Per XLS-0095, we are taking steps to rename ripple(d) to xrpl(d).
This change specifically removes all copyright notices referencing Ripple, XRPLF, and certain affiliated contributors upon mutual agreement, so the notice in the LICENSE.md file applies throughout. Copyright notices referencing external contributions remain as-is. Duplicate verbiage is also removed.
Fix stalled consensus detection to prevent false positives in situations where there are no disputed transactions.
Stalled consensus detection was added to 2.5.0 in response to a network consensus halt that caused a round to run for over an hour. However, it has a flaw that makes it very easy to have false positives. Those false positives are usually mitigated by other checks that prevent them from having an effect, but there have been several instances of validators "running ahead" because there are circumstances where the other checks are "successful", allowing the stall state to be checked.
- Detects if the consensus process is "stalled". If it is, then we can declare a
consensus and end successfully even if we do not have 80% agreement on
our proposal.
- "Stalled" is defined as:
- We have a close time consensus
- Each disputed transaction is individually stalled:
- It has been in the final "stuck" 95% requirement for at least 2
(avMIN_ROUNDS) "inner rounds" of phaseEstablish,
- and either all of the other trusted proposers or this validator, if proposing,
have had the same vote(s) for at least 4 (avSTALLED_ROUNDS) "inner
rounds", and at least 80% of the validators (including this one, if
appropriate) agree about the vote (whether yes or no).
- If we have been in the establish phase for more than 10x the previous
consensus establish phase's time, then consensus is considered "expired",
and we will leave the round, which sends a partial validation (indicating
that the node is moving on without validating). Two restrictions avoid
prematurely exiting, or having an extended exit in extreme situations.
- The 10x time is clamped to be within a range of 15s
(ledgerMAX_CONSENSUS) to 120s (ledgerABANDON_CONSENSUS).
- If consensus has not had an opportunity to walk through all avalanche
states (defined as not going through 8 "inner rounds" of phaseEstablish),
then ConsensusState::Expired is treated as ConsensusState::No.
- When enough nodes leave the round, any remaining nodes will see they've
fallen behind, and move on, too, generally before hitting the timeout. Any
validations or partial validations sent during this time will help the
consensus process bring the nodes back together.
Combine multiple related debug log data points into a single
message. Allows quick correlation of events that
previously were either not logged or, if logged, strewn
across multiple lines, making correlation difficult.
The Heartbeat Timer and consensus ledger accept processing
each have this capability.
Also guarantees that log entries will be written if the
node is a validator, regardless of log severity level.
Otherwise, the level of these messages is at INFO severity.
