Abstract:
With smart contracts, a wide range of applications can be implemented on blockchains. Ethereum stores smart contract byte code with the smart contract ad-dress so, the Ethereum Virtual Machine (EVM) can read and execute transactions correctly. All executed transactions (both successful and failed transactions) are stored on the platform permanently. Failed transactions are thrown by the EVM due to runtime errors and result in monetary waste. The waste from these transactions add up to around 2 million Ethers or $634.2 million. In this thesis, we propose Evitar, a warning algorithm for reducing Ethereum smart contract runtime errors, which has two mechanisms. First, Evitar proposes that users send transactions with
the maximum gas allowed to avoid Out of Gas errors. However, this results in an extremely high transaction fee when transactions fail. Second, Evitar analyzes transactions called to each method in smart contracts and marks a method as a method with a high failure rate if the number of failed transactions reaches Evitar’s threshold. This mechanism prevents users from sending and paying for transactions that are likely to fail. We run experiments to evaluate the performance of Evitar by replaying transactions in a private network. The results show that Evitar can reduce failed transactions up to 99.52% compared to sending under default behaviour in exchange for a reduction in successful transactions by 1.78%. The amount of gas used by Evitar is only one-tenth compared to sending under default behaviour. Sending transactions with the maximum gas in Evitar reduces Out of Gas errors by 99.25%. In addition, Evitar can save up to 15.04 GB (82.32%) of storage in the Geth default node and 50.09 GB (50.09%) in the Parity full archive node.
