[v1.4.1] Merge branch 'testing' into stable

Author: mratsim

CHANGELOG.md

@@ -1,3 +1,27 @@
+2021-07-10 v1.4.1
+=================
+
+Nimbus v1.4.1 - "Every attestation counts"
+
+This release is marked as `low-urgency`
+
+## Notable changes
+
+Nimbus `v1.4.0` users might have noticed that they are missing a small number of (seemingly random) attestations since the update. Our investigation into the matter has showed that, due to `v1.4.0`'s significant performance improvements, Nimbus validators occasionally send their first attestation for a new epoch before some peers are ready. These "slow" peers end up dropping early attestations because they're busy with the epoch transition.
+
+It's a rare occurrence, since it requires a validator to be scheduled to attest in the first slot of an epoch *and* for the beacon node to only be connected to "slow" peers for the respective libp2p topic. If both these conditions are true, a premature attestation may be lost in time, like tears in the rain.
+
+As a fix, we are using a larger send delay: [#2705](https://github.com/status-im/nimbus-eth2/pull/2705).
+
+Fo those Nimbus `v1.4.0` users who are concerned about reaching optimal attestation effectiveness, we encourage you to upgrade as soon as possible.
+
+Other changes include log flushing and metrics fixes.
+
+Full list:
+- increase attestation wait time ([#2705](https://github.com/status-im/nimbus-eth2/pull/2705))
+- ensure logs are printed without delays ([#2669](https://github.com/status-im/nimbus-eth2/pull/2669))
+- fix metrics on Windows ([#2707](https://github.com/status-im/nimbus-eth2/pull/2707))
+
 2021-06-21 v1.4.0
 =================
 

beacon_chain/nimbus_binary_common.nim

@@ -31,6 +31,7 @@ proc setupStdoutLogging*(logLevel: string) =
       proc (logLevel: LogLevel, msg: LogOutputStr) {.gcsafe, raises: [Defect].} =
         try:
           stdout.write(msg)
+          stdout.flushFile()
         except IOError as err:
           logLoggingFailure(cstring(msg), err)
 

beacon_chain/validators/validator_duties.nim

@@ -688,14 +688,18 @@ proc handleValidatorDuties*(node: BeaconNode, lastSlot, slot: Slot) {.async.} =
       # An opposite case is that we received (or produced) a block that has
       # not yet reached our neighbours. To protect against our attestations
       # being dropped (because the others have not yet seen the block), we'll
-      # impose a minimum delay of 250ms. The delay is enforced only when we're
+      # impose a minimum delay of 1000ms. The delay is enforced only when we're
       # not hitting the "normal" cutoff time for sending out attestations.
+      # An earlier delay of 250ms has proven to be not enough, increasing the
+      # risk of losing attestations.
+      # Regardless, because we "just" received the block, we'll impose the
+      # delay.
 
-      const afterBlockDelay = 250
+      const afterBlockDelay = 1000
       let
         afterBlockTime = node.beaconClock.now() + millis(afterBlockDelay)
         afterBlockCutoff = node.beaconClock.fromNow(
-          min(afterBlockTime, attestationCutoffTime))
+          min(afterBlockTime, attestationCutoffTime + millis(afterBlockDelay)))
 
       if afterBlockCutoff.inFuture:
         debug "Got block, waiting to send attestations",

beacon_chain/version.nim

@@ -16,7 +16,7 @@ when not defined(nimscript):
 const
   versionMajor* = 1
   versionMinor* = 4
-  versionBuild* = 0
+  versionBuild* = 1
 
   versionBlob* = "stateofus" # Single word - ends up in the default graffitti