committer

b2-committer

Introduction

Details

https://github.com/b2network/b2-node/issues/93

Description

Step1：Rollup Aggregator invoke method verifyBatchesTrustedAggregator in PolygonZkEVM.sol
Step2: b2-committer listen for events (verifyBatchesTrustedAggregator) and store data in Mysql
Step3: b2-committer submit proposal to b2-node (send a transaction)

transaction {  
     "proposalId":  getLastProposalId() from b2-node api,
     "stateRoot": rootHash from a merkle tree which contains all the stateRoots of the batch, which are range of startBatchNum and endBatchNum,
     "rootHash" from a merkle tree which contains all the proofs of the batch, which are range of startBatchNum and endBatchNum,
     "startBatchNum": getFinalBatch() from b2-node rpc or rest interface,
     "endBatchNum": startBatchNum + 10 (defined a constant)

Generate a proposal in b2-node depends on this transaction.

proposal {  
    "transaction": transaction from above describe,
    "currentBlockNum": the current b2-node block number,
    "voteMax": how many b2-committer node need to vote,
    "txVoteNum": voteNums Step3,
    "resultVoteNum": voteNums Step8,
    "winAddress": which address has the entitlement to execute submitter to submit data(stateRoot and proof) to btc network
    "btcTxId": btc tx id which contains the stateRoot and proof  
    "voteAdressList": already vote address list,
    "state": (PENDING, SUCCESS, TIMEOUT),
}

simple algorithm about winAddressIndex

 winAddressIndex = tx_id% voteAdressList
 winAddress = voteAdressList[winAddressIndex]

you can get winAddress using api of b2-node.

after generated a proposal, put proposalId to channel[proposalId]

Step4: get proposalId from channel[proposalId]] and search proposal state from b2-node api. if state is PENDING, and check winAddress equal local b2-committer address, then execute submitter to submit data(stateRoot and proof) to btc network
Step5: get the btcTxId from Step4, and put it in channel[btcTxId], and then update finalBatchNum in b2-node
Step6: go service loop channel[btcTxId] and get the btcTxId, and query the blockNum of btc network by btcTxId. If blockNum is confirmed, then execute Step7.
Step7: the b2-committer which execute btc transaction and get the btcTxId update the proposal btcTxId.
Step8: every b2-committer node loop their channel[proposalId] to check btcTxId is null or not. If not, then check the btcTxId blockHeight and submit a transaction to b2-node to vote. resultVoteNum++. if resultVoteNum > 50%, then update state to SUCCESS.
Step9: loop check proposal by proposalId from channel[proposalId]. if the state of proposal is still PENDING and (currentBlockNum - proposal.currentBlockNum)> 10000, than update state to TIMEOUT and go to Step 3 again.

environment Variables

Run

go run main.go

base

main 09a262a7bb3d07500d3d6bbab6996ce6c4b31640