Polkadot WIKI
https://wiki.polkadot.network/en/latest/polkadot/build/build-with-polkadot/
parachain
An in-development extension to Substrate called Cumulus will allow any Substrate built chain to connect to Polkadot and become a parachain.
two ways for you to deploy your application:
as a smart contract on an existing parachain,
as your own parachain
Cumulus - a Polkadot-ready parachain
The goal of Cumulus is to be an extension of Substrate that will make any Substrate runtime compatible with Polkadot.
relay chain
relay chain itself will not support smart contracts
One project that has announced intent to become a Polkadot parachain with support for smart contracts is Edgeware.
https://edgewa.re/
- Rob's talk from EthCC introducing Cumulus
Relay chain
https://github.com/darwinia-network/darwinia
parachain
https://github.com/paritytech/cumulus
https://github.com/nczhu/parachain
https://github.com/alekspickle/basic_parachain
https://github.com/UltronAGI/substrate-ultron
test-parachains
git clone https://github.com/paritytech/polkadot.git
open source examples
Substrate Runtimes¶
Parity¶
- Shasper- Eth2.0 implemented as Substrate runtime.
- Substrate TCR- Token curated registry as a runtime module.
- Substrate ERC20 - ERC20 token standard implemented on Substrate.
Community¶
AdEx Payment Channels using Substrate. Video. Repo.
Robonomics modules for integrating with ROS. Repo
Plasma on Substrate implemented by Staked Technologies. Repo
Edgeware. Repo
Zerochain privacy-focused runtime module.
Zero-chain Repo
Bellman-substrate (zksnarks on substrate) Repo
Starlog, IPFS metadata on substrate. Repo
An example "Apple Store" to sell apples using Substrate. Repo
Darwinia, a cross-chain gaming platform. Repo
Joystream, a user governed video platform. Repo
IPFS browser. Repo
Substrate multisig. Repo
Merkle tree module. Repo
Parking spaces registry using Substrate. Repo
Substrate inherents sample. Repo
Collateralize non-fungible assets for cash. Repo
CidChain. Repo
Katal. Repo
Fixed-point arithmetic
Time in ISO8601 format
Permissioned Oracle
Ideas¶
- NFT
- Bonded Tokens
- New governance modules with different styles of voting & democracy
- Upgrade the TCR module
- IPFS integration
- Decentralized identity solutions
- Oracle module
- Implement Generalized State Channel/Plasma Chain
- Decentralized Exchange
- Tools for monitoring validator performance
- dApps across different parachains
A parachain has two major value adds that make it a desirable choice for a developer over creating a standalone chain:
- Shared security - removes the necessity of bootstrapping a chain's own validator set.
- Interchain communication - allows parachains to interoperate with each other through the ICMP protocol.
What is a PDK?¶
As mentioned, a PDK is a set of tools that allows developers to easily create a parachain. In practice this means that the PDK will consist of a couple key components:
- State transition function - a way for your application to move from one state to another state.
- Collator node - a type of peer-to-peer node in the Polkadot network with certain responsibilities in regard to parachains.
a collator node also acts as a light client for the Polkadot relay chain
https://wiki.polkadot.network/en/latest/polkadot/learn/parachains/
https://wiki.polkadot.network/en/latest/polkadot/learn/staking/
https://wiki.polkadot.network/en/latest/polkadot/learn/bridges/
Transaction on the relay-chain will likely be priced higher than they will be on parachains.
https://research.web3.foundation/en/latest/polkadot/GRANDPA/
Bridge¶
A node which acts as an intermediary between the Polkadot relay chain and an external chain, in such a way that it appears to the relay chain that the external chain is a parachain (i.e., meets the Polkadot Runtime Environment requirements). Bridges allow for interaction between other blockchains such as Ethereum and Bitcoin which are not natively compatible with Polkadot.
Collator¶
A node which maintains a parachain by collecting parachain transactions and producing state transition proofs for the validators.
Overview¶ICMP
- Interchain messages will not go on to the relay chain.
- Interchain messages will be constrained to a max size in bytes.
- Parachains are allowed to block messages from other parachains, in which case the dispatching parachain would be aware of this block.
- Collator nodes are responsible for routing messages between chains.
- Collators produce a list of "egress" messages and will receive the "ingress" messages from other parachains.
- On each block, parachains are expected to route messages from some subset of all other parachains.
- When a collator produces a new block to hand off to a validator, it will collect the latest ingress queue information and process it.
- Validators will check a proof that the new candidate for the next parachain block includes the processing of the expected ingress messages to that parachain.
为什么parachain和smart contract进行比较呢？
；；；有点水，还没看完，看完再做进一步整理；；；