We'll let the payment's lifecycle register each shard it's sending with
the ShardTracker, canceling failed shards. This will be the foundation
for correct AMP derivation for each shard we'll send.
We'll use this to keep track of the outstanding shards and which
preimages we are using for each. For now this is a simple map from
attempt ID to hash, but later we'll hide the AMP child derivation behind
this interface.
To distinguish the attempt's unique ID from the overall payment
identifier, we name it attemptID everywhere, and note that the
paymentHash argument won't be the actual payment hash for AMP payments.
If we have processed a terminal state while we're pathfinding
for another shard, the payment loop should not error out on
ErrPaymentTerminal. Instead, it would wait for our shards to
complete then cleanly exit.
Move our more generic terminal check forward so that we only
need to handle a single class of expected errors. This change
is mirrored in our mock, and our reproducing tests are updated
to assert that this move catches both classes of errors we get.
Add an additional stuck-payment case, where our payment gets
a terminal error while it has other htlcs in-flight, and a
shard fails with ErrTerminalPayment. This payment also falls in
our class of expected errors, but is not currently handled. The
mock is updated accordingly, using the same ordering as in our
real RegisterAttempt implementation.
This commit adds a test which demonstrates that payments can
get stuck if we receive a payment failure while we're pathfinding
for another shard, then try to dispatch a shard after we've
recorded a permanent failure. It also updates our mock to
only consider payments with no in-flight htlcs as in-flight,
to more closely represent our actual RegisterAttempt.
This commit adds a step to our payment lifecycle test to add
control over when we find a path for our payment, This is
required for testing race conditions around pathfinding
completing and payment failures being reported.
Update our single shard success case to use a route which
splits the payment amount in half. This change still tests
the case where reveal of the preimage counts as a success,
even if we don't have the full amount. This change is made
to cut down on potential races in this test case. While we
are waiting for collectResultAsync to report a success, the
payment lifecycle will continue trying to dispatch shards.
In the case where we send 1/4 of the payment amount, we
send 1 or 2 more shards, depending on how long collectAsync
takes. Reducing this test to send 1/2 of the payment amount
means that we will always only try one more shard before
waiting for our shard.
This commit updates our mock to more closely follow the behavior of the
switch for mocked calls to GetPaymentResult. As it stands, our tests
send a test-created error from the switch when we want to mock shutdown.
In reality, the switch will close its result channel, so we update this
test to follow that behavior. This matters for the commit that follows,
because we start checking the error our payments return. If we have an
error from the switch, our tests will fail with an error that we do
not encounter in practice.
In our payment lifecycle tests, we have two goroutines that
compete for the lock in our mock control tower: the resumePayment
loop which tries to call RegisterAttempt, and the collectResult
handler which is launched in a goroutine by collectResultAsync
and is responsible for various settle/fail calls.
The order that the lock is acquired by these goroutines is
arbitrary, and can lead to flakes in our tests if the step
that we do not intend to execute first gets the lock (eg,
we want to fail a payment in collectResult, but RegisterAttempt
gets there first). This commit moves contention for this lock
after our mock's various "state driving" channels, so that the
lock will be acquired in the order that the test intends it.
Now that we run each test individually, we don't need to buffer
our mock's channels anymore. This helps to tighten our test loop,
which currently can move on from a step before it's actually
been processed by the mock. This removal ensures that our payment
loop processes each of the test's steps before moving on to the
next once.
Update our payment lifecycle test to run each test case with
a fresh router. This prevents test cases from interacting with
each other. Names are also added for easy debugging.
As is, we don't check that our SendPayment call in
TestRouterPaymentStateMachine completes. This makes it easier
to create malformed tests that just run through steps but leave
the SendPayment call hanging. This commit adds a check that we
have completed our payment to help catch tests like this. We
also remove an unused quit channel.
In this commit, we add strict zombie pruning as a config level param.
This allow us to add the option for those that want a tighter graph, and
not change the default composition of the channel graph for most users
over night.
In addition, we expand the test case slightly by testing that the self
node won't be pruned, but also that if there's a node with only a single
known stale edge, then both variants will prune that edge.
Since zombie pruning can be very slow on some devices (e.g. mobile) it
would stall lnd startup. Since it is not essential for pruning to be
finished for lnd to be functional, we instead delay the initial prune by
30 seconds.
Note that we could also wait for the graphPruneInterval to tick, but
since this is by default 2 hours, it is unlikely that a mobile app will
ever be open that long.
Previously, we would always allow dependent jobs to be processed,
regardless of the result of its parent job's validation. This isn't
correct, as a parent job contains actions necessary to successfully
process a dependent job. A prime example of this can be found within the
AuthenticatedGossiper, where an incoming channel announcement and update
are both processed, but if the channel announcement job fails to
complete, then the gossiper is unable to properly validate the update.
This commit aims to address this by preventing the dependent jobs to
run.
This commit fixes the following potential deadlock situation:
* Pathfinding holds a database lock and tries to obtain a mission control lock
via GetProbability
* ReportPaymentSuccess/ReportPaymentFail holds a mission control lock
and tries to obtain a database lock to store the payment result.
This produces a race condition when reading AssumeChannelValid from a
different goroutine. Instead we isolate the test cases and initial
AssumeChannelValid properly.
This commit reduces the number of concurrent validation operations the
router will perform when fully validating the channel graph. Reports
from several users indicate that GetInfo would hang for several minutes,
which is believed to be caused by attempting to validate massive amounts
of channels in parallel. This commit returns the limit back to its
original state before adding the batched gossip improvements.
We keep the 1000 concurrent validation request limit for
AssumeChannelValid, since we don't fetch blocks in that case. This
allows us to still keep the performance benefits on mobile/low-resource
devices.
In this commit, we thread through the necessary state to allow users to
set a max shard amount. If this value is set, then this'll effectively
serve as a ceiling for all our split attempts. If we need to split,
we'll first try to use `paymentAmt/2`, if that's bigger than
`MaxShardAmt, then we'll use the latter instead.
Ideally in the future we have a dynamic way to automatically set both
the `MaxShardAmt` as well as `MaxParts` for users. Until then exposing
these two new fields will allow us to experiment with setting them
automatically using the RPC interface, and also give users a bit more
control over how we attempt to route payments, akin to coin control for
on-chain payments.
Fixes#4730
All of the other mission control exported functions acquire their locks
immediately, and do not lock in the subsequent unexported functions.
This commit moves the lock up for the report payment functions so that
mission control's config values are covered by this lock, in preparation
for allowing config to be updated at runtime. Moving this lock means
that we will hold the lock for the additional time it takes to store a
single result, AddResult, to the store.
We are going to use the config struct to allow getting and setting
of the mission control config in the commits that follow. Self node
is not something we want to change, so we move it out for better
separation.
