The message handling in this reactor is all under control of the reactor
itself, and does not call out to callbacks or other externally-supplied code.
It doesn't need to check for panics.
- Remove an irrelevant channel ID check.
- Remove an unnecessary panic recovery wrapper.
The PEX reactor has a simple feedback control mechanism to decide how often to
poll peers for peer address updates. The idea is to poll more frequently when
knowledge of the network is less, and decrease frequency as knowledge grows.
This change solves two problems:
1. It is possible in some cases we may poll a peer "too often" and get dropped
by that peer for spamming.
2. The first successful peer update with any content resets the polling timer
to a very long time (10m), meaning if we are unlucky in getting an
incomplete reply while the network is small, we may not try again for a very
long time. This may contribute to difficulties bootstrapping sync.
The main change here is to only update the interval when new information is
added to the system, and not (as before) whenever a request is sent out to a
peer. The rate computation is essentially the same as before, although the code
has been a bit simplified, and I consolidated some of the error handling so
that we don't have to check in multiple places for the same conditions.
Related changes:
- Improve error diagnostics for too-soon and overflow conditions.
- Clean up state handling in the poll interval computation.
- Pin the minimum interval avert a chance of PEX spamming a peer.
* p2p: migrate to use new interface for channel errors
* Update internal/p2p/p2ptest/require.go
Co-authored-by: M. J. Fromberger <michael.j.fromberger@gmail.com>
* rename
* feedback
Co-authored-by: M. J. Fromberger <michael.j.fromberger@gmail.com>
This continues the push of plumbing contexts through tendermint. I
attempted to find all goroutines in the production code (non-test) and
made sure that these threads would exit when their contexts were
canceled, and I believe this PR does that.
A few notes:
- this is not all the deletion that we can do, but this is the most
"simple" case: it leaves in shims, and there's some trivial
additional cleanup to the transport that can happen but that
requires writing more code, and I wanted this to be easy to review
above all else.
- This should land *after* we cut the branch for 0.35, but I'm
anticipating that to happen soon, and I wanted to run this through
CI.
This cleans up the `Router` code and adds a bunch of tests. These sorts of systems are a real pain to test, since they have a bunch of asynchronous goroutines living their own lives, so the test coverage is decent but not fantastic. Luckily we've been able to move all of the complex peer management and transport logic outside of the router, as synchronous components that are much easier to test, so the core router logic is fairly small and simple.
This also provides some initial test tooling in `p2p/p2ptest` that automatically sets up in-memory networks and channels for use in integration tests. It also includes channel-oriented test asserters in `p2p/p2ptest/require.go`, but these have primarily been written for router testing and should probably be adapted or extended for reactor testing.
This renames `PeerAddress` to `NodeAddress`, moves it and `NodeID` into a separate file `address.go`, adds tests for them, and fixes a bunch of bugs and inconsistencies.
This revises the new P2P `Transport` interface and does some preliminary code cleanups and simplifications.
The major change here is to add `Connection.Handshake()` for performing node handshakes (once the stream transport API is implemented, this can be done entirely independent of the transport). This moves most of the handshaking logic into the `Router`, such as prevention of head-of-line blocking, validation of peer's `NodeInfo`, controlling timeouts, and so on. This significantly simplifies transports, completely removes the need for internal goroutines, and shares common logic across all transports. This also allows varying the handshake `NodeInfo` across peers, e.g. to vary `ListenAddr`. Similarly, connection filtering is also moved into the switch/router so that it can be shared between transports.
This changes the new prototype PEX reactor to resolve peer address URLs into IP/port PEX addresses itself. Branched off of #5974.
I've spent some time thinking about address handling in the P2P stack. We currently use `PeerAddress` URLs everywhere, except for two places: when dialing a peer, and when exchanging addresses via PEX. We had two options:
1. Resolve addresses to endpoints inside `PeerManager`. This would introduce a lot of added complexity: we would have to track connection statistics per endpoint, have goroutines that asynchronously resolve and refresh these endpoints, deal with resolve scheduling before dialing (which is trickier than it sounds since it involves multiple goroutines in the peer manager and router and messes with peer rating order), handle IP address visibility issues, and so on.
2. Resolve addresses to endpoints (IP/port) only where they're used: when dialing, and in PEX. Everywhere else we use URLs.
I went with 2, because this significantly simplifies the handling of hostname resolution, and because I really think the PEX reactor should migrate to exchanging URLs instead of IP/port numbers anyway -- this allows operators to use DNS names for validators (and can easily migrate them to new IPs and/or load balance requests), and also allows different protocols (e.g. QUIC and `MemoryTransport`). Happy to discuss this.
Fixes#5899 by renaming a bunch of P2P Protobuf entities (while maintaining wire compatibility):
* `Message` to `PexMessage` (as it's only used for PEX messages).
* `PexAddrs` to `PexResponse`.
* `PexResponse.Addrs` to `PexResponse.Addresses`.
* `NetAddress` to `PexAddress` (as it's only used by PEX).
M. J. Fromberger
Sam Kleinman
Callum Waters
Aleksandr Bezobchuk
Erik Grinaker