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Subtensor

This repository contains Bittensor's substrate-chain. Subtensor contains the trusted logic which:

1. Runs Bittensor's consensus mechanism;
2. Advertises neuron information, IPs, etc., and
3. Facilitates value transfer via TAO.

System Requirements

• The binaries in ./bin/release are x86_64 binaries to be used with the Linux kernel.
• Subtensor needs ~286 MiB to run.
• Architectures other than x86_64 are currently not supported.
• OSs other than Linux and MacOS are currently not supported.

Architectures

Subtensor support the following architectures:

Linux x86_64

Requirements:

• Linux kernel 2.6.32+,
• glibc 2.11+ A fresh FRAME-based Substrate node, ready for hacking 🚀

MacOS x86_64

Requirements:

• MacOS 10.7+ (Lion+)

Network requirements

• Subtensor needs access to the public internet
• Subtensor runs on ipv4
• Subtensor listens on the following ports:
  1. 9944 - Websocket. This port is used by bittensor. It only accepts connections from localhost. Make sure this port is firewalled off from the public domain.
  2. 9933 - RPC. This port is opened, but not used.
  3. 30333 - p2p socket. This port accepts connections from other subtensor nodes. Make sure your firewall(s) allow incoming traffic to this port.
• It is assumed your default outgoing traffic policy is ACCEPT. If not, make sure outbound traffic to port 30333 is allowed.

---

For Subnet Development

If you are developing and testing subnet incentive mechanism, you will need to run a local subtensor node. Follow the detailed step-by-step instructions provided in the document Running subtensor locally to run either a lite node or an archive node. Also see the Subtensor Nodes section in Bittensor Developer Documentation.

Lite node vs Archive node

For an explanation of lite node, archive node and how you can run your local subtensor node in these modes, see Lite node vs archive node section on Bittensor Developer Docs.

---

For Subtensor Development

Installation

First, complete the basic Rust setup instructions.

Build and Run

Use Rust's native cargo command to build and launch the template node:

cargo run --release -- --dev

Build only

The above cargo run command will perform an initial build and launch the node. Use the following command to build the node without launching it:

cargo build --release

Other ways to launch the node

The above cargo run command will launch a temporary node and its state will be discarded after you terminate the process. After the project has been built, there are other ways to launch the node.

Single-Node Development Chain

This command will start the single-node development chain with non-persistent state:

./target/release/subtensor --dev

Purge the development chain's state:

./target/release/subtensor purge-chain --dev

Start the development chain with detailed logging:

RUST_BACKTRACE=1 ./target/release/subtensor-ldebug --dev

Running debug with logs.

SKIP_WASM_BUILD=1 RUST_LOG=runtime=debug -- --nocapture

Running individual tests

SKIP_WASM_BUILD=1 \
  RUST_LOG=runtime=debug \
  cargo test <your test name> \
  -- --nocapture --color always

testing `tests/` tips

<package-name> Available members are found within the project root ./cargo.toml file, each point to a sub-directory containing a cargo.toml file with a name defined. for example, node/cargo.toml has a name of node-subtensor

<test-name> Available tests are often found within either a tests/ sub-directory or within the relevant src/ file. for example ./node/tests/chain_spec.rs has a test named chain_spec

example All together we can run all tests in chain_spec file from node-subtensor project via

skip_wasm_build=1 \
  rust_log=runtime=debug \
  cargo test \
  --package node-subtensor \
  --test chain_spec \
  -- --color always --nocapture

Running code coverage

bash scripts/code-coverage.sh

Note: They above requires cargo-tarpaulin is installed to the host, eg. cargo install cargo-tarpaulin Development chain means that the state of our chain will be in a tmp folder while the nodes are running. Also, alice account will be authority and sudo account as declared in the genesis state. At the same time the following accounts will be pre-funded:

