Two Ways Gas Price Oracles Miss The Mark

摘要

Blockchain transactions compete for limited space in blockchain blocks. Miners prefer to include transactions with higher fees into new blocks. In the context of Ethereum, gas price price oracles predict fees such that transactions submitted at those fees make it into a block within a target delay. In practice, however, oracles are not accurate, which makes it difficult for distributed applications to operate predictable services in terms of price and performance.To understand oracle performance we define a new gas prediction accuracy metric. We demonstrate that oracles underprice transactions, causing them to miss the delay target, as well as overprice transactions, causing them to meet the delay target, but at a higher than necessary cost. We provide comparative analysis of five gas price oracles showing their relative accuracy, transaction accept rates, price stability, and discuss factors that influence oracle accuracy. We observe that the ETHGasStation oracle produces the most accurate and stable price predictions. For users that prefer to run their own oracle Web3.py provides comparable performance.