[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>
* Happy New Year!
* Remove year entierly
Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>
* Remove years from copyright notice in the entire repo
---------
Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>
* remove v0 primitives from polkadot-primitives
* first pass: remove v0
* fix fallout in erasure-coding
* remove v1 primitives, consolidate to v2
* the great import update
* update runtime_api_impl_v1 to v2 as well
* guide: add `Version` request for runtime API
* add version query to runtime API
* reintroduce OldV1SessionInfo in a limited way
* Substrate companion: Authority discovery multiple peer ids
Authority discovery before had a fixed mapping from `PeerId` to
`AuthorityId`. This wasn't correct, as a `PeerId` can actually map to
multiple `AuthorityId`s. The linked Substrate pr fixes this.
https://github.com/paritytech/substrate/pull/10259
* Update node/network/availability-distribution/src/requester/mod.rs
* Update node/network/collator-protocol/src/validator_side/mod.rs
* Update node/network/statement-distribution/src/tests.rs
* Update guide
* Adapt to Substrate pr
* Update Substrate
Aaro Altonen