Web3j Contract Call Transaction - Always out of gas

Question

Playing around with Web3j, I set up a private, single-node blockchain with Geth using a genesis gas limit of 21 million.

I started a node with the following command:

geth --datadir ./geth/data --rpc --networkid 611234220438 --nodiscover --mine --minerthreads 1 --etherbase 0xda42738b67c0dca7a44e3601312b7e44a007e4d2 --targetgaslimit 21000000 --verbosity 3

When I deploy a contract (gas limit 1 million), everything works as expected. A little bit of ETH is taken out of my wallet and I can interact with the deployed contract. However, constant functions work. All non-constant transactions fail and consume all gas.

I am executing this contract function (Solidity 0.4.13):

function skip() {}

Here is the contract creation and transaction as confirmed by Geth logging:

Submitted contract creation

fullhash=0xb407cf8dcb79cca01bd7bf11fb2ed025f5316d978aef92f2373be290a389df50 contract=0x075abea5aae9997bbf83a4a7f03d57c5bad65303

Submitted transaction

fullhash=0xae6697b0ebf6754f2570433a57dea159c662d79f59ef9d820cda5ffeb83028a5 recipient=0xc7c1335a273a6ee519f5563357b93b3e365a74da

Here is the transaction receipt:

{
  "transactionHash":"0x43c42aee0e44df748b0b482240e79f1536df15196843a4f752083bda02a14b01",
  "transactionIndex":0,
  "blockHash":"0x86b599ac97879417c5ed3f96e8985e85e861774c010b340e50081fcb6b2248bf",
  "blockNumber":461,
  "cumulativeGasUsed":1000000,
  "gasUsed":1000000,
  "contractAddress":null,
  "root":"0x70b774d4d679210d1e88f0d8fc0d6f2e0aec457fe333d65515e6bf61de7e0ec6",
  "from":"0xd2b4519298938983586e09028a2ea302c667cf76",
  "to":"0x075abea5aae9997bbf83a4a7f03d57c5bad65303",
  "logs":[],
  "logsBloom":"0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
  "gasUsedRaw":"0xf4240",
  "transactionIndexRaw":"0x0",
  "blockNumberRaw":"0x1cd",
  "cumulativeGasUsedRaw":"0xf4240"
}

What might be going wrong? To me, it looks like the transaction might be failing, though I don't know why or how to tell.

Answer 1

It turns out this was a misunderstanding of how Web3j works. I was expecting Web3j to deploy my latest contract on every run, but instead it was deploying my contract from a binary-encoded String.

In the Contract class generated by web3j-maven-plugin:

static final String BINARY = "606060405234610000575b60008054600160a060020a03191633600160a060020a03161790555b5b6104b9806100366000396000f300606060405236156100675763ffffffff60e060020a6000350416630f656e2c811461006c578063189e(...)";

This string is your compiled contract, not some kind of checksum for the contract.sol file. Unless you regenerate the Contract class on every change, it will keep using the old version, which did not have a function skip defined. I discovered this by starting from scratch.

Hopefully, the Geth devs will add a contract function undefined error some time - that would have led me down the right path a lot sooner!

Answer 2

I don't know whether this is same as in your case but I was also facing the same issue and the problem was that I was giving the wrong parameter for --datadir parameter.

I fixed that and the problem was solved.

Answer 3

As you have mentioned that all non-constant transactions are failing and constant functions are working. I am suspecting this could be due to lack of default account.

Try to set the default account address or associate an account address to the transaction like below:

web3.eth.defaultAccount = web3.eth.accounts[0]

or

contract.function(param,{from: eth.accounts[0]}) 

or

contract.function(param,{from: 'Your account address'})