Initial implementation for the plan discussed here: https://github.com/paritytech/polkadot-sdk/issues/701 Built on top of https://github.com/paritytech/polkadot-sdk/pull/1178 v0: https://github.com/paritytech/polkadot/pull/7554, ## Overall idea When approval-voting checks a candidate and is ready to advertise the approval, defer it in a per-relay chain block until we either have MAX_APPROVAL_COALESCE_COUNT candidates to sign or a candidate has stayed MAX_APPROVALS_COALESCE_TICKS in the queue, in both cases we sign what candidates we have available. This should allow us to reduce the number of approvals messages we have to create/send/verify. The parameters are configurable, so we should find some values that balance: - Security of the network: Delaying broadcasting of an approval shouldn't but the finality at risk and to make sure that never happens we won't delay sending a vote if we are past 2/3 from the no-show time. - Scalability of the network: MAX_APPROVAL_COALESCE_COUNT = 1 & MAX_APPROVALS_COALESCE_TICKS =0, is what we have now and we know from the measurements we did on versi, it bottlenecks approval-distribution/approval-voting when increase significantly the number of validators and parachains - Block storage: In case of disputes we have to import this votes on chain and that increase the necessary storage with MAX_APPROVAL_COALESCE_COUNT * CandidateHash per vote. Given that disputes are not the normal way of the network functioning and we will limit MAX_APPROVAL_COALESCE_COUNT in the single digits numbers, this should be good enough. Alternatively, we could try to create a better way to store this on-chain through indirection, if that's needed. ## Other fixes: - Fixed the fact that we were sending random assignments to non-validators, that was wrong because those won't do anything with it and they won't gossip it either because they do not have a grid topology set, so we would waste the random assignments. - Added metrics to be able to debug potential no-shows and mis-processing of approvals/assignments. ## TODO: - [x] Get feedback, that this is moving in the right direction. @ordian @sandreim @eskimor @burdges, let me know what you think. - [x] More and more testing. - [x] Test in versi. - [x] Make MAX_APPROVAL_COALESCE_COUNT & MAX_APPROVAL_COALESCE_WAIT_MILLIS a parachain host configuration. - [x] Make sure the backwards compatibility works correctly - [x] Make sure this direction is compatible with other streams of work: https://github.com/paritytech/polkadot-sdk/issues/635 & https://github.com/paritytech/polkadot-sdk/issues/742 - [x] Final versi burn-in before merging --------- Signed-off-by: Alexandru Gheorghe <alexandru.gheorghe@parity.io>
Polkadot
Implementation of a https://polkadot.network node in Rust based on the Substrate framework.
The README provides information about installing the polkadot binary and developing on the codebase. For more specific
guides, like how to run a validator node, see the Polkadot Wiki.
Installation
Using a pre-compiled binary
If you just wish to run a Polkadot node without compiling it yourself, you may either run the latest binary from our releases page, or install Polkadot from one of our package repositories.
Debian-based (Debian, Ubuntu)
Currently supports Debian 10 (Buster) and Ubuntu 20.04 (Focal), and derivatives. Run the following
commands as the root user.
# Import the security@parity.io GPG key
gpg --recv-keys --keyserver hkps://keys.mailvelope.com 9D4B2B6EB8F97156D19669A9FF0812D491B96798
gpg --export 9D4B2B6EB8F97156D19669A9FF0812D491B96798 > /usr/share/keyrings/parity.gpg
# Add the Parity repository and update the package index
echo 'deb [signed-by=/usr/share/keyrings/parity.gpg] https://releases.parity.io/deb release main' > /etc/apt/sources.list.d/parity.list
apt update
# Install the `parity-keyring` package - This will ensure the GPG key
# used by APT remains up-to-date
apt install parity-keyring
# Install polkadot
apt install polkadot
Installation from the Debian repository will create a systemd service that can be used to run a
Polkadot node. This is disabled by default, and can be started by running systemctl start polkadot
on demand (use systemctl enable polkadot to make it auto-start after reboot). By default, it will
run as the polkadot user. Command-line flags passed to the binary can be customized by editing
/etc/default/polkadot. This file will not be overwritten on updating Polkadot. You may also just
run the node directly from the command-line.
