Limit Ethereum mining difficulty in a private blockchain

Question

I am creating a private Ethereum blockchain for the sake of transactions management and storage. I don't care about the consensus part, so I changed the difficulty in the genesis file to 0x1.

I also edited the consensus.go file located under the consensus/ethash/ directory, and built a custom geth binary to limit the growth of difficulty but with no luck. Here's what I changed exactly, I changed the CalcDifficulty() method implementation with the following:

func (ethash *Ethash) CalcDifficulty(chain consensus.ChainReader, time uint64, parent *types.Header) *big.Int {
  return big.NewInt(1)
}

The problem is that with every block, the difficulty is increased by one. I tried to change the return value to return big.NewInt(0) but I got an error saying panic: division by zero

I just want to limit the difficulty to 0x1 regardless of how many blocks the chain has.

Answer 1

I had this problem a year ago. The easiest solution is to only mine, when there are transaction in the pool. This would only increase the difficulty a little bit and so you have a fast test-network. As far as i know, ganache does exactly this.