@subhasishgoswami - this from provable.xyz:
In production on blockchain mainnets since 2015. We have processed more than 1 millions requests to date - and counting!
@oraclize-support is there any information on how many of them have been successfully served. Like a percentage score of how many requests were served successfully out of total requests recieved.
gasLimit we pass to provable_query, and I noticed something interesting. It seems that there has to be at least 15000 more gas passed than the __callback actually needs, otherwise the TX will fail due to "out of gas". I suspect this must be something that the caller, e.g. Provable enforces? Is this documented somewhere?
Hi @oraclize-support
i am calling provable_newRandomDSQuery, everything appears to work perfectly, however: the _result that comes back in the __callback seems to be the same every time:
https://ropsten.etherscan.io/address/0xd9eB0B9cC0b296D86547FE6c1466fcC16036894c#events
event log shows Request(id), then Response(id, result), whereresult = uint256(keccak256(abi.encodePacked(_result)))
We are following the example of https://github.com/provable-things/ethereum-examples/blob/master/solidity/random-datasource/randomExample.sol
2 replies
we would recommend having such checks in place whenever you interact with any external system which may depend on an external off-chain state @numeralz
specifically this time one of the Ledger devices which generates the proof got stuck (from our experience it can happen once or twice per year on average) so it had to be rebooted
@oraclize-support ive read above that its possible to have dynamic url get requests, this doesnt seem to be the case for me based on a LOT of testing. Im using https://github.com/provable-things/ethereum-api/blob/master/provableAPI_0.6.sol. I have tried building up the request dynamically:
bytes memory queryBytes = abi.encodePacked("json(", _coordinatorUrl, "/token/event/address/0x", toAsciiString(sender), "/transaction/", uintToString(id) , "/amount/", uintToString(amount), ").validated");
string memory queryString = string(queryBytes);
emit LogRequest(queryString);
if (provable_getPrice("URL") > address(this).balance) {
// Log the error
emit LogNewProvableQuery("Provable query was NOT sent, please add some ETH to cover for the query fee");
// Revert
revert();} else {
// Send request and get query id
bytes32 queryId = provable_query("URL", queryString);
// Log the query sent
emit LogNewProvableQuery("Provable query was sent, standing by for the answer...");
// Return the queryId
return queryId;}
LogRequest logs the correct query string but no call is ever made to my api. But when i take that SAME query string and hard code it like:
// Send request and get query id
bytes32 queryId = provable_query("URL", HARDCODED_queryString);
It works.... can you please help explain what I am doing wrong?
check_query tool here to check your string concatenation methods are resulting in the expected query string?
I have checked the link you suggested.
https://github.com/provable-things/ethereum-examples/tree/master/solidity/truffle-examples/url-requests
@nft1126 - from docs.provable.xyz:
The developer can send to Provable the application binary or the script, its dependency and the Dockerfile by creating an archive and uploading it to IPFS. The query expects as first argument the IPFS multihash of that archive, while the following arguments will be passed to the execution environment as environmental variables, making them accessible by the application.
If you examine some of the other computation-datasource-using examples here: github.com/provable-things/ethereum-examples , you'll see how the query takes an array of args, the first of which is theIFPShash of the computation archive you want to use, and the second is an array of arguments of your choosing, which args will be made available to the computation via environment variables.