`FetchError: request to http://0.0.0.0:8000/graphql failed, reason: socket hang up`

[IgnisDa]

What version of Remix are you using?

1.7.3

Steps to Reproduce

I have a graphql server. Making a single request to it in loader or action works fine. But if I have multiple requests:

await graphqlSdk().getStuff();
await graphqlSdk().getStuff();

it fails with the following error:

FetchError: request to http://0.0.0.0:8000/graphql failed, reason: socket hang up
    at ClientRequest.<anonymous> (/workspace/node_modules/.pnpm/@remix-run+web-fetch@4.3.1/node_modules/@remix-run/web-fetch/src/fetch.js:111:11)
    at ClientRequest.emit (node:events:513:28)
    at Socket.socketOnEnd (node:_http_client:512:9)
    at Socket.emit (node:events:525:35)
    at endReadableNT (node:internal/streams/readable:1359:12)
    at processTicksAndRejections (node:internal/process/task_queues:82:21) {
  type: 'system',
  errno: 'ECONNRESET',
  code: 'ECONNRESET',
  erroredSysCall: undefined
}

Expected Behavior

The requests should succeed and my backend should receive 2 requests.

Actual Behavior

The first request succeeds but the second one does not.

[IgnisDa]

Update: it works fine if I use axios to make the requests.

[machour]

@IgnisDa could you provide a reproduction somewhere? Might be a problem with our web-fetch package

[IgnisDa]

@machour I am not able to reproduce it anywhere else. Can you give instructions on how to debug the web-fetch package? When I try to add a console.log in the file (that is shown in the error message above), I do not get any output.

[sergiodxa]

@IgnisDa try to create a repo with a simple Remix app reproducing the error, that way it would be possible to try it and debug it

[IgnisDa]

@sergiodxa As I said before, I am not able to reproduce it in a simple repository.

The error is occurring in this repository: https://github.com/IgnisDa/codefarem/tree/remix-issue

Could you take a look at the package.json if there are any dependencies that might change the behavior of the web-fetch package?

[zifahm]

I have the same error right now using fly in production, works fine in development

[zifahm]

can confirm changing from fetch to axios fixes the issue.

I'm quite confused why this would be a problem

[richardbann]

Having the same issue here. Will try to put together a minimal example. At the moment it seems like the issue is with web-fetch as simple node:http.request works fine.

[richardbann]

Manually setting the http.request option agent to false (in web-fetch) resolves this issue. So it has to do someting with the socket pool... (https://github.com/remix-run/web-std-io/blob/f715b354c8c5b8edc550c5442dec5712705e25e7/packages/fetch/src/request.js#L326)

[machour]

pinging @jacob-ebey since he worked on web-fetch

[richardbann]

Ok, this is probably a node 19 thing (nodejs/node#43522). @IgnisDa , @zifahm , can you confirm you are using >= node 19?
The default http agent now uses KeepAlive by default and it is not playing nicely with the manually set connection: close header. (https://github.com/remix-run/web-std-io/blob/f715b354c8c5b8edc550c5442dec5712705e25e7/packages/fetch/src/request.js#L302).
To verify you can set KeepAlive in the fetch call:

resp = await fetch("http://myserver.test", {
  headers: { connection: "keep-alive" },
});

Could you please check @IgnisDa , @zifahm ?
@jacob-ebey , please let me know if I should further investigate.

[zifahm]

@richardbann yup is using ENV NODE_VERSION=19.1.0

[zifahm]

hmm was using node:current in the docker container. now switched to node:lts-slim

[IgnisDa]

Can confirm headers: { connection: "keep-alive" } fixes it.