How to build BTM pool

How to build BTM pool

config the node

• when testing, could try switching to the testnet or solonet
  • ./bytomd init --chain_id testnet
  • or ./bytomd init --chain_id solonet , with a lower difficulty, in order to mine with cpu
• could use -r "your/directory" to specify the data directory when init with init or run with node
  • the directory will be created if not existed

procedure

• need to build an account and an addr immediately after u init the node, otherwise, the rewards will be sent to an empty addr
• currently bytom doesn't support specifying the receive addr for rewards, and will use a same one by default
• API doc
• the pool /get-work-json from a node
  • need to set-up mining address in advance, using /set-minining-address
• send jobs to miners
  • as for the protocol, https://github.com/HAOYUatHZ/B3-Mimic/blob/master/docs/STRATUM-BTM.md can be helpful
    • a miner will only receive a job by login or by being notified by the pool
      • both use submit to submit
      • a miner will not getjob actively
  • a mock B3 miner: https://github.com/HAOYUatHZ/B3-Mimic/blob/master/main.go
    • Version, Height, Timestamp, Bits are little-endian
    • about target
      • .

        var Diff1 = StringToBig("0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF")
        
        func GetTargetHex(diff int64) string {
            padded := make([]byte, 32)
        
            diffBuff := new(big.Int).Div(Diff1, big.NewInt(diff)).Bytes()
            copy(padded[32-len(diffBuff):], diffBuff)
            buff := padded[0:4]
            targetHex := hex.EncodeToString(Reverse(buff))
            return targetHex
        }
        

      • targethex sent from the pool is target1（0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF） divided by the poolDiff, which is adjusted dynamically in order to ensure a miner submitting shares periodically, e.g., 3 times per minute
        • ffff3f00 is corresponding to 1024，c5a70000 is corresponding to 100001
  • the pool need to validate the share
    • header_hash
      • can take advantage of types.BlockHeader{}'s Hash() in "github.com/bytom/protocol/bc/types" if using golang
      • https://github.com/HAOYUatHZ/B3-Mimic/blob/master/docs/blhr_hash_V3.go can be helpful if using other language
    • then follow the tensority algo to calc the hash result
      • unfortunately the verification speeds of gonum version, cpp_openblas version, cpp_simd version are all too slow
      • a working pool has to use gpu
        • cpp tensority, this repo also points out how to opt it using gpu
  • if a block is mined, the pool /submit-work-json to a node
• retarget
  • see above, asjusted dynamically to make a miner submit 3 times / min

batch tx

• the addr for mainnet starts with bm
  • length:
    • normal: 42
    • mul-sig: 62
• tool
  • https://github.com/Bytom/bytom/tree/master/tools/sendbulktx
• a new addr for change will be generated each time