Merge pull request #63 from EspressoSystems/ma/replace-tx-min-gas-price

Increment gas price with at least 10%

ethtxmanager/ethtxmanager.go

@@ -511,8 +511,17 @@ func (c *Client) ReviewMonitoredTx(ctx context.Context, mTx *monitoredTx) error
  return err
  }
 
- // check gas price
- if gasPrice.Cmp(mTx.gasPrice) == 1 {
+ // The gas price of a replacement transaction needs to be at least 10%
+ // higher. The computation adds 1 Wei to offset rounding errors from
+ // truncation.
+ minReplace := new(big.Int).Set(mTx.gasPrice)
+ minReplace.Mul(minReplace, big.NewInt(11))
+ minReplace.Div(minReplace, big.NewInt(10))
+ minReplace.Add(minReplace, big.NewInt(1))
+
+ // If the current suggested gas price is higher than the minimum replacement
+ // gas price update the gas price for re-submission.
+ if gasPrice.Cmp(minReplace) == 1 {
  mTxLog.Infof("monitored tx gas price updated from %v to %v", mTx.gasPrice.String(), gasPrice.String())
  mTx.gasPrice = gasPrice
  }