consensus.md

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Consensus

Channel

Consensus has four separate channels. The channel identifiers are listed below.

Name	Number
StateChannel	32
DataChannel	33
VoteChannel	34
VoteSetBitsChannel	35

Message Types

Proposal

Proposal is sent when a new block is proposed. It is a suggestion of what the next block in the blockchain should be.

Name	Type	Description	Field Number
proposal	Proposal	Proposed Block to come to consensus on	1

Vote

Vote is sent to vote for some block (or to inform others that a process does not vote in the current round). Vote contains validator's information (validator address and index), height and round for which the vote is sent, vote type, blockID if process vote for some block (nil otherwise) and a timestamp when the vote is sent. The message is signed by the validator private key.

Name	Type	Description	Field Number
vote	Vote	Vote for a proposed Block	1

BlockPart

BlockPart is sent when gossiping a piece of the proposed block. It contains height, round and the block part.

Name	Type	Description	Field Number
height	int64	Height of corresponding block.	1
round	int32	Round of voting to finalize the block.	2
part	Part	A part of the block.	3

NewRoundStep

NewRoundStep is sent for every step transition during the core consensus algorithm execution. It is used in the gossip part of the CometBFT consensus protocol to inform peers about a current height/round/step a process is in.

Name	Type	Description	Field Number
height	int64	Height of corresponding block	1
round	int32	Round of voting to finalize the block.	2
step	uint32		3
seconds_since_start_time	int64		4
last_commit_round	int32		5

NewValidBlock

NewValidBlock is sent when a validator observes a valid block B in some round r, i.e., there is a Proposal for block B and 2/3+ prevotes for the block B in the round r. It contains height and round in which valid block is observed, block parts header that describes the valid block and is used to obtain all block parts, and a bit array of the block parts a process currently has, so its peers can know what parts it is missing so they can send them. In case the block is also committed, then IsCommit flag is set to true.

Name	Type	Description	Field Number
height	int64	Height of corresponding block	1
round	int32	Round of voting to finalize the block.	2
block_part_set_header	PartSetHeader		3
block_parts	int32		4
is_commit	bool		5

ProposalPOL

ProposalPOL is sent when a previous block is re-proposed. It is used to inform peers in what round the process learned for this block (ProposalPOLRound), and what prevotes for the re-proposed block the process has.

Name	Type	Description	Field Number
height	int64	Height of corresponding block	1
proposal_pol_round	int32		2
proposal_pol	bitarray		3

ReceivedVote

ReceivedVote is sent to indicate that a particular vote has been received. It contains height, round, vote type and the index of the validator that is the originator of the corresponding vote.

Name	Type	Description	Field Number
height	int64	Height of corresponding block	1
round	int32	Round of voting to finalize the block.	2
type	SignedMessageType		3
index	int32		4

VoteSetMaj23

VoteSetMaj23 is sent to indicate that a process has seen +2/3 votes for some BlockID. It contains height, round, vote type and the BlockID.

Name	Type	Description	Field Number
height	int64	Height of corresponding block	1
round	int32	Round of voting to finalize the block.	2
type	SignedMessageType		3

VoteSetBits

VoteSetBits is sent to communicate the bit-array of votes a process has seen for a given BlockID. It contains height, round, vote type, BlockID and a bit array of the votes a process has.

Name	Type	Description	Field Number
height	int64	Height of corresponding block	1
round	int32	Round of voting to finalize the block.	2
type	SignedMessageType		3
block_id	BlockID		4
votes	BitArray	Round of voting to finalize the block.	5

Message

Message is a oneof protobuf type.

Name	Type	Description	Field Number
new_round_step	NewRoundStep	Height of corresponding block	1
new_valid_block	NewValidBlock	Round of voting to finalize the block.	2
proposal	Proposal		3
proposal_pol	ProposalPOL		4
block_part	BlockPart		5
vote	Vote		6
received_vote	ReceivedVote		7
vote_set_maj23	VoteSetMaj23		8
vote_set_bits	VoteSetBits		9