Substrate Evaluation

Summary - Substrate is a chain layer which allows pluggable consensus, definition of storage through the seperation of “extrinsics” and abstracts the runtime design allowing for blockchain providers to decide which runtime best suits there application needs. It also has been built with light client protocol in mind with a number of storage and pruning options giving the ability to clearly seperated different actors requirements for infrastructure (e.g. participants can run a light client on a mobile device and validators can run full nodes with gauranteed performance and uptime). On top of this Polkadot sits as a relay chain (built on Substrate) which allows private chains to share infrastucture such as validators.

Reference Material

Blockchain Explorers

• polkadash.io
• polkascan.io
  • BBQ Birch - Testnet
• poc-2.plokadot.io
• Substrate Explorer
• Telemetry.polkadot.io

Relevant Documentation

• What is Substrate
  • Substrate Video - Slides
    • Potential Runtime Designs
  • Parity Substrate Wiki
• What is PolKadot
  • Polkadot Governance Video - Slides
  • Polkadot Whitepaper
  • Polkadot Video Slides
  • Substrate : A Rustic Vision of Polkadot by Gavin Wood Video - Slides
  • Gavin Wood Podcast on Polkadot, Sharding and Substrate
  • Polkadot runtime Environment : Alternative Implementation Grant - Github
• Token Economics - DOTS
• Secret Store shard key generation
• Parity Ethereum IPFS
• Cosmos vs Polkadot
• Polkadot POC Tutorials
• Polkadot on Reddit
• substrate.readme.io - Substrate Developers Hub
• Substrate Workshop - Video
• Substrate Web 3 Summit - Slides
• Building on Substrate
• Polkadot 2018 Recap

Relevant Code Links

Key Repositories

• ParityTech
  • Substrate
    • Generalize the Consensus Infrastructure
      • Pluggable Consensus Import Queue
  • Polkadot
  • WASMI
• Web Assembly (WASM)
  • GO - support for WASM
  • GO WAGON
  • GO Perlin
  • Rust Parity Tech WASMI

Functional Breakdown

Persistence

• Storage
  • RocksDB
  • DB Code
  • Data Overview - Light Client
    • Block Structure Slide 17 to 28
  • decl_storage - macro
  • Get and Set Storage
  • Light Client
    • DB Code
    • Light Client Code
    • Protocol Light Client Storage
  • Node
    • Client Code
  • Validator
  • Archive Node

Distribution

Discovery

Gossip

• libp2p
• Substrate Code - network libp2p
• Get and Set Storage
• Message Format
  • Substrate Primitives
  • Polkadot Parachain Primitives
  • Polkadot Collator - Logic

    Execution

• Runtime
• impl-stubs
• SRML
• SRML Node Template

Consensus

• Hybrid Consensus Slide
• Generalized Consensus Pull Request
• Consensus Code
• Rhododendron - Asynchronously safe BFT consensus, implementation in Rust
• Random Number Generation CSPRNG
  • Rust-Random
• Block Finality
  • GRANDPA (GHOST-based Recursive Ancestor Deriving Prefix Agreement)
    • Finality GANDPA Code
    • Substrate using GRANDPA
    • Full nodes should store a GRANDPA commit message
    • Dynamic Authority sets in GRANDPA

Polkadot - Relay Chain

• Whitepaper Overview - Participation in Polkadot - Page 4 gives an overview of the actors
• Collator
  • A collator node lives on a distinct parachain and submits a proposal fora state transition, along with a proof for its validity (what we might call a witness or block data).
• Pokadot Parachain - Defines primitive types for creating or validating a parachain.
• Statement Table - This stores messages other authorities issue about candidates.
• Network - Does the heavy lifting of routing the statements and gaining consensus across the relay chain (and associated parachains)
  • Consensus - The “consensus” networking code built on top of the base network service. This fulfills the polkadot_consensus::Network trait, providing a hook to be called each time consensus begins on a new chain head.
  • Consensus Pool - Bridge between the network and consensus service for getting collations to it.
  • Router - Statement routing and consensus table router implementation.
• Fisherman (Misbehaviour check) - Utility for substrate-based runtimes that want to check misbehavior reports.

Security

Signing

• ED25519

  Hashing

• Substrate Code - hashing.rs
• Blake2 use in substrate
• XXHASH use in substrate

  Privacy

Governance

Staking

Voting

Chaincode

• See WASM above
• Rust Parity Tech WASMI
• Use in Substrate Code

  Deployment

  Substrate

• Locally on Mac
• From Code Base

  Polkadot

Interledger

• Message Format
• Relay Chain
• Consensus Process

  Developer Tools

• API
  • Polkadot Javascript API
• RPC
  • Substrate Code
• CLI
  • CLI
• SDK

  Off Chain Orchestration

• Oracles
• Workflow

  Wallets

• Feather

  Chain Tools

• Governance
  • Democracy - Github
• Token Economics
• Token Standards

  Business Tools

• Analytics
• System Monitoring
• Deployment Tools

  Performance

Key Pull Requests or Features

Substrate Prototyping

• Background Material

Deploying a Substrate Chain

• Overview
• Locally
• From Code Base
• Current Issue with BBQ Birch - cause

Note by default chaindata is held in

Johns-MacBook-Pro-2:chains jincubator$ pwd
/Users/jincubator/Library/Application Support/Substrate/chains
Johns-MacBook-Pro-2:chains jincubator$ ll
total 0
drwxr-xr-x  5 jincubator  staff  160 Oct 22 21:31 bbq-birch
drwxr-xr-x  5 jincubator  staff  160 Oct 23 11:50 development
drwxr-xr-x  5 jincubator  staff  160 Oct 23 14:16 staging_testnet

and to purge a chain see

substrate purge-chain --help

Deploying Polkadot

• Overview

Deploying a simple contract

• Preparing to build on Polkadot
• Writing a WASM Contract

Running a Transaction

• Balance Transfer via API