Weird error under load

[roderik]

Error: invalid data for function output and the reason is undefined.

I think it might be a timeout or something, but I'm unsure how to even track this down.

{ error: { Error: invalid data for function output (arg="data", errorArg=undefined, errorValue=undefined, value="0x000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000000336469643a64656d6f3a706861726d617061636b3a363638323830303330303203f15cd7d5046041ce9f2b7feda8d8717542d57500000000000000000000000000", reason=undefined, version=4.0.27)
22/05/2019 18:09:35       at Object.throwError (/srv/node_modules/ethers/errors.js:76:17)
22/05/2019 18:09:35       at _FunctionDescription.decode (/srv/node_modules/ethers/utils/interface.js:98:20)
22/05/2019 18:09:35       at /srv/node_modules/ethers/contract.js:174:45
22/05/2019 18:09:35       at processTicksAndRejections (internal/process/task_queues.js:86:5) reason: undefined, code: 'INVALID_ARGUMENT', arg: 'data', errorArg: undefined, errorValue: undefined, value: '0x000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000000336469643a64656d6f3a706861726d617061636b3a363638323830303330303203f15cd7d5046041ce9f2b7feda8d8717542d57500000000000000000000000000' } }
22/```

[ricmoo]

Can you provide more context? And some code that causes this? :)

[roderik]

The code does not really help I'm afraid. The service throwing this (sporadically) is a microservice that mirrors all public methods of an ABI with no inputs to the database. It connects to two load balanced Parity nodes.

The code has been working fine for months, and currently, as well, it is just that "sometimes" (annoying, I know) and as far as I can tell not for the same contract each time, it throws this error.

I do know that the nodes are under some load, and doing truffle migrations every now and again I also get Error: Invalid JSON RPC response: "", known as, node is overextended.

Since everything is undefined, I'm guessing that for the same reason it gets back either a gateway error on request, with maybe even some HTML returned from an error page.

• I wonder if it would be possible to get Ethers to log the RPC response?
• And I'm unsure what the value in the error message is, is that the actual response? That would mean that the request succeeded and there is an issue decoding that data?

[ricmoo]

In v4 you can do provider.on(“debug", (info) => { }) which will log all requests. I think v5 logs both requests and responses to that event; if not I’ll make sure today that it does. :)

[roderik]

Ok, adding that in, let's see where it gets us! using v4, any reason to upgrade to v5 yet?

[ricmoo]

V5 is very unstable I’m fixing an issue where contract evens cause errors right now. Unless you consider instability a feature, I would stick with v4 unless you need a v5 feature. :)

[roderik]

hehe ok, will keep on v4 :)

[ricmoo]

Did you ever find out more about the cause of this?

[roderik]

Yes, but for the life of me I cannot remember. Searched the git log but no dice.