Building
Since the Polkadot node is based on Substrate, first set up your build environment according to the Substrate installation instructions.
Install via Cargo
Make sure you have the support software installed from the Build from Source section below this section.
If you want to install Polkadot in your PATH, you can do so with:
cargo install --git https://github.com/paritytech/polkadot-sdk --tag <version> polkadot --locked
Build from Source
Build the client by cloning this repository and running the following commands from the root directory of the repo:
git checkout <latest tagged release>
cargo build --release
Note: if you want to move the built polkadot binary somewhere (e.g. into $PATH) you will also
need to move polkadot-execute-worker and polkadot-prepare-worker. You can let cargo do all this
for you by running:
cargo install --path . --locked
Build from Source with Docker
You can also build from source using Parity CI docker image:
git checkout <latest tagged release>
docker run --rm -it -w /shellhere/polkadot \
-v $(pwd):/shellhere/polkadot \
paritytech/ci-linux:production cargo build --release
sudo chown -R $(id -u):$(id -g) target/
If you want to reproduce other steps of CI process you can use the following guide.
Networks
This repo supports runtimes for Polkadot, Kusama, and Westend.
Connect to Polkadot Mainnet
Connect to the global Polkadot Mainnet network by running:
../target/release/polkadot --chain=polkadot
You can see your node on [telemetry] (set a custom name with --name "my custom name").
telemetry: https://telemetry.polkadot.io/#list/Polkadot
Connect to the "Kusama" Canary Network
Connect to the global Kusama canary network by running:
../target/release/polkadot --chain=kusama
You can see your node on [telemetry] (set a custom name with --name "my custom name").
telemetry: https://telemetry.polkadot.io/#list/Kusama
Connect to the Westend Testnet
Connect to the global Westend testnet by running:
../target/release/polkadot --chain=westend
You can see your node on [telemetry] (set a custom name with --name "my custom name").
telemetry: https://telemetry.polkadot.io/#list/Westend
Obtaining DOTs
If you want to do anything on Polkadot, Kusama, or Westend, then you'll need to get an account and some DOT, KSM, or WND tokens, respectively. Follow the instructions on the Wiki to obtain tokens for your testnet of choice.
Hacking on Polkadot
If you'd actually like to hack on Polkadot, you can grab the source code and build it. Ensure you have Rust and the support software installed.
Then, grab the Polkadot source code:
git clone https://github.com/paritytech/polkadot-sdk.git
cd polkadot
Then build the code. You will need to build in release mode (--release) to start a network. Only
use debug mode for development (faster compile times for development and testing).
cargo build
You can run the tests if you like:
cargo test --workspace --profile testnet
# Or run only the tests for specified crated
cargo test -p <crate-name> --profile testnet
You can start a development chain with:
cargo run --bin polkadot -- --dev
Detailed logs may be shown by running the node with the following environment variables set:
RUST_LOG=debug RUST_BACKTRACE=1 cargo run --bin polkadot -- --dev
Development
You can run a simple single-node development "network" on your machine by running:
cargo run --bin polkadot --release -- --dev
You can muck around by heading to https://polkadot.js.org/apps and choose "Local Node" from the Settings menu.
Local Two-node Testnet
If you want to see the multi-node consensus algorithm in action locally, then you can create a local testnet. You'll need two terminals open. In one, run:
polkadot --dev --alice -d /tmp/alice
And in the other, run:
polkadot --dev --bob -d /tmp/bob --bootnodes '/ip4/127.0.0.1/tcp/30333/p2p/ALICE_BOOTNODE_ID_HERE'
Ensure you replace ALICE_BOOTNODE_ID_HERE with the node ID from the output of the first terminal.
Monitoring
Once you set this up you can take a look at the Polkadot Grafana dashboards that we currently maintain.
Using Docker
Shell Completion
Contributing
Contributing Guidelines
Contributor Code of Conduct
License
Polkadot is GPL 3.0 licensed.