a node wants to find what they want in here is too much trouble, it needs to send a request to many nodes until a suitable node reply. Just like in the marketplace, no partitions, you have to buy eggs, you have to walk everywhere or ask the person until you get a response, "I have eggs to sell this" so far.
Structured like a distributed network partition bazaar, vegetable area, fruits District, meat district, sub-sea areas is good, there is a structure. Therefore, the structure of the distributed network are linked through a specific network structure. It can solve the defect unstructured distributed network, as we go to market, to buy eggs went straight to the area, like eggs, a node can find a more efficient what they want.
