Editor's Note: This article comes fromZhikuang University (ID: gh_37c9e0eaf00a), reprinted by Odaily with authorization.
Editor's Note: This article comes from
, reprinted by Odaily with authorization.
What is Polkadot?
In the early morning of December 4th, Beijing time, at Polkadot’s official DeCoded conference, Parity core development engineer and Polkadot co-founder Robert Habermeier revealed that the current parachain development has entered the final stage and has the initial public testing conditions. It is expected that the parachain will be released in 2021. The parachain test network was released in January, and product-level delivery is expected to be achieved in February 2021.
The Kusama parachain slot auction is on the agenda, and it is time to have a comprehensive understanding of the Polkadot ecology. In this article, we introduce Polkadot from the aspects of token circulation, network roles, consensus mechanism, reward and punishment mechanism, parachain slot auction, etc., hoping to help you establish a basic understanding of Polkadot.
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What is Polkadot?
The core vision of Polkadot is cross-chain, which is a heterogeneous collection of multiple blockchains. Through the Polkadot network, communication and data transfer can be carried out between different blockchains. In order to realize this vision, the Polkadot network has designed the structure of relay chain, parachain and transfer bridge.
The relay chain is the core hub of the Polkadot network, ensuring the security of parachains and realizing communication between parachains, maintaining the security of the entire network.
The transfer bridge is responsible for connecting the Polkadot network and external blockchain networks, such as Bitcoin and Ethereum networks.
Theoretically, in the future, any two parallel chains can complete cross-chain interaction directly or through the relay chain.
Kusama is Polkadot's test network. New functions deployed on the Polkadot network must be tested on Kusama first, and then deployed to the Polkadot network after the test is successful. Of course, the value of Kusama is not only as a test network for Polkadot. Polkadot network applications are mainly positioned at the enterprise level, with a particularly high level of security and reliability; while Kusama is positioned to provide services for start-ups, with relatively low requirements for security and reliability.
The current total amount and circulation of Polkadot tokens
source:https://polkadot.subscan.io/
Polkadot’s token DOT had an initial total of 10 million before the split. It was split at 1:100 on August 22 this year. After the split, the initial total amount of DOT was 1 billion. As new blocks of the Polkadot network continue to be generated, DOT will also continue to inflate. The current annual inflation rate is about 10%.
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source:https://polkadot.js.org/apps/?rpc=wss%3A%2F%2Frpc.polkadot.io#/staking/targets
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source:https://polkadot.subscan.io/tools/charts?type=token
The Polkadot browser provides a way to view the number of DOTs released daily and the number of DOTs pledged daily.
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What roles are there in the Polkadot network?
Verifiers are the block producing nodes on the Polkadot network relay chain, and they maintain the security and stability of the Polkadot network online 24/7. Validators not only need to have the necessary skills, but also need to mortgage enough DOT. In the case that other skills and conditions are met, the number of pledged DOTs ranks in the validator node pool to become a validator. Currently, there are 254 Polkadot validators, and one is increasing every day. In the future, the Polkadot network will support more validators. Recently, the Web3 Foundation has created a thousand validator project for Polkadot, and will gradually increase the number of validators to about 1,000.
The nominator is the closest to the ordinary currency holder, and the nominator can pledge his DOT to a trusted validator to obtain income.
The collector is mainly responsible for collecting transaction information on the parachain and providing the collected information to the verifier. The work of the collector establishes the basis for the interaction between the parachain and the relay chain.
Phishers are similar to the police in the Polkadot network, responsible for monitoring and proving bad behavior of verifiers. The duties of collector and fisherman can be taken care of at the same time.
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Newly generated blocks must be valid on the latest finalized block. The BABE block production mechanism is similar to a game of throwing dice. The system gives a random number, and the points obtained by the verifier meet the system requirements, and the verifier is selected as the block verifier.
source:https://wiki.polkadot.network/docs/zh-CN/learn-consensus
In another case, in a certain Slot, none of the verifiers can find a random number that meets the system requirements. At this time, the system will run the second round of block generation rules, and the second round of block generation rules will produce secondary blocks (below 2) in the figure, the second round of block generation rules includes two types of block logic. The system first sorts all validators according to a specific algorithm, and the algorithm specifies a block validator, who will perform the second round of the dice throwing game , the block can be produced if the required points are obtained; however, the verifier may not get the required points in the second round of the dice throwing game. In order to avoid this situation, at the same time, the verifier also starts With aura's block generation logic, as long as the designated verifier is online, the block can be generated. If the designated validator is offline at this time, no block will be generated for this slot. Entering the next Slot, all validators start the next round of competition according to the above rules.
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As shown above, on the longest chain confirmed by GRANDPA, the chain with the most main blocks wins the competition and becomes the main chain.
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Incentive Mechanism of Polkadot Network
The verifier maintains the safe and stable operation of the Polkadot network, and the verifier can get the corresponding block reward. According to the ranking in the candidate node pool, the system updates the verifier every 24 hours (accurately one Era, that is, 14400 Slots), and the verifiers with bad behavior in the previous Era or the number of DOT pledges ranked candidates that did not enter the node pool Validators will be disqualified as validators.
Under different validator nodes, the number of pledged DOTs may be more or less, but all validator nodes have equal rights, and their probability of producing blocks is equal, which has nothing to do with the number of pledged DOTs.
After an Era is completely over, the rewards will be distributed according to the block production status of the validators within the Era cycle (although the probability of block production is equal, the actual number of blocks produced by each validator will vary). The validator's reward includes two parts: block reward and handling fee.
