Re-broadcast finalizations for past notarized blocks when finalizing later blocks #124
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
samliok
reviewed
Mar 17, 2025
epoch.go
Outdated
| // we receive a finalization certificate for a future round | ||
| e.Logger.Debug("Received a finalization certificate for a future sequence", zap.Uint64("seq", fCert.Finalization.Seq), zap.Uint64("nextSeqToCommit", nextSeqToCommit)) | ||
|
|
||
| if err := e.reBroadcastPastFinalizations(); err != nil { |
There was a problem hiding this comment.
nit but i think this should be rebroadcastPastFinalizations()
samliok
approved these changes
Mar 17, 2025
…ater blocks Currently, if a node misses a finalization message or a finalization certificate message for a round, it will not try to re-broadcast the finalization message for that round even if it finalizes a later round. In our implementation of Simplex, we can only commit a block if we have collected a finalization certificate for the block, even if a finalization certificate has been collected for a later block. Also, our implementation of Simplex commits blocks in-order. It follows from the above that a quorum of correct nodes cannot commit a block if a finalization certificate hasn't been collected for an ancestor block, because an ancestor block cannot be committed due to missing the finalization certificate. This commit makes the node re-broadcast finalizations for ancestor blocks of blocks for which a finalization certificate has been collected, but cannot be committed because it needs to collect finalization certificates for ancestor blocks. Signed-off-by: Yacov Manevich <yacov.manevich@avalabs.org>
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Currently, if a node misses a finalization message or a finalization certificate message for a round, it will not try to re-broadcast the finalization message for that round even if it finalizes a later round.
In our implementation of Simplex, we can only commit a block if we have collected a finalization certificate for the block, even if a finalization certificate has been collected for a later block.
Also, our implementation of Simplex commits blocks in-order.
It follows from the above that a quorum of correct nodes cannot commit a block if a finalization certificate hasn't been collected for an ancestor block, because an ancestor block cannot be committed due to missing the finalization certificate.
This commit makes the node re-broadcast finalizations for ancestor blocks of blocks for which a finalization certificate has been collected, but cannot be committed because it needs to collect finalization certificates for ancestor blocks.