* Restore `RequestResponse::throttled`.
In contrast to the existing "throttled" approach this PR adds back-
pressure to the protocol without requiring pre-existing knowledge
of all nodes about their limits. It adds small, CBOR-encoded headers
to the actual payload data. Extra credit messages communicate back
to the sender how many more requests it is allowed to send.
* Remove some noise.
* Resend credit grant after connection closed.
Should an error in some lower layer cause a connection to be closed,
our previously sent credit grant may not have reached the remote peer.
Therefore, pessimistically, a credit grant is resent whenever a
connection is closed. The remote ignores duplicate grants.
* Remove inbound/outbound tracking per peer.
* Send ACK as response to duplicate credit grants.
* Simplify.
* Fix grammar.
* Incorporate review feedback.
- Remove `ResponseSent` which was a leftover from previous attemps
and issue a credit grant immediately in `send_response`.
- Only resend credit grants after a connection is closed if we are
still connected to this peer.
* Move codec/header.rs to throttled/codec.rs.
* More review suggestions.
* Generalise `ProtocolWrapper` and use shorter prefix.
* Update protocols/request-response/src/lib.rs
Co-authored-by: Roman Borschel <romanb@users.noreply.github.com>
* Update protocols/request-response/src/throttled.rs
Co-authored-by: Roman Borschel <romanb@users.noreply.github.com>
* Update protocols/request-response/src/throttled.rs
Co-authored-by: Roman Borschel <romanb@users.noreply.github.com>
* Minor comment changes.
* Limit max. header size to 8KiB
* Always construct initial limit with 1.
Since honest senders always assume a send budget of 1 and wait for
credit afterwards, setting the default limit to a higher value
can only become effective after informing the peer about it which
means leaving `max_recv` at 1 and setting `next_max` to the desired
value.
* Use LRU cache to keep previous peer infos.
Peers may send all their requests, reconnect and send again all their
requests, starting from a fresh budget. The LRU cache keeps the peer
information around and reuses it when the peer reconnects, continuing
with the previous remaining limit.
Co-authored-by: Roman Borschel <romanb@users.noreply.github.com>
* Restore `RequestResponse::throttled`.
In contrast to the existing "throttled" approach this PR adds back-
pressure to the protocol without requiring pre-existing knowledge
of all nodes about their limits. It adds small, CBOR-encoded headers
to the actual payload data. Extra credit messages communicate back
to the sender how many more requests it is allowed to send.
* Remove some noise.
* Resend credit grant after connection closed.
Should an error in some lower layer cause a connection to be closed,
our previously sent credit grant may not have reached the remote peer.
Therefore, pessimistically, a credit grant is resent whenever a
connection is closed. The remote ignores duplicate grants.
* Remove inbound/outbound tracking per peer.
* Send ACK as response to duplicate credit grants.
* Simplify.
* Fix grammar.
* Incorporate review feedback.
- Remove `ResponseSent` which was a leftover from previous attemps
and issue a credit grant immediately in `send_response`.
- Only resend credit grants after a connection is closed if we are
still connected to this peer.
* Move codec/header.rs to throttled/codec.rs.
* More review suggestions.
* Generalise `ProtocolWrapper` and use shorter prefix.
* Update protocols/request-response/src/lib.rs
Co-authored-by: Roman Borschel <romanb@users.noreply.github.com>
* Update protocols/request-response/src/throttled.rs
Co-authored-by: Roman Borschel <romanb@users.noreply.github.com>
* Update protocols/request-response/src/throttled.rs
Co-authored-by: Roman Borschel <romanb@users.noreply.github.com>
* Minor comment changes.
* Limit max. header size to 8KiB
* Always construct initial limit with 1.
Since honest senders always assume a send budget of 1 and wait for
credit afterwards, setting the default limit to a higher value
can only become effective after informing the peer about it which
means leaving `max_recv` at 1 and setting `next_max` to the desired
value.
Co-authored-by: Roman Borschel <romanb@users.noreply.github.com>
* Use a single exchange instead of two one_shots.
* Add `Throttled` to libp2p-request-response.
Wraps the existing `RequestResponse` behaviour and applies strict limits
to the number of inbound and outbound requests per peer.
The wrapper is opt-in and if not used, the protocol behaviour of
`RequestResponse` does not change. This PR also does not introduce
an extra protocol, hence the limits applied need to be known a priori
for all nodes which is not always possible or desirable. As mentioned
in #1687 I think that we should eventually augment the protocol with
metadata which allows a more dynamic exchange of requests and responses.
This PR also replaces the two oneshot channels with a single one from the
scambio crate which saves one allocation per request/response. If not
desirable because the crate has seen less testing the first commit could
be reverted.
* Fix rustdoc error.
* Remove some leftovers from development.
* Add docs to `NetworBehaviourAction::{map_in,map_out}`.
* Apply suggestions from code review
Co-authored-by: Roman Borschel <romanb@users.noreply.github.com>
* Add `ping_protocol_throttled` test.
* Add another test.
* Revert "Use a single exchange instead of two one_shots."
This reverts commit e34e1297d411298f6c69e238aa6c96e0b795d989.
# Conflicts:
# protocols/request-response/Cargo.toml
# protocols/request-response/src/handler/protocol.rs
* Update CHANGELOG.
* Update CHANGELOG.
Co-authored-by: Roman Borschel <romanb@users.noreply.github.com>
