We are developing an Ethereum based exchange. In our project, customers put their orders to send ETH or ERC20 tokens to others, and we currently do these transactions via our Ethereum account on their behalf. On issue that we faced with was pending transactions. In our first tests, we created some transactions after just some seconds, and found out while the previous transactions are processing (pending), other transactions will be kept pending too due to the previous transaction status and the nonce the previous one had. The message I receive in Etherscan:
There is a Pending txn with a lower account nonce. This txn can only be executed after confirmation of the earlier Txn Hash
Please help me to know is this result true in your mind and practices too? And if so, what is the solution to avoid this problem? Do we need to use multiple accounts or is there any other solution?