Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Only disable channels ~10 min after disconnect, rather than one #2198

Merged
merged 2 commits into from
Apr 18, 2023

Conversation

TheBlueMatt
Copy link
Collaborator

We correctly send out a gossip channel disable update after one
full time tick being down (1-2 minutes). This is pretty nice in
that it avoids nodes trying to route through our nodes too often
if they're down. Other nodes have a much longer time window,
causing them to have much less aggressive channel disables. Sadly,
at one minute it's not super uncommon for tor nodes to get disabled
(once a day or so on two nodes I looked at), and this causes the
lightning terminal scorer to consider the LDK node unstable (even
though it's the one doing the disabling - so is online). This
causes user frustration and makes LDK look bad (even though it's
probably failing fewer payments).

Given this, and future switches to block-based channel_update
timestamp fields, it makes sense to go ahead and switch to delaying
channel disable announcements for 10 minutes. This puts us more in
line with other implementations and reduces gossip spam, at the
cost of less reliable payments.

Fixes #2175, at least the currently visible parts.

When generating a `channel_update` either in response to a fee
configuration change or an HTLC failure, we currently poll the
channel to check if the peer's connected when setting the disabled
bit in the `channel_update`. This could cause cases where we set
the disable bit even though the peer *just* disconnected, and don't
generate a followup broadcast `channel_update` with the disabled
bit unset.

While a node generally shouldn't rebroadcast a `channel_update` it
received in an onion, there's nothing inherently stopping them from
doing so. Obviously in the fee-update case we expect the message to
propagate.

Luckily, since we already "stage" disable-changed updates, we can
check the staged state and use that to set the disabled bit in all
`channel_update` cases.
We correctly send out a gossip channel disable update after one
full time tick being down (1-2 minutes). This is pretty nice in
that it avoids nodes trying to route through our nodes too often
if they're down. Other nodes have a much longer time window,
causing them to have much less aggressive channel disables. Sadly,
at one minute it's not super uncommon for tor nodes to get disabled
(once a day or so on two nodes I looked at), and this causes the
lightning terminal scorer to consider the LDK node unstable (even
though it's the one doing the disabling - so is online). This
causes user frustration and makes LDK look bad (even though it's
probably failing fewer payments).

Given this, and future switches to block-based `channel_update`
timestamp fields, it makes sense to go ahead and switch to delaying
channel disable announcements for 10 minutes. This puts us more in
line with other implementations and reduces gossip spam, at the
cost of less reliable payments.

Fixes lightningdevkit#2175, at least the currently visible parts.
@TheBlueMatt TheBlueMatt added this to the 0.0.115 milestone Apr 18, 2023
@codecov-commenter
Copy link

codecov-commenter commented Apr 18, 2023

Codecov Report

Patch coverage: 95.23% and project coverage change: -0.01 ⚠️

Comparison is base (2ebbe6f) 91.34% compared to head (89e063b) 91.34%.

📣 This organization is not using Codecov’s GitHub App Integration. We recommend you install it so Codecov can continue to function properly for your repositories. Learn more

Additional details and impacted files
@@            Coverage Diff             @@
##             main    #2198      +/-   ##
==========================================
- Coverage   91.34%   91.34%   -0.01%     
==========================================
  Files         102      102              
  Lines       50470    50492      +22     
  Branches    50470    50492      +22     
==========================================
+ Hits        46103    46121      +18     
- Misses       4367     4371       +4     
Impacted Files Coverage Δ
lightning/src/ln/functional_test_utils.rs 92.68% <ø> (ø)
lightning/src/ln/channel.rs 90.19% <50.00%> (+0.02%) ⬆️
lightning/src/ln/channelmanager.rs 89.18% <96.55%> (+0.01%) ⬆️
lightning/src/ln/functional_tests.rs 98.27% <100.00%> (+<0.01%) ⬆️
lightning/src/ln/onion_route_tests.rs 98.49% <100.00%> (+0.01%) ⬆️

... and 2 files with indirect coverage changes

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

☔ View full report in Codecov by Sentry.
📢 Do you have feedback about the report comment? Let us know in this issue.

// If the channel_update we're going to return is disabled (i.e. the
// peer has been disabled for some time), return `channel_disabled`,
// otherwise return `temporary_channel_failure`.
if chan_update_opt.as_ref().map(|u| u.contents.flags & 2 == 2).unwrap_or(false) {
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

The flag literals are never clear to me lol. But I know creating consts for all of them will be a bit noisy in the repo. I'd like to do it at some later stage though. Also with all the error codes.

Copy link
Collaborator Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Yea, we should, but doesn't have to happen now, its not much worse than it is upstream.

