2.2 KiB
State
Signing Info
Every block includes a set of precommits by the validators for the previous block, known as the LastCommit. A LastCommit is valid so long as it contains precommits from +2/3 of voting power.
Proposers are incentivized to include precommits from all validators in the LastCommit by receiving additional fees proportional to the difference between the voting power included in the LastCommit and +2/3 (see TODO).
Validators are penalized for failing to be included in the LastCommit for some number of blocks by being automatically unbonded.
Information about validator activity is tracked in a ValidatorSigningInfo.
It is indexed in the store as follows:
- SigningInfo:
0x01 | ValTendermintAddr -> amino(valSigningInfo) - SigningBitArray:
0x02 | ValTendermintAddr | LittleEndianUint64(signArrayIndex) -> VarInt(didSign)
The first map allows us to easily lookup the recent signing info for a
validator, according to the Tendermint validator address. The second map acts as
a bit-array of size SIGNED_BLOCKS_WINDOW that tells us if the validator signed for a given index in the bit-array.
The index in the bit-array is given as little endian uint64.
The result is a varint that takes on 0 or 1, where 0 indicates the
validator did not sign the corresponding block, and 1 indicates they did.
Note that the SigningBitArray is not explicitly initialized up-front. Keys are
added as we progress through the first SIGNED_BLOCKS_WINDOW blocks for a newly
bonded validator.
The information stored for tracking validator liveness is as follows:
type ValidatorSigningInfo struct {
StartHeight int64
IndexOffset int64
JailedUntil int64
SignedBlocksCounter int64
}
Where:
StartHeightis set to the height that the candidate became an active validator (with non-zero voting power).IndexOffsetis incremented each time the candidate was a bonded validator in a block (and may have signed a precommit or not).JailedUntilis set whenever the candidate is revoked due to downtimeSignedBlocksCounteris a counter kept to avoid unnecessary array reads.SignedBlocksBitArray.Sum() == SignedBlocksCounteralways.