Files
pezkuwi-subxt/substrate/client/authority-discovery/src/error.rs
T
Aaro Altonen 80616f6d03 Integrate litep2p into Polkadot SDK (#2944)
[litep2p](https://github.com/altonen/litep2p) is a libp2p-compatible P2P
networking library. It supports all of the features of `rust-libp2p`
that are currently being utilized by Polkadot SDK.

Compared to `rust-libp2p`, `litep2p` has a quite different architecture
which is why the new `litep2p` network backend is only able to use a
little of the existing code in `sc-network`. The design has been mainly
influenced by how we'd wish to structure our networking-related code in
Polkadot SDK: independent higher-levels protocols directly communicating
with the network over links that support bidirectional backpressure. A
good example would be `NotificationHandle`/`RequestResponseHandle`
abstractions which allow, e.g., `SyncingEngine` to directly communicate
with peers to announce/request blocks.

I've tried running `polkadot --network-backend litep2p` with a few
different peer configurations and there is a noticeable reduction in
networking CPU usage. For high load (`--out-peers 200`), networking CPU
usage goes down from ~110% to ~30% (80 pp) and for normal load
(`--out-peers 40`), the usage goes down from ~55% to ~18% (37 pp).

These should not be taken as final numbers because:

a) there are still some low-hanging optimization fruits, such as
enabling [receive window
auto-tuning](https://github.com/libp2p/rust-yamux/pull/176), integrating
`Peerset` more closely with `litep2p` or improving memory usage of the
WebSocket transport
b) fixing bugs/instabilities that incorrectly cause `litep2p` to do less
work will increase the networking CPU usage
c) verification in a more diverse set of tests/conditions is needed

Nevertheless, these numbers should give an early estimate for CPU usage
of the new networking backend.

This PR consists of three separate changes:
* introduce a generic `PeerId` (wrapper around `Multihash`) so that we
don't have use `NetworkService::PeerId` in every part of the code that
uses a `PeerId`
* introduce `NetworkBackend` trait, implement it for the libp2p network
stack and make Polkadot SDK generic over `NetworkBackend`
  * implement `NetworkBackend` for litep2p

The new library should be considered experimental which is why
`rust-libp2p` will remain as the default option for the time being. This
PR currently depends on the master branch of `litep2p` but I'll cut a
new release for the library once all review comments have been
addresses.

---------

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>
Co-authored-by: Dmitry Markin <dmitry@markin.tech>
Co-authored-by: Alexandru Vasile <60601340+lexnv@users.noreply.github.com>
Co-authored-by: Alexandru Vasile <alexandru.vasile@parity.io>
2024-04-08 16:44:13 +00:00

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2.8 KiB
Rust

// This file is part of Substrate.
// Copyright (C) Parity Technologies (UK) Ltd.
// SPDX-License-Identifier: GPL-3.0-or-later WITH Classpath-exception-2.0
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.
//! Authority discovery errors.
/// AuthorityDiscovery Result.
pub type Result<T> = std::result::Result<T, Error>;
/// Error type for the authority discovery module.
#[derive(Debug, thiserror::Error)]
#[allow(missing_docs)]
pub enum Error {
#[error("Received dht value found event with records with different keys.")]
ReceivingDhtValueFoundEventWithDifferentKeys,
#[error("Received dht value found event with no records.")]
ReceivingDhtValueFoundEventWithNoRecords,
#[error("Failed to verify a dht payload with the given signature.")]
VerifyingDhtPayload,
#[error("Failed to hash the authority id to be used as a dht key.")]
HashingAuthorityId(#[from] sc_network::multiaddr::multihash::Error),
#[error("Failed calling into the Substrate runtime: {0}")]
CallingRuntime(#[from] sp_blockchain::Error),
#[error("Received a dht record with a key that does not match any in-flight awaited keys.")]
ReceivingUnexpectedRecord,
#[error("Failed to encode a protobuf payload.")]
EncodingProto(#[from] prost::EncodeError),
#[error("Failed to decode a protobuf payload.")]
DecodingProto(#[from] prost::DecodeError),
#[error("Failed to encode or decode scale payload.")]
EncodingDecodingScale(#[from] codec::Error),
#[error("Failed to parse a libp2p multi address.")]
ParsingMultiaddress(#[from] sc_network::multiaddr::Error),
#[error("Failed to parse a libp2p key: {0}")]
ParsingLibp2pIdentity(String),
#[error("Failed to sign: {0}.")]
CannotSign(String),
#[error("Failed to register Prometheus metric.")]
Prometheus(#[from] prometheus_endpoint::PrometheusError),
#[error("Received authority record that contains addresses with multiple peer ids")]
ReceivingDhtValueFoundEventWithDifferentPeerIds,
#[error("Received authority record without any addresses having a peer id")]
ReceivingDhtValueFoundEventWithNoPeerIds,
#[error("Received authority record without a valid signature for the remote peer id.")]
MissingPeerIdSignature,
#[error("Unable to fetch best block.")]
BestBlockFetchingError,
}