Multiple transactions submitted at the same time asked me to ask questions

Question

I submit two transactions at the same time, will be incorrect like that java.lang.RuntimeException: Error processing transaction request: known transaction: a025d1ff67ec0545aff341aba7d47f6d8fb8da6a5580422a42db8eb2a343083d

how to resolve it

Answer 1

This is probably because the nonce of the transactions are the same. Indeed, you send them at the same time. If they come from the same address and if you don't specify what nonce to use, it will take the nonce from the chain.

But in the chain, fro both transactions, the nonce will be the same because the previous transaction was not mined.

So the first transaction is ok (nonce is correct), not the second on won't work because there is already a tx with this nonce. (the one you sent just before)

Answer 2

1. You have to wait for mining first transaction and then submit the second.
2. You can send the first transaction from one account and second from another.