xpay: stop retrying a node that repeats unknown_next_peer - #9592
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vincenzopalazzo wants to merge 2 commits into
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vincenzopalazzo wants to merge 2 commits into
vincenzopalazzo wants to merge 2 commits into
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unknown_next_peer means the reporting node cannot forward, which is
what lnd returns when the next peer is offline. xpay only disables the
failed channel, so getroutes hands back every other channel through the
same node.
This test fails a hub with four exits using that code. On current xpay
it walks all four:
Failed after 4 attempts. We got a weird error (unknown_next_peer)
for 131x1x0/1 ... 124x1x0/1 ... 117x1x0/1 ... 110x2x0/0
assert 4 <= 2
Marked xfail until the next commit excludes the node after the repeat.
Changelog-None.
The previous commit fails because xpay disables only the channel. A
second unknown_next_peer from the same node now calls
askrene-disable-node on this payment's private layer, so getroutes
stops handing back the rest of its channels.
The first failure still only disables that channel. One stale scid
must not take a well-connected node out of every path.
temporary_channel_failure and fee or CLTV errors are unchanged.
Removes the xfail from test_xpay_unknown_next_peer_excludes_node.
With the fix that test stops after two attempts:
Repeated unknown_next_peer from <hub>: disabling node for this payment
Fixes ElementsProject#9590.
Changelog-Fixed: xpay no longer retries every channel through a node that keeps returning unknown_next_peer.
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Summary
xpaytreatedunknown_next_peeras a single-channel failure. That is the code lnd returns when the next peer is offline, so a well-connected node was retried on every other channel untilretry_forexpired. Fixes Bug:xpayfails because it keeps retrying paths over the same node #9590.unknown_next_peerfrom the same node callsaskrene-disable-nodeon the private payment layer, sogetroutesstops handing back the rest of its channels.Test plan
test_xpay_unknown_next_peer_excludes_nodefails on master: 4 attempts, oneunknown_next_peerper hub channel (assert 4 <= 2)Repeated unknown_next_peer from <hub>: disabling node for this payment