The handling fee part is relatively simple. The fee for each transfer transaction on the Polkadot chain is about 0.015dot, 20% of the handling fee belongs to the block verification node, and 80% belongs to the treasury.
But the distribution of block rewards is related to the pledge rate. If and only when the pledge rate (the total amount of pledged DOT/DOT) is 50%, 100% of the block rewards will be issued to validators. If the pledge rate deviates from 50%, part of the block rewards will flow to the treasury.
source:https://research.web3.foundation/en/latest/polkadot/Token%20Economics.html
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y-axis: (inflation rate and yield) percentage
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Blue line: Inflation rewards for staker participants
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If the pledge rate is 50%, then all system inflation will flow to the pledge participants. If it is higher or lower than this ratio, part of it will flow into the treasury. How much will flow to the treasury depends on the pledge rate. 10% minus the inflation reward difference of the pledge participants The value is the part that flows into the treasury.
This mechanism can better balance the pledge rate and liquidity of DOT. If the pledge rate is relatively low, the pledge is encouraged to increase the pledge income; as the pledge rate increases, the pledge yield gradually decreases to maintain DOT liquidity and parallel chain insertion. Slot auction demand.
What is the use of the DOT flowing into the treasury? The DOT in the treasury belongs to the Polkadot community. It is mainly used to reward the Polkadot community and support the Polkadot ecology. As small as the design of telegram emoticons, as large as the initial funds for Polkadot ecological project applications, they are all withdrawn from the treasury. The Polkadot treasury also has a destruction mechanism, and a part of it will be destroyed every month. Treasury destruction mechanism: Every 24 days, funds will be allocated to supported projects or activities, and 1% of the remaining funds will be directly destroyed after allocation.
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For the bad behavior of validators, the Polkadot network has Slash penalties. The amount of Slash is a fixed percentage, the more DOTs are pledged, the more DOTs will be Slashed. Since all validators in the node pool have the same probability of producing blocks, pledging more DOT by the same validator node will not only lower the pledge rate of return, but also increase the potential Slash loss. For users with a large number of coins, decentralized pledge can effectively reduce the risk of being slashed. All the confiscated DOTs will go to the treasury.
The greater the security threat of the verification node to the Polkadot network, the higher the proportion of being slashed, as follows:
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Source: Polkadot Research Institute
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Parachain Slot Auction Rules
The parachain slot auction is currently the most concerned thing on the Polkadot network. At Polkadot’s official DeCoded conference last week, Polkadot co-founder Robert Habermeier revealed that the development of the parachain has entered the final stage and has the initial public testing conditions. It is expected that the parachain will The parachain test network will be released in January 2021, and product-level delivery is expected to be achieved in February 2021.
The operation of the parallel chain needs to consume network computing resources, so the parallel chain slot has an upper limit and is a scarce resource. Gavin Wood said at the Polkadot China Tour event in July this year that the upper limit of the number of parachains will be around 100.
Matters related to Polkadot parachain slot auction:
1. The slot is only rented and not sold. The auction offers bids for four lease terms, each 6 months in length. Projects interested in participating in the auction may bid for a single or multiple adjacent lease periods.
2. The auction will only release one parachain slot each time, and the release of the next slot will have a certain time interval (the interval has not yet been determined, it may be a few weeks).
3. Reduce bidding raids through candle auctions. The slot auction will be divided into two phases - safety period and random period. DOT can be freely pledged in the two stages, and the auction will not end within the security period, but will drop the hammer at any time according to the random number on the chain after entering the second stage. In order to successfully win the slot, the projects participating in the auction need to pledge as many chips as possible before entering the second stage.
4. The slot auction has designed the "Initial Parachain Crowdfunding (IPO)" scheme, which allows projects to borrow from the outside, that is, through a series of incentives to attract others to lock more DOT to themselves. This also provides a wealth of investment options for DOT holders. They can choose to support projects in the auction module to lock their own DOT and earn income.
5. The slot auction will only lock DOT and will not sell it. After the lease period ends, all DOTs participating in the auction will be refunded. DOTs that have participated in the regular pledge cannot participate in the auction at the same time. The DOTs participating in the auction can no longer get regular pledge rewards, but instead get different rewards from various bidding projects.
Parachain slot auctions are a major benefit to the Polkadot ecosystem. Access to the parachain project party can hand over infrastructure-related work such as network security and cross-chain interaction to Polkadot, and focus on its own core business. Just like a certain brand opens its own specialty store in a highly commercialized business district, the specialty store can enjoy the basic supporting services such as passenger flow and real estate in the business district, so that it can focus on its core business.
If this model can be successful, the Polkadot ecology may also have a "flywheel effect". Joining the Polkadot ecological focus project can put more resources on the development of its own core business. These projects are relatively easier to succeed. These successful projects can attract more projects to join the Polkadot ecology, making the Polkadot ecology more abundant, Diverse, sound, and perfect, so that more projects can be attracted to the Polkadot ecosystem, and the "flywheel effect" will be formed.https://polkaproject.com/For the entire Polkadot ecosystem, the parachain slot auction model is like a horse racing mechanism. Only those projects with reasonable business logic, market recognition and sustainable development can stand out from many competitors, and projects with insufficient competitiveness will be gradually eliminated.
source:https://polkaproject.com/
The Polkadot ecology is currently very rich, and more than 300 projects have entered the Polkadot ecology. You can go to
