Default http[2s] server timeout is problematic

[ofrobots]

Today, Node.js http servers timeout and close the socket after 2 minutes. This means that if a request needs to do work that takes longer than 2 minutes to complete; the socket would be unceremoniously closed and the client will get an empty response.

$ curl localhost:8080
curl: (52) Empty reply from server

This is a common problem (search results) that users have to work-around (but most don't know about it). This is specially problematic in serverless environments where users may be doing non-interactive event processing (e.g. photo / image transcoding, uploading large datasets somewhere). Users have to know that this problem is possible and must adjust the timeout to make sure the service works correctly.

This is problematic for PaaS hosting providers where the best we can do is document to our users that timeout must be adjusted. This is specially a problem for serverless containers (e.g. Google Cloud Run).

IMO the default value should be removed:

• Node.js seems to be the only environment where this timeout exists. Here's comparable HTTP server code in Ruby, Python, Rust, Go and Node.js for a request that takes ~10 minutes of work. Only the Node.js example terminates the socket unceremoniously.
• The timeout value of 120sec was added very early on in the history of the Node.js project, but no clear rationale was articulated for why the timeout should exist.

I would like propose that we remove the timeout. I am working on a PR to do so. Alternatively, If there is strong reason for us to have a default timeout value, let's clearly articulate the reason, and at least provide environment knobs to allow e.g. Serverless hosts to configure a different default value.

Thoughts? Opinions?

/cc @nodejs/http @nodejs/http2

[ofrobots]

#27558 removes the default value on the master branch and has landed. It is a semver major change however. We still have the issue that for existing branches in service, we need a way for platform providers (e.g. serverless environments) to configure a proper default (no timeout) and not have to depend on users knowing and working around this limitation.

I propose that we add an environment variable (NODE_DEFAULT_HTTP_SERVER_TIMEOUT) to allow the default value (2mins) to be overridden, but only on the currently supported branches (i.e. not on master). I am working on a PR to do this.

[ofrobots]

To elaborate, it would be simpler to add the environment variable across all branches, but that has the following downsides:

1. We will need to keep around this environment variable forever; even though the underlying problem has been fixed on master.
2. The environment variable may be perceived to set precedent for configuring arbitrary knobs (various timeouts, heuristics) through the environment.

[richardlau]

@ofrobots Does it need to be its own environment variable? It could be a command line option that could be allowed under NODE_OPTIONS?