nodejs / nodejs/node

Implement parallel Happy Eyeballs as described in RFC 8305

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feature request net never-stale
Dominant language
JavaScript
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Avg merge
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Merged PRs (30d)
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Description

What is the problem this feature will solve?

autoSelectFamily is enabled by default in Node.js 20. However, it does not properly implement parallel connection attempts, which are an integral part of the Happy Eyeballs algorithm. This can cause timeouts to occur that did not occur in versions prior to Node.js 20. See, for example, this discussion.

What is the feature you are proposing to solve the problem?

Implement the algorithm as described in Section 5 of RFC 8305:

Starting a new connection attempt does not affect previous attempts, as multiple connection attempts may occur in parallel.

What alternatives have you considered?

Disabling autoSelectFamily and restoring the pre-20 behavior, see https://github.com/nodejs/node/issues/47644#issuecomment-1554440759.

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start with Section 5 of RFC 8305 and compare its parallel connection-attempt requirements with Node.js's current autoSelectFamily behavior. Use the linked discussion and the pre-20 behavior referenced in the issue to understand the regression; done means connection attempts can proceed in parallel without affecting earlier attempts and the reported timeout behavior is addressed.

Written by the indexing model from the issue text.

Assessment

Tech stack
javascript, nodejs
Domain
networking
Issue type
Feature
Difficulty
4/5
Estimated time
3-5 days
Activity status
Quiet
Clarity
Mostly clear
Newbie friendliness
48/100

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