This commit adds an index bucket, disabledEdgePolicyBucket, for those
ChannelEdgePolicy with disabled bit on.
The main purpose is to be able to iterate over these fast when prune is
needed without the need for iterating the whole graph.
The entry points for accessing this index are:
1. When updating ChannelEdgePolicy - insert an entry.
2. When deleting ChannelEdge - delete the associated entries.
3. When querying for disabled channels - implemented DisabledChannelIDs
function
In this commit, we refactor DeleteChannelEdge to use ChannelIDs rather
than ChannelPoints. We do this as the only use of DeleteChannelEdge is
when we are pruning zombie channels from our graph. When running under a
light client, we are unable to obtain the ChannelPoint of each edge due
to the expensive operations required to do so. As a stop-gap, we'll
resort towards using an edge's ChannelID instead, which is already
gossiped between nodes.
This commit removes the MarkEdgeZombie method from channeldb. This
method is currently not used in any live code paths in production, and
is only used in unit tests. However, incorrect usage of this method
could result in an edge being present in both the zombie and channel
indexes, which deviates from any state we would expect to see in
production. Removing the method will help mitigate the potential for
writing incorrect unit tests in the future, by forcing zombie edges to
be created via the relevant, production APIs, e.g. DeleteChannelEdge.
The existing unit tests that use this method have been modified to use
the DeleteChannelEdge instead. No regressions were discovered in the
process.
This commit modifies FetchChanInfos to skip any channels that are not in
the graph at the time of the call. Currently the entire call will fail
if the edge is not found, which stalls a gossip sync in the following
scenario:
1. Remote peer queries for a channel range
2. We return the set of channel ids in that range
3. A channel from that set is removed from the graph, e.g. via close.
4. Remote peer queries for removed edge, causing the query to fail.
To remedy this, we will now skip any edges that are not known in the
database at the time of the query. This prevents the syncer state
machines from halting, which otherwise could only be resolved by
disconnecting and reconnecting.
This commit modifies FilterKnownChanIDs to skip edges that
we ourselves have deemed zombies. This prevents us from requesting
the updates from them, as this wastes bandwidth and cpu cycles.
In this commit, we extend the graph's FetchChannelEdgesByID and
HasChannelEdge methods to also check the zombie index whenever the edge
to be looked up doesn't exist within the edge index. We do this to
signal to callers that the edge is known, but only as a zombie, and the
only information that we have about the edge are the node public keys of
the two parties involved in the edge.
In the event that an edge does exist within the zombie index, we make
an additional check on edge policies to ensure they are not within the
router's pruning window, indicating that it is a fresh update.
We mark the edges as zombies when pruning them to ensure we don't
attempt to reprocess them later on. This also applies to channels that
have been removed from the graph due to being stale.
In this commit, we add a zombie edge index to the database. This allows
us to quickly determine across restarts whether we're attempting to
process an edge we've previously deemed as zombie.
In this commit:
* we partition lnwire.ChanUpdateFlag into two (ChanUpdateChanFlags and
ChanUpdateMsgFlags), from a uint16 to a pair of uint8's
* we rename the ChannelUpdate.Flags to ChannelFlags and add an
additional MessageFlags field, which will be used to indicate the
presence of the optional field HtlcMaximumMsat within the ChannelUpdate.
* we partition ChannelEdgePolicy.Flags into message and channel flags.
This change corresponds to the partitioning of the ChannelUpdate's Flags
field into MessageFlags and ChannelFlags.
Co-authored-by: Johan T. Halseth <johanth@gmail.com>
In this commit, we add a method to the ChannelGraph struct that
determines whether a node is seen as public based on graph's source
node's point of view.
timestamps
In this commit, we ensure policies for edges we create in
TestChanUpdatesInHorizon have different update timestamps. This ensures
that there are two entries per edge in the edge update index. Because of
this, the test will fail because ChanUpdatesInHorizon will return
duplicate channel edges due to looking at all the entries within the
edge update index. This will be addressed in a future commit to allow
the set of tests to pass once again.
In this commit, we extend TestChannelEdgePruningUpdateIndexDeletion test
to include one more update for each edge. By doing this, we can
correctly determine whether old entries were properly pruned from the
index once a new update has arrived.
