Files
pezkuwi-subxt/substrate/client/mixnet/src/protocol.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

74 lines
2.4 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/>.
use super::config::Config;
use mixnet::core::PACKET_SIZE;
use sc_network::{
config::{NonReservedPeerMode, SetConfig},
peer_store::PeerStoreProvider,
service::NotificationMetrics,
NetworkBackend, NotificationService, ProtocolName,
};
use sp_runtime::traits::Block as BlockT;
/// Returns the protocol name to use for the mixnet controlled by the given chain.
pub fn protocol_name(genesis_hash: &[u8], fork_id: Option<&str>) -> ProtocolName {
let name = if let Some(fork_id) = fork_id {
format!("/{}/{}/mixnet/1", array_bytes::bytes2hex("", genesis_hash), fork_id)
} else {
format!("/{}/mixnet/1", array_bytes::bytes2hex("", genesis_hash))
};
name.into()
}
/// Returns the peers set configuration for the mixnet protocol.
pub fn peers_set_config<Block: BlockT, Network: NetworkBackend<Block, <Block as BlockT>::Hash>>(
name: ProtocolName,
config: &Config,
metrics: NotificationMetrics,
peerstore_handle: std::sync::Arc<dyn PeerStoreProvider>,
) -> (Network::NotificationProtocolConfig, Box<dyn NotificationService>) {
let set_config = if config.substrate.num_gateway_slots != 0 {
// out_peers is always 0; we are only interested in connecting to mixnodes, which we do by
// setting them as reserved nodes
SetConfig {
in_peers: config.substrate.num_gateway_slots,
out_peers: 0,
reserved_nodes: Vec::new(),
non_reserved_mode: NonReservedPeerMode::Accept,
}
} else {
SetConfig {
in_peers: 0,
out_peers: 0,
reserved_nodes: Vec::new(),
non_reserved_mode: NonReservedPeerMode::Deny,
}
};
Network::notification_config(
name,
Vec::new(),
PACKET_SIZE as u64,
None,
set_config,
metrics,
peerstore_handle,
)
}