More metrics and test

eclair-core/src/main/scala/fr/acinq/eclair/payment/Monitoring.scala

@@ -20,6 +20,7 @@ import fr.acinq.bitcoin.scalacompat.Crypto.PublicKey
 import fr.acinq.eclair.MilliSatoshi
 import fr.acinq.eclair.channel.CMD_FAIL_HTLC
 import kamon.Kamon
+import kamon.metric.Histogram
 
 object Monitoring {
 
@@ -67,6 +68,10 @@ object Monitoring {
       PaymentNodeOutAmount.withoutTags().record(bucket, amount.truncateToSatoshi.toLong)
       PaymentNodeOut.withoutTags().record(bucket)
     }
+
+    private val RelayConfidence = Kamon.histogram("payment.relay.confidence", "Confidence (in percent) that the relayed HTLC will be fulfilled")
+    def relaySettleFulfill(confidence: Double) = RelayConfidence.withTag("status", "fulfill").record((confidence * 100).toLong)
+    def relaySettleFail(confidence: Double) = RelayConfidence.withTag("status", "fail").record((confidence * 100).toLong)
   }
 
   object Tags {

eclair-core/src/main/scala/fr/acinq/eclair/payment/relay/ChannelRelay.scala

@@ -163,20 +163,22 @@ class ChannelRelay private(nodeParams: NodeParams,
 
       case WrappedAddResponse(_: RES_SUCCESS[_]) =>
         context.log.debug("sent htlc to the downstream channel")
-        waitForAddSettled()
+        waitForAddSettled(confidence)
     }
 
-  def waitForAddSettled(): Behavior[Command] =
+  def waitForAddSettled(confidence: Double): Behavior[Command] =
     Behaviors.receiveMessagePartial {
       case WrappedAddResponse(RES_ADD_SETTLED(o: Origin.ChannelRelayedHot, htlc, fulfill: HtlcResult.Fulfill)) =>
         context.log.debug("relaying fulfill to upstream")
+        Metrics.relaySettleFulfill(confidence)
         val cmd = CMD_FULFILL_HTLC(o.originHtlcId, fulfill.paymentPreimage, commit = true)
         context.system.eventStream ! EventStream.Publish(ChannelPaymentRelayed(o.amountIn, o.amountOut, htlc.paymentHash, o.originChannelId, htlc.channelId, startedAt, TimestampMilli.now()))
         recordRelayDuration(isSuccess = true)
         safeSendAndStop(o.originChannelId, cmd)
 
       case WrappedAddResponse(RES_ADD_SETTLED(o: Origin.ChannelRelayedHot, _, fail: HtlcResult.Fail)) =>
         context.log.debug("relaying fail to upstream")
+        Metrics.relaySettleFail(confidence)
         Metrics.recordPaymentRelayFailed(Tags.FailureType.Remote, Tags.RelayType.Channel)
         val cmd = translateRelayFailure(o.originHtlcId, fail)
         recordRelayDuration(isSuccess = false)

eclair-core/src/test/scala/fr/acinq/eclair/reputation/ReputationSpec.scala

@@ -0,0 +1,67 @@
+/*
+ * Copyright 2023 ACINQ SAS
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package fr.acinq.eclair.reputation
+
+import fr.acinq.eclair.{MilliSatoshiLong, TimestampMilli}
+import fr.acinq.eclair.reputation.Reputation.ReputationConfig
+import org.scalatest.funsuite.AnyFunSuite
+import org.scalactic.Tolerance.convertNumericToPlusOrMinusWrapper
+
+import java.util.UUID
+import scala.concurrent.duration.DurationInt
+
+class ReputationSpec extends AnyFunSuite {
+  val (uuid1, uuid2, uuid3, uuid4, uuid5, uuid6, uuid7) = (UUID.randomUUID(), UUID.randomUUID(), UUID.randomUUID(), UUID.randomUUID(), UUID.randomUUID(), UUID.randomUUID(), UUID.randomUUID())
+
+  test("basic") {
+    var r = Reputation.init(ReputationConfig(1000000000 msat, 30 seconds))
+    r = r.attempt(uuid1, 10000 msat)
+    assert(r.confidence() == 0)
+    r = r.record(uuid1, isSuccess = true)
+    r = r.attempt(uuid2, 10000 msat)
+    assert(r.confidence() == 0.5)
+    r = r.attempt(uuid3, 10000 msat)
+    assert(r.confidence() === 0.333 +- 0.001)
+    r = r.record(uuid2, isSuccess = true)
+    r = r.record(uuid3, isSuccess = true)
+    r = r.attempt(uuid4, 1 msat)
+    assert(r.confidence() === 1.0 +- 0.001)
+    r = r.attempt(uuid5, 90000 msat)
+    assert(r.confidence() === 0.25 +- 0.001)
+    r = r.attempt(uuid6, 10000 msat)
+    assert(r.confidence() === (3.0 / 13) +- 0.001)
+    r = r.cancel(uuid5)
+    assert(r.confidence() === 0.75 +- 0.001)
+    r = r.record(uuid6, isSuccess = false)
+    assert(r.confidence() === 0.75 +- 0.001)
+    r = r.attempt(uuid7, 10000 msat)
+    assert(r.confidence() === 0.6 +- 0.001)
+  }
+
+  test("long HTLC") {
+    var r = Reputation.init(ReputationConfig(1000000000 msat, 1 second))
+    r = r.attempt(uuid1, 100000 msat)
+    assert(r.confidence() == 0)
+    r = r.record(uuid1, isSuccess = true)
+    assert(r.confidence() == 1)
+    r = r.attempt(uuid2, 1000 msat, TimestampMilli(0))
+    assert(r.confidence(TimestampMilli(0)) === 0.99 +- 0.001)
+    assert(r.confidence(TimestampMilli(0) + 100.seconds) == 0.5)
+    r = r.record(uuid2, isSuccess = false, now = TimestampMilli(0) + 100.seconds)
+    assert(r.confidence() == 0.5)
+  }
+}