Due to entries within the edge update index having a nil value, the
tests need to be modified to account for this. Previously, we'd assume
that if we were unable to retrieve a value for a certain key that the
entry was non-existent, which is why the improper pruning bug was not
caught. Instead, we'll assert the number of entries to be the expected
value and populate a lookup map to determine whether the correct entries
exist within it.
In this commit, we add a new test to expose a lurking bug within the
graph database code. As is, when we go to delete a node from the
database, we don't also remove the entries within the update index. As a
result, if a user attempted to call NodeUpdatesInHorizon (or typically
as part of the p2p handshake), we would error out, as we would try to
read a node that no longer existed in the graph, as it was pruned.
The commit ensures that for every channel, there will always
be two entries in the edges bucket. If the policy from one or
both ends of the channel is unknown, it is marked as such.
This allows efficient lookup of incoming edges. This is
required for backwards payment path finding.
In this commit, we update the ChannelView method to be compatible with
the new set of interfaces that require the script to be passed in in
addition to the outpoint. In order to do this, we introduce a new
EdgePoint struct which packages together a channel point along with the
funding pkScript. Along the way, we've copied over a utility method from
the lnwallet package to avoid having to deal with an import cycle.
In this commit, we extend the TestPruneGraphNodes test to also test the
case of when a node is involved in a channel, but only a single edge for
that channel has been advertised. In order to test this, we add an
additional node to the graph, and also a new channel. However, this
channel will only have a single edge advertised. As result, when we
prune the set of edges, the only node remaining should be the node that
didn't have any edges at all.
In this commit, we fix an existing bug in the new graph query sync
feature. Before this commit, when a block is pruned, we would never
actually delete the update index entries. This is due to the fact that
we would attempt to delete the entries from the update index _after_ we
had already removed the edges from the update index.
We fix this by simply swapping the order: first we delete from the
update index, then we delete the edges themselves. A test ensuring that
the entires are cleared (which failed before this commit), has been
added.
In this commit, we add a series of methods, and a new database index
that we'll use to implement the new discovery.ChannelGraphTimeSeries
interface interface. The primary change is that we now maintain two new
indexes tracking the last update time for each node, and the last update
time for each edge. These two indexes allow us to implement the
NodeUpdatesInHorizon and ChanUpdatesInHorizon methods. The remaining
methods added simply utilize the existing database indexes to allow us to
respond to any peer gossip range queries.
A set of new unit tests has been added to exercise the added logic.
In this commit, we make an API change that’s meant to reduce the amount
of garbage we generate when doing pathfinding or syncing nodes with our
latest graph state. Before this commit, we would always have to fully
decode the public key and signatures when reading a edge or vertex
struct. For the edges, we may need several EC operations to fully
decode all the pubkeys. This has been seen to generate a ton of
garbage, as well as slow down path finding a good bit.
To remedy this, we’ll now only ever read the *raw* bytes from disk. In
the event that we actually need to verify a signature (or w/e), only
*then* will we fully decode everything.
This commit adds the method DisconnectBlockAtHeight to the channel
graph database, making it possible to "rewind" the database in case
a block is disconnected from the main chain. To accomplish this,
a prune log is introduced, making it possible to keep track of the
point in time where the database was pruned. This is necessary for
the case where lnd might wake up on a stale branch, and must "walk
backwards" on this branch after it finds a common block fro the
graph database and the new main chain.
Adds a HaveNodeAnnouncement field to the LightningNode
struct, which is used to indicate if we have gotten
all the necessary information to fill the remaining
fields in the struct. If we haven't gotten a node
announcement for this specific node, then we only
know the pubkey, and can only fill that field in
the struct. Still, we should be able to add it to the
channel graph and use it for routes, as long as we
know about channels to this node.
This commit introduces a new method to the ChannelGraph struct:
ChannelView. This struct returns all the outpoints that represent the
set of active channels within the network. The set of items returned by
this new method will possibly shrink with each call to `PruneGraph`,
and possibly be expanded by each call to `AddChannelEdge`.
The graph pruning tests have been updated to ensure the description
above holds true.
This commit modifies the ForEachNode on the ChannelGraph and
ForEachChannel on the LightningNode struct to accept a database
transaction as its first argument. With this change, it’ll now be
possible to implement graph traversals that typically required a nested
loop with all the vertex loaded into memory using the callback API
instead:
c.ForEachNode(nil, func(tx, node) {
node.ForEachChannel(tx, func(…) {
})
})
