POA Forum

I have Hash, but transaction does not exists

Hi! I use nethereum (C# lib) to register a transaction in Poa Network.

Some records, go OK, but some without a defined pattern, return HASH without any error to me but the record does not exist.

for example: https://blockscout.com/poa/core/search?q=0x7c4da348f1de25d73ac3cb9aa1f6888855f4fcc885553d604b7ea77c3c085130 (404 Page Not Found)

Can you help me try to at least find the way?


Hi, could you provide a piece of code how do you broadcast a transaction to POA chain with Nethereum?

Hi Viktor!

Follow my code…

Doing some tests, it is happening when I send a batch of many records at the same time, the transactions are synchronous, but it takes less than 1 second to execute. Then after a while he starts to give the problem.

var abi = (new WebClient()).DownloadString(System.Configuration.ConfigurationManager.AppSettings["BlockChainContractSchemaUrl"]);
            var url = System.Configuration.ConfigurationManager.AppSettings["UrlNetWork"];

            KeyVault vault = new KeyVault();

            var privateKey = "";

            if (Key == null || Key == "")
                privateKey = vault.GetSecret("SenderAddressPrivateKey");
                privateKey = Key;

            var account = new Account(privateKey);
            var web3 = new Web3(account, url);

            var contractAddress = System.Configuration.ConfigurationManager.AppSettings["ContractAddress"];
            var senderAddress = System.Configuration.ConfigurationManager.AppSettings["SenderAddress"];
            var _set = new SetValue()
                dataValue = Message

            var contract = web3.Eth.GetContract(abi, contractAddress);

            var SetFunction = contract.GetFunction("set");

            byte[] ba = Encoding.Default.GetBytes(Message);
            double lenght = 8000000;

            var transactionHash = await SetFunction.SendTransactionAsync(senderAddress, new HexBigInteger(Convert.ToInt64(lenght)), new HexBigInteger(Convert.ToInt64(System.Configuration.ConfigurationManager.AppSettings["WeiGasPrice"])), new HexBigInteger(0), Message);

What is the gas price setting System.Configuration.ConfigurationManager.AppSettings["WeiGasPrice"]) ? Take into account that some validators increased the gas price recently on POA Core network https://forum.poa.network/t/increase-gas-price-from-1-gwei-to-5-gwei-to-mitigate-ongoing-resource-wasting-attack/3232

I can’t see the link. Appears as private.

But, i change GWEI from 1 to 10… the same problem :frowning:

Request OK with 10 GWEI

Request not found with 10 GWEI

best regards!

@Marcelo_Fernandes could you try sending txs asynchronously?

Hi Viktor,

The problem for sure is the fact that you send many transactions in a row at the same contract or address of origin.

I added a 30 second delay to each transaction… a day has passed and the problem has not happened anymore.

Is this a real fact? Does the network have any detection to understand that it could be an attack, for example?