[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>
Runtime release 1.2 includes bumping of the ParachainHost APIs up to
v10, so let's move all the released APIs out of vstaging folder, this PR
does not include any logic changes only renaming of the modules and some
moving around.
Signed-off-by: Alexandru Gheorghe <alexandru.gheorghe@parity.io>
**Update:** Pushed additional changes based on the review comments.
**This pull request fixes various spelling mistakes in this
repository.**
Most of the changes are contained in the first **3** commits:
- `Fix spelling mistakes in comments and docs`
- `Fix spelling mistakes in test names`
- `Fix spelling mistakes in error messages, panic messages, logs and
tracing`
Other source code spelling mistakes are separated into individual
commits for easier reviewing:
- `Fix the spelling of 'authority'`
- `Fix the spelling of 'REASONABLE_HEADERS_IN_JUSTIFICATION_ANCESTRY'`
- `Fix the spelling of 'prev_enqueud_messages'`
- `Fix the spelling of 'endpoint'`
- `Fix the spelling of 'children'`
- `Fix the spelling of 'PenpalSiblingSovereignAccount'`
- `Fix the spelling of 'PenpalSudoAccount'`
- `Fix the spelling of 'insufficient'`
- `Fix the spelling of 'PalletXcmExtrinsicsBenchmark'`
- `Fix the spelling of 'subtracted'`
- `Fix the spelling of 'CandidatePendingAvailability'`
- `Fix the spelling of 'exclusive'`
- `Fix the spelling of 'until'`
- `Fix the spelling of 'discriminator'`
- `Fix the spelling of 'nonexistent'`
- `Fix the spelling of 'subsystem'`
- `Fix the spelling of 'indices'`
- `Fix the spelling of 'committed'`
- `Fix the spelling of 'topology'`
- `Fix the spelling of 'response'`
- `Fix the spelling of 'beneficiary'`
- `Fix the spelling of 'formatted'`
- `Fix the spelling of 'UNKNOWN_PROOF_REQUEST'`
- `Fix the spelling of 'succeeded'`
- `Fix the spelling of 'reopened'`
- `Fix the spelling of 'proposer'`
- `Fix the spelling of 'InstantiationNonce'`
- `Fix the spelling of 'depositor'`
- `Fix the spelling of 'expiration'`
- `Fix the spelling of 'phantom'`
- `Fix the spelling of 'AggregatedKeyValue'`
- `Fix the spelling of 'randomness'`
- `Fix the spelling of 'defendant'`
- `Fix the spelling of 'AquaticMammal'`
- `Fix the spelling of 'transactions'`
- `Fix the spelling of 'PassingTracingSubscriber'`
- `Fix the spelling of 'TxSignaturePayload'`
- `Fix the spelling of 'versioning'`
- `Fix the spelling of 'descendant'`
- `Fix the spelling of 'overridden'`
- `Fix the spelling of 'network'`
Let me know if this structure is adequate.
**Note:** The usage of the words `Merkle`, `Merkelize`, `Merklization`,
`Merkelization`, `Merkleization`, is somewhat inconsistent but I left it
as it is.
~~**Note:** In some places the term `Receival` is used to refer to
message reception, IMO `Reception` is the correct word here, but I left
it as it is.~~
~~**Note:** In some places the term `Overlayed` is used instead of the
more acceptable version `Overlaid` but I also left it as it is.~~
~~**Note:** In some places the term `Applyable` is used instead of the
correct version `Applicable` but I also left it as it is.~~
**Note:** Some usage of British vs American english e.g. `judgement` vs
`judgment`, `initialise` vs `initialize`, `optimise` vs `optimize` etc.
are both present in different places, but I suppose that's
understandable given the number of contributors.
~~**Note:** There is a spelling mistake in `.github/CODEOWNERS` but it
triggers errors in CI when I make changes to it, so I left it as it
is.~~
Adds availability-write regression tests.
The results for the `availability-distribution` subsystem are volatile,
so I had to reduce the precision of the test.
Fixes https://github.com/paritytech/polkadot-sdk/issues/3528
```rust
latency:
mean_latency_ms = 30 // common sense
std_dev = 2.0 // common sense
n_validators = 300 // max number of validators, from chain config
n_cores = 60 // 300/5
max_validators_per_core = 5 // default
min_pov_size = 5120 // max
max_pov_size = 5120 // max
peer_bandwidth = 44040192 // from the Parity's kusama validators
bandwidth = 44040192 // from the Parity's kusama validators
connectivity = 90 // we need to be connected to 90-95% of peers
```
### What's been done
- `subsystem-bench` has been split into two parts: a cli benchmark
runner and a library.
- The cli runner is quite simple. It just allows us to run `.yaml` based
test sequences. Now it should only be used to run benchmarks during
development.
- The library is used in the cli runner and in regression tests. Some
code is changed to make the library independent of the runner.
- Added first regression tests for availability read and write that
replicate existing test sequences.
### How we run regression tests
- Regression tests are simply rust integration tests without the
harnesses.
- They should only be compiled under the `subsystem-benchmarks` feature
to prevent them from running with other tests.
- This doesn't work when running tests with `nextest` in CI, so
additional filters have been added to the `nextest` runs.
- Each benchmark run takes a different time in the beginning, so we
"warm up" the tests until their CPU usage differs by only 1%.
- After the warm-up, we run the benchmarks a few more times and compare
the average with the exception using a precision.
### What is still wrong?
- I haven't managed to set up approval voting tests. The spread of their
results is too large and can't be narrowed down in a reasonable amount
of time in the warm-up phase.
- The tests start an unconfigurable prometheus endpoint inside, which
causes errors because they use the same 9999 port. I disable it with a
flag, but I think it's better to extract the endpoint launching outside
the test, as we already do with `valgrind` and `pyroscope`. But we still
use `prometheus` inside the tests.
### Future work
* https://github.com/paritytech/polkadot-sdk/issues/3528
* https://github.com/paritytech/polkadot-sdk/issues/3529
* https://github.com/paritytech/polkadot-sdk/issues/3530
* https://github.com/paritytech/polkadot-sdk/issues/3531
---------
Co-authored-by: Alexander Samusev <41779041+alvicsam@users.noreply.github.com>
Andrei Eres