@TheBlueMatt TheBlueMatt merged commit a332bfc into lightningdevkit:main Apr 18, 2023
k0k0ne pushed a commit to bitlightlabs/rust-lightning that referenced this pull request Sep 30, 2024
0.0.115 - Apr 24, 2023 - "Rebroadcast the Bugfixes"

API Updates
===========

 * The MSRV of the main LDK crates has been increased to 1.48 (lightningdevkit#2107).
 * Attempting to claim an un-expired payment on a channel which has closed no
   longer fails. The expiry time of payments is exposed via
   `PaymentClaimable::claim_deadline` (lightningdevkit#2148).
 * `payment_metadata` is now supported in `Invoice` deserialization, sending,
   and receiving (via a new `RecipientOnionFields` struct) (lightningdevkit#2139, lightningdevkit#2127).
 * `Event::PaymentFailed` now exposes a failure reason (lightningdevkit#2142).
 * BOLT12 messages now support stateless generation and validation (lightningdevkit#1989).
 * The `NetworkGraph` is now pruned of stale data after RGS processing (lightningdevkit#2161).
 * Max inbound HTLCs in-flight can be changed in the handshake config (lightningdevkit#2138).
 * `lightning-transaction-sync` feature `esplora-async-https` was added (lightningdevkit#2085).
 * A `ChannelPending` event is now emitted after the initial handshake (lightningdevkit#2098).
 * `PaymentForwarded::outbound_amount_forwarded_msat` was added (lightningdevkit#2136).
 * `ChannelManager::list_channels_by_counterparty` was added (lightningdevkit#2079).
 * `ChannelDetails::feerate_sat_per_1000_weight` was added (lightningdevkit#2094).
 * `Invoice::fallback_addresses` was added to fetch `bitcoin` types (lightningdevkit#2023).
 * The offer/refund description is now exposed in `Invoice{,Request}` (lightningdevkit#2206).

Backwards Compatibility
=======================

 * Payments sent with the legacy `*_with_route` methods on LDK 0.0.115+ will no
   longer be retryable via the LDK 0.0.114- `retry_payment` method (lightningdevkit#2139).
 * `Event::PaymentPathFailed::retry` was removed and will always be `None` for
    payments initiated on 0.0.115 which fail on an earlier version (lightningdevkit#2063).
 * `Route`s and `PaymentParameters` with blinded path information will not be
   readable on prior versions of LDK. Such objects are not currently constructed
   by LDK, but may be when processing BOLT12 data in a coming release (lightningdevkit#2146).
 * Providing `ChannelMonitorUpdate`s generated by LDK 0.0.115 to a
   `ChannelMonitor` on 0.0.114 or before may panic (lightningdevkit#2059). Note that this is
   in general unsupported, and included here only for completeness.

Bug Fixes
=========

 * Fixed a case where `process_events_async` may `poll` a `Future` which has
   already completed (lightningdevkit#2081).
 * Fixed deserialization of `u16` arrays. This bug may have previously corrupted
   the historical buckets in a `ProbabilisticScorer`. Users relying on the
   historical buckets may wish to wipe their scorer on upgrade to remove corrupt
   data rather than waiting on it to decay (lightningdevkit#2191).
 * The `process_events_async` task is now `Send` and can thus be polled on a
   multi-threaded runtime (lightningdevkit#2199).
 * Fixed a missing macro export causing
   `impl_writeable_tlv_based_enum{,_upgradable}` calls to not compile (lightningdevkit#2091).
 * Fixed compilation of `lightning-invoice` with both `no-std` and serde (lightningdevkit#2187)
 * Fix an issue where the `background-processor` would not wake when a
   `ChannelMonitorUpdate` completed asynchronously, causing delays (lightningdevkit#2090).
 * Fix an issue where `process_events_async` would exit immediately (lightningdevkit#2145).
 * `Router` calls from the `ChannelManager` now call `find_route_with_id` rather
   than `find_route`, as was intended and described in the API (lightningdevkit#2092).
 * Ensure `process_events_async` always exits if any sleep future returns true,
   not just if all sleep futures repeatedly return true (lightningdevkit#2145).
 * `channel_update` messages no longer set the disable bit unless the peer has
   been disconnected for some time. This should resolve cases where channels are
   disabled for extended periods of time (lightningdevkit#2198).
 * We no longer remove CLN nodes from the network graph for violating the BOLT
   spec in some cases after failing to pay through them (lightningdevkit#2220).
 * Fixed a debug assertion which may panic under heavy load (lightningdevkit#2172).
 * `CounterpartyForceClosed::peer_msg` is now wrapped in UntrustedString (lightningdevkit#2114)
 * Fixed a potential deadlock in `funding_transaction_generated` (lightningdevkit#2158).

Security
========

 * Transaction re-broadcasting is now substantially more aggressive, including a
   new regular rebroadcast feature called on a timer from the
   `background-processor` or from `ChainMonitor::rebroadcast_pending_claims`.
   This should substantially increase transaction confirmation reliability
   without relying on downstream `TransactionBroadcaster` implementations for
   rebroadcasting (lightningdevkit#2203, lightningdevkit#2205, lightningdevkit#2208).
 * Implemented the changes from BOLT PRs lightningdevkit#1031, lightningdevkit#1032, and lightningdevkit#1040 which resolve a
   privacy vulnerability which allows an intermediate node on the path to
   discover the final destination for a payment (lightningdevkit#2062).

In total, this release features 110 files changed, 11928 insertions, 6368
deletions in 215 commits from 21 authors, in alphabetical order:
 * Advait
 * Alan Cohen
 * Alec Chen
 * Allan Douglas R. de Oliveira
 * Arik Sosman
 * Elias Rohrer
 * Evan Feenstra
 * Jeffrey Czyz
 * John Cantrell
 * Lucas Soriano del Pino
 * Marc Tyndel
 * Matt Corallo
 * Paul Miller
 * Steven
 * Steven Williamson
 * Steven Zhao
 * Tony Giorgio
 * Valentine Wallace
 * Wilmer Paulino
 * benthecarman
 * munjesi
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
None yet
Projects
None yet
Development

Successfully merging this pull request may close these issues.

Move to block-based channel disable updates
4 participants