I noticed that run-route-infloop chose some worse-looking paths after
routing was fixed, eg the second node:
Before:
Destination node, success, probability, hops, fees, cltv, scid...
02b3aa1e4ed31be83cca4bd367b2c01e39502cb25e282a9b4520ad376a1ba0a01a,1,0.991856,2,1004,40,2572260x39x0/1,2131897x45x0/0
After:
Destination node, success, probability, hops, fees, cltv, scid...
02b3aa1e4ed31be83cca4bd367b2c01e39502cb25e282a9b4520ad376a1ba0a01a,1,0.954540,3,1046,46,2570715x21x0/1,2346882x26x14/1,2131897x45x0/0
This is because although the final costs don't reflect it, routing was taking
into account local channels, and 2572260x39x0/1 has a base fee of 2970.
There's an easy fix: when we the pay plugin creates localmods for our
gossip graph, add all local channels with delay and fees equal to 0.
We do the same thing in our unit test. This improves things across
the board:
Linear success probability (when found): min-max(mean +/- stddev)
Before: 0.487040-0.999543(0.952548+/-0.075)
After: 0.486985-0.999750(0.975978+/-0.053)
Hops:
Before: 1-5(2.98374+/-0.77)
After: 1-5(2.09593+/-0.63)
Fees:
Before: 0-50848(922.457+/-2.7e+03)
After: 0-50041(861.621+/-2.7e+03)
Delay (blocks):
Before: 0-196(65.8081+/-60)
After: 0-190(60.3285+/-60)
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Changelog-Changed: Plugins: `pay` route algorithm doesn't bias against our own "expensive" channels any more.
This is more thorough than the minimal one required for getroute(), including the feerates
and cltv deltas.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
