The policy update logic that resided part in the gossiper and
part in the rpc server is extracted into its own object.
This prepares for additional validation logic to be added for policy
updates that would otherwise make the gossiper heavier.
It is also a small first step towards separation of our own channel data
from the rest of the graph.
As a preparation for making the gossiper less responsible for validating
and supplementing local channel policy updates, this commits moves the
on-the-fly max htlc migration up the call tree. The plan for a follow up
commit is to move it out of the gossiper completely for local channel
updates, so that we don't need to return a list of final applied policies
anymore.
In this commit, we fix a bug where if a user updates a forwarding policy to be
zero, the update will be applied to the policy correctly on-disk, but not
in-memory.
We solve this issue by having the gossiper return the list of on-disk updated
policies and passing these policies to the switch, so the switch can assume
that zero-valued fields are intentional and not just uninitialized.
There's no need to broadcast these as we assume that online nodes have
already received them. For nodes that were offline, they should receive
them as part of their initial graph sync.
This ensures that the graph synced status is marked true at some point
once a historical sync has completed. Before this commit, a stalled
historical sync could cause us to never mark the graph as synced.
In this commit, we modify the `SampleNodeAddrs` method to no longer
retry itself. Instead, we'll now leave this task to the caller of the
this method. Additionally, we'll no longer return with an error if we
can't hit a particular seed. Instead, we'll log the error and move onto
the next seed. Finally, we'll also no longer require that the DNS seed
has a secondary seed in order to support a wider array of DNS seeds.
We do this to ensure the node announcement propagates to our channel
counterparty. At times, the node announcement does not propagate to them
when opening our first channel due to a race condition between
IsPublicNode and processing announcement signatures. This isn't
necessary for channel updates and announcement signatures as we send
those to our channel counterparty directly through the reliable sender.
TestSyncManagerHistoricalSyncOnReconnect tests that the sync manager will
re-trigger a historical sync when a new peer connects after a historical
sync has completed, but we have lost all peers.
To handle the case where we have been without peers, and get a new
connection, we reset the historical scan booleans when the first active
syncer is connected to trigger another historical sync.
Prior to this change, the numQueryResponses that we calculated would be
one more than what we actually wanted since it didn't account for the
initial QueryChannelRange msg. This resulted in the test sending one
extra delayed query than was configured. This doesn't fundamentally
impact the test, but does make what happens in the test more reflective
of the configuration.
This commit makes all replies in the gossip syncer synchronous, meaning
that they will wait for each message to be successfully written to the
remote peer before attempting to send the next. This helps throttle
messages the remote peer has requested, preventing unintended
disconnects when the remote peer is slow to process messages. This
changes also helps out congestion in the peer by forcing the syncer to
buffer the messages instead of dumping them into the peer's queue.
This commit creates a distinct replyHandler, completely isolating the
requesting state machine from the processing of queries from the remote
peer. Before the two were interlaced, and the syncer could only reply to
messages in certain states. Now the two will be complete separated,
which is preliminary step to make the replies synchronous (as otherwise
we would be blocking our own requesting state machine).
With this changes, the channelGraphSyncer of each peer will drive the
replyHanlder of the other. The two can now operate independently, or
even spun up conditionally depending on advertised support for gossip
queries, as shown below:
A B
channelGraphSyncer ---control-msg--->
replyHandler
channelGraphSyncer <--control-msg----
gossiper <--gossip-msgs----
<--control-msg---- channelGraphSyncer
replyHandler
---control-msg---> channelGraphSyncer
---gossip-msgs---> gossiper
In this commit, we begin to queue any active syncers until the initial
historical sync has completed. We do this to ensure we can properly
handle any new channel updates at tip. This is required for fresh nodes
that are syncing the channel graph for the first time. If we begin
accepting updates at tip while the initial historical sync is still
ongoing, then we risk not processing certain updates since we've yet to
learn of the channels themselves.
In this commit, we add logic to handle a peer with whom we're performing
an initial historical sync disconnecting. This is required to ensure we
get as much of the graph as possible when starting a fresh node. It will
also serve useful to ensure we do not get stalled once we prevent active
GossipSyncers from starting until the initial historical sync has
completed.
Now that the roundRobinHandler is no longer present, this commit aims to
clean up and simplify some of the logic surrounding initializing/tearing
down new/stale GossipSyncers from the SyncManager. Along the way, we
also synchronize these calls with the syncerHandler, which will serve
useful in future work that allows us to recovery from initial historical
sync disconnections.
