[Ethereum] Getting “replacement transaction underpriced” though not trying to replace a transaction

infurarinkebytransactionsweb3js

I'm running an airdrop script which essentially loops a database of recipients and invokes a batchTransfer function each time with 80 different recipients and amounts.
After about 10 successful submissions, each new submission is rejected with "replacement transaction underpriced" – though the data of the request is different!
The stack is web3|infura|rinkeby

I read the answer here but not sure it applies. Will changing the nonce solve it? Where do I do it anyway? is nonce a param I add to the json array along with gas and gasPrice? And anyway, why doesn't the network see the data is different in each transaction I try to submit?

Best Answer

You can indeed change the nonce by hand; it is a transaction parameter and it goes alongside gas, gasPrice, value.

So your script can simply increment it then fire and forget the transaction.

Now, you need to find out the nonce value of the first transaction you fire. Easy: var firstNonce = web3.eth.getTransactionCount(yourSender);.

Edit:

Infura servers are at different states, so if your script calls web3.eth.getTransactionCount behind the scenes, it will get different results. Your script needs to keep track of the incrementing nonce and only call getTransactionCount once.

Related Solutions

[Ethereum] error: replacement transaction underpriced

I have been running into this issue as well. The network thinks you are trying to replace an existing unmined transaction. There are two ways to avoid this:

Adding a gas price %10 higher than the existing unmined transaction's gas price.
Increase your nonce to one higher than the unmined transaction.

I have also been getting this error:

"Transaction was not mined within 50 blocks, please make sure your transaction was properly send. Be aware that it might still be mined!"

In my case, I think the transaction is getting stuck in limbo somehow. It's not being mined by anyone, but it's not being removed from the pool of unmined transactions. Keep in mind that web3.eth.getTransactionCount(walletAddress) will only give you the last CONFIRMED nonce. So it won't take the unmined ones into account.

[Ethereum] Hash of the transaction VS Transaction Hash or Transaction ID

The transaction ID calculation is correct. For the signing, the arguments are still RLP encoded (the dummy "v" for EIP-155 is a bit special, see below).

Take this live transaction as an example. It has the following parameters.

nonce = 0 [RLP: 0x80]
gasPrice = 50000000000 wei (0x0BA43B7400) [RLP: 85 0BA43B7400]
gasLimit = 21000 (0x5208) [RLP: 82 5208]
to = 0x7917bc33eea648809c285607579c9919fb864f8f [RLP: 94 7917bc33eea648809c285607579c9919fb864f8f]
value = 1050000000000000 wei (0x03BAF82D03A000) [RLP: 87 03BAF82D03A000]
data = <empty> [RLP: 80]
v = 018080 (this is a place-holder value before signing, see EIP-155)

Then the input parameters for the hash is the RLP of the concatenation:

EB80850BA43B7400825208947917bc33eea648809c285607579c9919fb864f8f8703BAF82D03A00080018080

And the hash value for the signing is:

python3
>>> from Crypto.Hash import keccak
>>> keccak_hash=keccak.new(digest_bits=256)
>>> txn=bytearray.fromhex('EB80850BA43B7400825208947917bc33eea648809c285607579c9919fb864f8f8703BAF82D03A00080018080')
>>> keccak_hash.update(bytes(txn))
<Crypto.Hash.keccak.Keccak_Hash object at 0x10fb6e2e8>
>>> print(keccak_hash.hexdigest())

which gives the result

a4060d01d4add248db470b4121616cbe5b2015daf328809000ec9a1d0954d649

For the transaction ID, do Keccak hash on the final raw transaction bytes (RLP encoded as you mentioned, which are also readable from Etherscan) and it will give the same result as shown on Etherscan.

Best Answer

Related Solutions

[Ethereum] error: replacement transaction underpriced

[Ethereum] Hash of the transaction VS Transaction Hash or Transaction ID

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