52 lines
2.2 KiB
Markdown
52 lines
2.2 KiB
Markdown
<!--
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order: 2
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-->
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# State
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## Signing Info (Liveness)
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Every block includes a set of precommits by the validators for the previous block,
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known as the `LastCommitInfo` provided by Tendermint. A `LastCommitInfo` is valid so
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long as it contains precommits from +2/3 of total voting power.
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Proposers are incentivized to include precommits from all validators in the Tendermint `LastCommitInfo`
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by receiving additional fees proportional to the difference between the voting
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power included in the `LastCommitInfo` and +2/3 (see [fee distribution](x/distribution/spec/03_begin_block.md)).
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```
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type LastCommitInfo struct {
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Round int32
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Votes []VoteInfo
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}
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```
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Validators are penalized for failing to be included in the `LastCommitInfo` for some
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number of blocks by being automatically jailed, potentially slashed, and unbonded.
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Information about validator's liveness activity is tracked through `ValidatorSigningInfo`.
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It is indexed in the store as follows:
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- ValidatorSigningInfo: `0x01 | ConsAddrLen (1 byte) | ConsAddress -> ProtocolBuffer(ValSigningInfo)`
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- MissedBlocksBitArray: `0x02 | ConsAddrLen (1 byte) | ConsAddress | LittleEndianUint64(signArrayIndex) -> VarInt(didMiss)` (varint is a number encoding format)
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The first mapping allows us to easily lookup the recent signing info for a
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validator based on the validator's consensus address.
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The second mapping (`MissedBlocksBitArray`) acts
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as a bit-array of size `SignedBlocksWindow` that tells us if the validator missed
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the block for a given index in the bit-array. The index in the bit-array is given
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as little endian uint64.
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The result is a `varint` that takes on `0` or `1`, where `0` indicates the
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validator did not miss (did sign) the corresponding block, and `1` indicates
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they missed the block (did not sign).
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Note that the `MissedBlocksBitArray` is not explicitly initialized up-front. Keys
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are added as we progress through the first `SignedBlocksWindow` blocks for a newly
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bonded validator. The `SignedBlocksWindow` parameter defines the size
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(number of blocks) of the sliding window used to track validator liveness.
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The information stored for tracking validator liveness is as follows:
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+++ https://github.com/cosmos/cosmos-sdk/blob/v0.40.0/proto/cosmos/slashing/v1beta1/slashing.proto#L11-L33
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