In this commit we introduce pruning of channel edges instead of channels.
Channel failures apply to a single direction and it is unnecessarily
restricting to prune both directions.
Hop maps were used in a test to verify the population of the hop map
itself and further only in a single function (getFailedChannelID).
Rewrote that function and removed the hop maps completely.
There is the general assumption that channel edge policy nodes are
ordered such that the node1 pubkey is smaller than the key of node 2. In
the test graph, this assumption didn't hold. This commit fixes the test
graph and also adds a check to prevent this from happening again.
This commit adds a new test that checks that the bandwidth hints are
considered correclty for local channels, and that disable flags are
ignored in this case.
To decouple our own path finding from the graph state, we don't consider
the disable bit when attempting to use local channels. Instead the
bandwidth hints will be zero for local inactive channels.
We alos modify the unit test to check that the disable flag is ignored
for local edges.
In this commit the dependency of unmarshallRoute on edge policies being
available is removed. Edge policies may be unknown and reported as nil.
SendToRoute does not need the policies, but it does need pubkeys of the
route hops. In this commit, unmarshallRoute is modified so that it
takes the pubkeys from edgeInfo instead of channelEdgePolicy.
In addition to this, the route structure is simplified. No more connection
to the database at that point. Fees are determined based on incoming and
outgoing amounts.
In this commit, a new weight function is introduced. This will create a
meaningful effect of time lock on route selection. Also, removes the
squaring of the fee term. This led to suboptimal routes.
Unit test added that covers the weight function and asserts that the
lowest fee route is indeed returned.
This comment extends the unit tests for NewRoute with checks
on the total time lock for a route as well as the expected time
lock values for every hop along the route.
This commit fixes the logic inside the newRoute function to
address the following problems:
- Fee calculation for a hop does not include the fee that needs
to be paid to the next hop.
- The incoming channel capacity "sanity" check does not include
the fee to be paid to the current hop.
- Extend SendRequest and QueryRoutesRequest protos
- newRoute function takes fee limit and cuts off routes that exceed it
- queryRoutes, payInvoice and sendPayment commands take the feeLimit inputs and pass them down to newRoute
- When no feeLimit is included, don't enforce any feeLimits at all (by setting feeLimit to maxValue)
In this commit, we introduce a new method to the channel router's config
struct: QueryBandwidth. This method allows the channel router to query
for the up-to-date available bandwidth of a particular link. In the case
that this link emanates from/to us, then we can query the switch to see
if the link is active (if not bandwidth is zero), and return the current
best estimate for the available bandwidth of the link. If the link,
isn't one of ours, then we can thread through the total maximal
capacity of the link.
In order to implement this, the missionControl struct will now query the
switch upon creation to obtain a fresh bandwidth snapshot. We take care
to do this in a distinct db transaction in order to now introduced a
circular waiting condition between the mutexes in bolt, and the channel
state machine.
The aim of this change is to reduce the number of unnecessary failures
during HTLC payment routing as we'll now skip any links that are
inactive, or just don't have enough bandwidth for the payment. Nodes
that have several hundred channels (all of which in various states of
activity and available bandwidth) should see a nice gain from this w.r.t
payment latency.
In this commit, we modify our path finding algorithm to take an
additional set of edges that are currently not known to us that are
used to temporarily extend our graph with during a payment session.
These edges should assist the sender of a payment in successfully
constructing a path to the destination.
These edges should usually represent private channels, as they are not
publicly advertised to the network for routing.
In this commit, we modify the edgeWeight function that’s used within
the findPath method to weight fees more heavily than the time lock
value at an edge. We do this in order to greedily prefer lower fees
during path finding. This is a simple stop gap in place of more complex
weighting parameters that will be investigated later.
We also modify the edge distance to use an int64 rather than a float.
Finally an additional test has been added in order to excessive this
new change. Before the commit, the test was failing as we preferred the
route with lower total time lock.
In this commit, we fix an existing bug that could cause lnd to crash if
we sent a payment, and the *destination* sent a temp channel failure
error message. When handling such a message, we’ll look in the nextHop
map to see which channel was *after* the node that sent the payment.
However, if the destination sends this error, then there’ll be no entry
in this map.
To address this case, we now add a prevHop map. If we attempt to lookup
a node in the nextHop map, and they don’t have an entry, then we’ll
consult the prevHop map.
We also update the set of tests to ensure that we’re properly setting
both the prevHop map and the nextHop map.
In this commit, we implement adherence of the disabled bit within a
ChannelUpdate during path finding. If a channel is marked as disabled,
then we won’t attempt to route through it. A test has been added to
exercise this new check.
Run go fmt so config file is formatted correctly. Also rename
newVertex to NewVertex in pathfind_test and notifications_test
as it is now exported from the routing package.
For Part 1 of Issue #275. Create isolated private struct in
networkHandler goroutine that will de-duplicate
announcements added to the batch. The struct contains maps
for each of channel announcements, channel updates, and
node announcements to keep track of unique announcements.
The struct has a Reset method to reset stored announcements, an
AddMsg(lnwire.Message) method to add a new message to the current
batch, and a Batch method to return the set of de-duplicated
announcements.
Also fix a few minor typos.
Before this commit, we would expect that structurally we don’t pay any
fee for the first hop, but do for the final hop. After the latest
commit, this is now flipped as when we say fee, we mean the fee that we
need to pay to transit a link. For the final hop, there’s no additional
distance to be traveled, so the fee is nothing.
In this commit we restore the in memory ChannelRouter as we’ll no
dynamically set the ChannelRouter’s pointer within he spec path finding
test example.
This commit modifies the path finding logic such that all path finding
is done inside a _single_ database transaction. With this change, we
ensure that we don’t end up possibly creating hundreds of database
transactions slowing down the path finding and payment sending process
all together.
In this commit we modify the newRoute function to also add the source
node to the nextHopMap index. With this addition the indexes will now
allow the router to react based on failures that occur during the
_first_ hop, meaning the channel directly attached to the source node.
This commit fixes an oversight in the path finding code when converting
a path into a route. Currently, for the last hop, we’d emplace the
expiry delta of the last hop within the per-hop payload. This was left
over from a prior version of the specification.
To fix this, we’ll now emplace the _absolute_ final HTLC expiry with
the payload, such that, the final hop that verify that the HTLC has not
been tampered with in flight.