• Alice
• Bob
• Alice//stash
• Bob//stash

If we want to maintain the chain state between runs, a base path must be added so the db can be stored in the provided folder instead of a temporal one. We could use this folder to store different chain databases, as a different folder will be created per different chain that is ran. The following commands show how to use a newly created folder as our db base path:

# Create a folder to use as the db base path
mkdir my-chain-state

# Use of that folder to store the chain state
./target/release/node-template --dev --base-path ./my-chain-state/

# Check the folder structure created inside the base path after running the chain
ls ./my-chain-state
#> chains
ls ./my-chain-state/chains/
#> dev
ls ./my-chain-state/chains/dev
#> db keystore network

Connect with Polkadot-JS Apps Front-end

Once the node template is running locally, you can connect it with Polkadot-JS Apps front-end to interact with your chain. Click here connecting the Apps to your local node template.

Multi-Node Local Testnet

If you want to see the multi-node consensus algorithm in action, refer to our Simulate a network tutorial.

Template Structure

A Substrate project such as this consists of a number of components that are spread across a few directories.

Node Capabilities

A blockchain node is an application that allows users to participate in a blockchain network. Substrate-based blockchain nodes expose a number of capabilities:

• Networking: Substrate nodes use the libp2p networking stack to allow the nodes in the network to communicate with one another.
• Consensus: Blockchains must have a way to come to consensus on the state of the network. Substrate makes it possible to supply custom consensus engines and also ships with several consensus mechanisms that have been built on top of Web3 Foundation research.
• RPC Server: A remote procedure call (RPC) server is used to interact with Substrate nodes.

Directory structure

There are several files in the node directory. Make a note of the following important files:

• chain_spec.rs: A chain specification is a source code file that defines a Substrate chain's initial (genesis) state. Chain specifications are useful for development and testing, and critical when architecting the launch of a production chain. Take note of the development_config and testnet_genesis functions, which are used to define the genesis state for the local development chain configuration. These functions identify some well-known accounts and use them to configure the blockchain's initial state.
• service.rs: This file defines the node implementation. Take note of the libraries that this file imports and the names of the functions it invokes. In particular, there are references to consensus-related topics, such as the block finalization and forks and other consensus mechanisms such as Aura for block authoring and GRANDPA for finality.

CLI help

After the node has been built, refer to the embedded documentation to learn more about the capabilities and configuration parameters that it exposes:

./target/release/node-subtensor --help

Runtime

In Substrate, the terms "runtime" and "state transition function" are analogous - they refer to the core logic of the blockchain that is responsible for validating blocks and executing the state changes they define. The Substrate project in this repository uses FRAME to construct a blockchain runtime. FRAME allows runtime developers to declare domain-specific logic in modules called "pallets". At the heart of FRAME is a helpful macro language that makes it easy to create pallets and flexibly compose them to create blockchains that can address a variety of needs.

Review the FRAME runtime implementation included in this template and note the following:

• This file configures several pallets to include in the runtime. Each pallet configuration is defined by a code block that begins with impl $PALLET_NAME::Config for Runtime.
• The pallets are composed into a single runtime by way of the construct_runtime! macro, which is part of the core FRAME Support system library.

Pallets

The runtime in this project is constructed using many FRAME pallets that ship with the core Substrate repository and a template pallet that is defined in the pallets directory.

A FRAME pallet is compromised of a number of blockchain primitives:

• Storage: FRAME defines a rich set of powerful storage abstractions that makes it easy to use Substrate's efficient key-value database to manage the evolving state of a blockchain.
• Dispatchables: FRAME pallets define special types of functions that can be invoked (dispatched) from outside of the runtime in order to update its state.
• Events: Substrate uses events and errors to notify users of important changes in the runtime.
• Errors: When a dispatchable fails, it returns an error.
• Config: The Config configuration interface is used to define the types and parameters upon which a FRAME pallet depends.

License

The MIT License (MIT) Copyright © 2021 Yuma Rao

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Acknowledgments

parralax