This commit adds a new interface `Cluster` to manage cluster-level
inputs grouping. This new interface replaces the `inputCluster` and will
be futher refactored so the sweeper can use a much smaller coin
selection lock.
This commit changes the source that drives the state changes in the
sweeper. Previously we used a ticker with default interval of 30s to
trigger sweepings periodically. The assumption is, within this 30s we'd
batch multiple inputs into one transaction to maximize profits. However,
the efficacy of this batch is questionable.
At a high level, we can put our inputs into two categories - one that's
forced, and one that's not. For forced inputs, we should sweep them
immediately as the force flag indicates they are very urgent, eg,
CPFPing the force closing tx. For non-forced inputs, such as anchors
or HTLCs with CLTV that's far away, we can wait to sweep them till a new
block comes in and triggers the sweeping process.
Eventually, all inputs will be deadline-aware, and the sweeper will
consult our fee bumper about the most economical fee rate to be used for
a given deadline. Since the deadlines here are blockstamp, it's also
easier to manage them if the sweeper is also using blockstamp instead of
timestamp.
sweeper
This commit implements a new method, `LookupInputMempoolSpend` to do
lookups in the mempool. This method is useful in the case when we only
want to know whether an input is already been spent in the mempool by
the time we call.
This commit removes the logic where we remove an input when it's been
published more than 10 times. This is needed as in our future fee
bumper, we might start with a low fee and rebroadcast the same input for
hundred of blocks.
This commit changes how a new input sweep request is handled - now we
will query the mempool and see if it's already been spent. If so, we'll
update its state as we may need to RBF this input.
This commit refactors the grouping logic into a new interface
`UtxoAggregator`, which makes it easier to write tests and opens
possibility for future customized clustering strategies.
The old clustering logic is kept as and moved into `SimpleAggregator`.
This commit adds a new interface `FeePreference` which makes it easier
to write unit tests and allows more customized implementation in
following commits.
This commit moves `DetermineFeePerKw` into the `Estimate` method on
`FeePreference`. A few callsites previously calling `DetermineFeePerKw`
without the max fee rate is now also temporarily fixed by forcing them
to use `Estimate` with the default sweeper max fee rate.
This commit refactors the sweeper so the method `feeRateForPreference`
is now moved to `FeePreference`, which makes our following refactor
easier to handle.
This commit modifies the sweeper store to save a `TxRecord` in db
instead of an empty byte slice. This record will later be used to bring
RBF-awareness to our sweeper.
For anchor channels and neutrino backends we need to make sure
that sweeps of the same exclusive group are removed when one of
them is confirmed. Otherwise for neutrino backends those sweep
transaction are always rebroadcasted and are blocking funds in
the worst case scenario.
This commit changes how we create the input sets which are used to
construct the sweeping transactions. Assume the sweeper has two inputs,
one is new and one is retried, we'd end up having two transactions,
- tx1: which spends both the new and old inputs.
- tx2: which spends the new inputs only.
When publishing these txes, depending on which one gets into the mempool
first, the other one will be viewed as an RBF for the first one since
they both spending the same input(the new input).
This is now fixed by only attempt to publish the second tx when there
isn't a first tx - when there is a tx1, it means the new inputs are
already used in this tx along with retried inputs, hence there's no need
to publish tx2 which spends the new inputs only.
This commit attempts to make the polling logic in sweeper more linear.
Previously, the sweep's timer is reset/restarted in multiple places,
such as when a new input comes in, or a new block comes in, or a
previous input being spent, making it difficult to follow. We now remove
the old timer and replaces it with a simple polling logic - we will
schedule sweeps every 5s(default), and if there's no input to be swept,
we'd skip, just like the previous `scheduleSweep` does.
It's also worthy noting that, although `scheduleSweep` triggers the
timer to tick, by the time we do the actual sweep in `sweepCluster`,
conditions may have changed. This is now also fixed because we only have
one place to create the clusters and sweeps.
This commit makes sure an input is only added to the cluster when it has
successfully estimated its fee rate. Previously, when an error is
returned from `feeRateForPreference`, we'd still add this input to the
cluster, resulting a **lower** fee rates being used because when
averaging the fee rates, we'd think this input has zero fee rate
specified.
An unit test is patched to make the method `clusterByLockTime` more
robust.
* sweep: use longer variable name for clarity in `addToState`
* sweeper: add more docs and debug logs
* sweep: prioritize smaller inputs when adding wallet UTXOs
This commit sorts wallet UTXOs by their values when using them for
sweeping inputs. This way we'd avoid locking large UTXOs when sweeping
inputs and also provide an opportunity to aggregate wallet UTXOs.
* contractcourt+itest: relax anchor sweeping for CPFP purpose
This commit changes from always sweeping anchor for a local force close
to only do so when there is an actual time pressure. After this change,
a forced anchor sweeping will only be attempted when the deadline is
less than 144 blocks.
* docs: update release notes
* itest: update test `testMultiHopHtlcLocalChainClaim` to skip CPFP
Since we now only perform CPFP when both the fee rate is higher and the
deadline is less than 144, we need to update the test to reflect that
Bob will not CPFP the force close tx for the channle Alice->Bob.
* itest: fix `testMultiHopRemoteForceCloseOnChainHtlcTimeout`
* itest: update related tests to reflect anchor sweeping
This commit updates all related tests to reflect the latest anchor
sweeping behavior. Previously, anchor sweeping is always attempted as
CPFP when a force close is broadcast, while now it only happens when the
deadline is less than 144. For non-CPFP purpose sweeping, it will happen
after one block is mined after the force close transaction is confirmed
as the anchor will be resent to the sweeper with a floor fee rate, hence
making it economical to sweep.
This commit updates the `fee()` method in `weightEstimator` to make sure
when doing CPFP we are not exceeding the max allowed fee rate. In order
to use the max fee rate, we need to modify several methods to pass the
configured value to the estimator.
