Files
pezkuwi-subxt/polkadot
Robert Klotzner ca6297c853 Reduce dispute coordinator load (#5785)
* Don't import backing statements directly

into the dispute coordinator. This also gets rid of a redundant
signature check. Both should have some impact on backing performance.
In general this PR should make us scale better in the number of parachains.

Reasoning (aka why this is fine):

For the signature check: As mentioned, it is a redundant check. The
signature has already been checked at this point. This is even made
obvious by the used types. The smart constructor is not perfect as
discussed [here](https://github.com/paritytech/polkadot/issues/3455),
but is still a reasonable security.

For not importing to the dispute-coordinator: This should be good as the
dispute coordinator does scrape backing votes from chain. This suffices
in practice as a super majority of validators must have seen a backing
fork in order for a candidate to get included and only included
candidates pose a threat to our system. The import from chain is
preferable over direct import of backing votes for two reasons:

1. The import is batched, greatly improving import performance. All
   backing votes for a candidate are imported with a single import.
   And indeed we were able to see in metrics that importing votes
   from chain is fast.
2. We do less work in general as not every candidate for which
   statements are gossiped might actually make it on a chain. The
   dispute coordinator as with the current implementation would still
   import and keep those votes around for six sessions.

While redundancy is good for reliability in the event of bugs, this also
comes at a non negligible cost. The dispute-coordinator right now is the
subsystem with the highest load, despite the fact that it should not be
doing much during mormal operation and it is only getting worse
with more parachains as the load is a direct function of the number of statements.

We'll see on Versi how much of a performance improvement this PR

* Get rid of dead code.

* Dont send approval vote

* Make it pass CI

* Bring back tests for fixing them later.

* Explicit signature check.

* Resurrect approval-voting tests (not fixed yet)

* Send out approval votes in dispute-distribution.

Use BTreeMap for ordered dispute votes.

* Bring back an important warning.

* Fix approval voting tests.

* Don't send out dispute message on import + test

+ Some cleanup.

* Guide changes.

Note that the introduced complexity is actually redundant.

* WIP: guide changes.

* Finish guide changes about dispute-coordinator

conceputally. Requires more proof read still.

Also removed obsolete implementation details, where the code is better
suited as the source of truth.

* Finish guide changes for now.

* Remove own approval vote import logic.

* Implement logic for retrieving approval-votes

into approval-voting and approval-distribution subsystems.

* Update roadmap/implementers-guide/src/node/disputes/dispute-coordinator.md

Co-authored-by: asynchronous rob <rphmeier@gmail.com>

* Review feedback.

In particular: Add note about disputes of non included candidates.

* Incorporate Review Remarks

* Get rid of superfluous space.

* Tidy up import logic a bit.

Logical vote import is now separated, making the code more readable and
maintainable.

Also: Accept import if there is at least one invalid signer that has not
exceeded its spam slots, instead of requiring all of them to not exceed
their limits. This is more correct and a preparation for vote batching.

* We don't need/have empty imports.

* Fix tests and bugs.

* Remove error prone redundancy.

* Import approval votes on dispute initiated/concluded.

* Add test for approval vote import.

* Make guide checker happy (hopefully)

* Another sanity check + better logs.

* Reasoning about boundedness.

* Use `CandidateIndex` as opposed to `CoreIndex`.

* Remove redundant import.

* Review remarks.

* Add metric for calls to request signatures

* More review remarks.

* Add metric on imported approval votes.

* Include candidate hash in logs.

* More trace log

* Break cycle.

* Add some tracing.

* Cleanup allowed messages.

* fmt

* Tracing + timeout for get inherent data.

* Better error.

* Break cycle in all places.

* Clarified comment some more.

* Typo.

* Break cycle approval-distribution - approval-voting.

Co-authored-by: asynchronous rob <rphmeier@gmail.com>
2022-08-16 08:16:30 +02:00
..
2022-07-28 11:04:20 +02:00
2022-07-06 06:54:38 +00:00
2022-08-04 13:24:34 +03:00
2022-07-26 14:37:02 +02:00
2022-07-20 18:32:02 +02:00
2022-08-01 10:55:51 +00:00

Polkadot

Implementation of a https://polkadot.network node in Rust based on the Substrate framework.

NOTE: In 2018, we split our implementation of "Polkadot" from its development framework "Substrate". See the Substrate repo for git history prior to 2018.

This repo contains runtimes for the Polkadot, Kusama, and Westend networks. The README provides information about installing the polkadot binary and developing on the codebase. For more specific guides, like how to be a validator, see the Polkadot Wiki.

Installation

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.

Installation from the Debian or rpm repositories 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.

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

RPM-based (Fedora, CentOS)

Currently supports Fedora 32 and CentOS 8, and derivatives.

# Install dnf-plugins-core (This might already be installed)
dnf install dnf-plugins-core
# Add the repository and enable it
dnf config-manager --add-repo https://releases.parity.io/rpm/polkadot.repo
dnf config-manager --set-enabled polkadot
# Install polkadot (You may have to confirm the import of the GPG key, which
# should have the following fingerprint: 9D4B2B6EB8F97156D19669A9FF0812D491B96798)
dnf install polkadot

Building

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 with:

cargo install --git https://github.com/paritytech/polkadot --tag <version> polkadot --locked

Build from Source

If you'd like to build from source, first install Rust. You may need to add Cargo's bin directory to your PATH environment variable. Restarting your computer will do this for you automatically.

curl https://sh.rustup.rs -sSf | sh

If you already have Rust installed, make sure you're using the latest version by running:

rustup update

Once done, finish installing the support software:

sudo apt install build-essential git clang libclang-dev pkg-config libssl-dev

Build the client by cloning this repository and running the following commands from the root directory of the repo:

git checkout <latest tagged release>
./scripts/init.sh
cargo build --release

Note that compilation is a memory intensive process. We recommend having 4 GiB of physical RAM or swap available (keep in mind that if a build hits swap it tends to be very slow).

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").

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").

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").

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. See the claims instructions for Polkadot if you have DOTs to claim. For Westend's WND tokens, see the faucet instructions on the Wiki.

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. This script will install or update Rust and install the required dependencies (this may take up to 30 minutes on Mac machines):

curl https://getsubstrate.io -sSf | bash -s -- --fast

Then, grab the Polkadot source code:

git clone https://github.com/paritytech/polkadot.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).

./scripts/init.sh   # Install WebAssembly. Update Rust
cargo build # Builds all native code

You can run the tests if you like:

cargo test --all --release

You can start a development chain with:

cargo run -- --dev

Detailed logs may be shown by running the node with the following environment variables set:

RUST_LOG=debug RUST_BACKTRACE=1 cargo run----dev

Development

You can run a simple single-node development "network" on your machine by running:

polkadot --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 --chain=polkadot-local --alice -d /tmp/alice

And in the other, run:

polkadot --chain=polkadot-local --bob -d /tmp/bob --port 30334 --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

Setup Prometheus and Grafana.

Once you set this up you can take a look at the Polkadot Grafana dashboards that we currently maintain.

Using Docker

Using Docker

Shell Completion

Shell Completion

Contributing

Contributing Guidelines

Contribution Guidelines

Contributor Code of Conduct

Code of Conduct

License

Polkadot is GPL 3.0 licensed.