[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
* WIP: Get rid of request multiplexer.
* WIP
* Receiver for handling of incoming requests.
* Get rid of useless `Fault` abstraction.
The things the type system let us do are not worth getting abstracted in
its own type. Instead error handling is going to be merely a pattern.
* Make most things compile again.
* Port availability distribution away from request multiplexer.
* Formatting.
* Port dispute distribution over.
* Fixup statement distribution.
* Handle request directly in collator protocol.
+ Only allow fatal errors at top level.
* Use direct request channel for availability recovery.
* Finally get rid of request multiplexer
Fixes#2842 and paves the way for more back pressure possibilities.
* Fix overseer and statement distribution tests.
* Fix collator protocol and network bridge tests.
* Fix tests in availability recovery.
* Fix availability distribution tests.
* Fix dispute distribution tests.
* Add missing dependency
* Typos.
* Review remarks.
* More remarks.
* Simplify some Option / Result / ? operator patterns
When they identically match a combinator on those types.
Tool-aided by [comby-rust](https://github.com/huitseeker/comby-rust).
* adjust review comments
Co-authored-by: Shawn Tabrizi <shawntabrizi@gmail.com>
* tests/av-store: use future::join instead of future::select
* tests/backing: use future::join instead of future::select
* tests/provisioner: use future::join instead of future::select
* tests/av-dist: use future::join instead of future::select
* tests/av-recovery: use future::join instead of future::select
* tests/bridge: use future::join instead of future::select
* tests/collator-protocol: use future::join instead of future::select
* tests/stmt-dist: use future::join instead of future::select
* fix tests
* guide: declare one para as a collator
* add ParaId to Declare messages and clean up
* fix build
* fix the testerinos
* begin adding keystore to collator-protocol
* remove request_x_ctx
* add core_for_group
* add bump_rotation
* add some more helpers to subsystem-util
* change signing_key API to take ref
* determine current and next para assignments
* disconnect collators who are not on current or next para
* add collator peer count metric
* notes for later
* some fixes
* add data & keystore to test state
* add a test utility for answering runtime API requests
* fix existing collator tests
* add new tests
* remove sc_keystore
* update cargo lock
Co-authored-by: Andronik Ordian <write@reusable.software>
* availability-distribution: Retry on fail on next block.
Retry failed fetches on next block when still pending availability.
* Update node/network/availability-distribution/src/requester/fetch_task/mod.rs
Co-authored-by: Andronik Ordian <write@reusable.software>
* Fix existing tests.
* Add test for trying all validators.
* Add test for testing retries.
Co-authored-by: Andronik Ordian <write@reusable.software>
* WIP: Whole subsystem test.
* New tests compile.
* Avoid needless runtime queries for no validator nodes.
* Make tx and rx publicly accessible in virtual overseer.
This simplifies mocking in some cases, as tx can be cloned, but rx can
not.
* Whole subsystem test working.
* Update node/network/availability-distribution/src/session_cache.rs
Co-authored-by: Andronik Ordian <write@reusable.software>
* Update node/network/availability-distribution/src/session_cache.rs
Co-authored-by: Andronik Ordian <write@reusable.software>
* Document better what `None` return value means.
* Get rid of BitVec dependency.
* Update Cargo.lock
* Hopefully fixed implementers guide build.
Co-authored-by: Andronik Ordian <write@reusable.software>
Aaro Altonen