Memory Leak when Handling 502 Errors

[astormnewrelic]

Describe the bug

We've discovered what appears to be a memory leak in axios when handling HTTP requests that result in a 502 error.

To Reproduce

1. Run this small program in a terminal window (sets up an endpoint to call)

2. Run the program whose source is provided below

   $ node main.js > /dev/null
   

3. Monitor memory usage of the node process from program Support file uploads #2

Expected Behavior: Memory usage stays constant

Actual Behavior: Memory use slowly grows over time

//File: main.js
const axios = require('axios')

// localhost:3001/bad
const client = axios.create({
  baseURL: 'http://localhost:3001'
})

const work = async () => {
  try {
    await client.get('/bad')
    console.log('did it')
  } catch (error) {
    console.log('an error')
  }
}

const main = () => {
  setInterval(work, 0)
}
main()

Expected behavior

We expect the memory use of the node process should stay consistent and not grow

Environment

• Axios Version 0.19.2
• Adapter: HTTP
• Node.js Version: v12.18.2
• OS: 10.14.6

Additional context/Screenshots

We maintain New Relic's NodeJS agent. We had a custom come to us reporting a memory leak in the Node Agent, with a reproduction here. Like a lot of the leaks reported to us, this appears to be a case of a small leak in an upstream package (axois) being made much worse by the steps the New Relic's Node Agent needs to take in order to instrument it's thing.

[chinesedfan]

Can you give full codes of main.js? Looks like it includes an express server. Then the memory leaking is hard to be determined by axios or express.

[astormnewrelic]

@chinesedfan Thank you for taking a look. Also -- d'oh -- my apologies. I appear to have copy and pasted the wrong program into my ticket description. I have pasted the actual reproduction into the description, and I will include it below as well.

const axios = require('axios')

// localhost:3001/bad -- 
const client = axios.create({
  baseURL: 'http://localhost:3001'
})

const work = async () => {
  try {
    await client.get('/bad')
    console.log('did it')
  } catch (error) {
    console.log('an error')
  }
}

const main = () => {
  setInterval(work, 0)
}
main()

This program isolates the problem so that axios is the only third party library in use.

[astormnewrelic]

@chinesedfan were you able to reproduce with the above program, or are you not seeing the problem we're seeing? Is there anything we can do to help move this along?

[chinesedfan]

I have a question about the example first, why you need setInterval with timeout=0. If you commented the line with axios, will its memory still keeps growing?

[astormnewrelic]

@chinesedfan If we comment out the axios line the memory will not keep growing, it stabilizes.

We're using setInterval in the above example to call the work function over and over again in order to show that the call to axios appears to be leaking memory in the thrown exception case. i.e. The best way to show it wasn't express was to remove express :)

Is there's a better way for us to demonstrate the memory leak for you? Please let us know and we'll be happy to assist.

[sammccord]

Seeing this as well, would love to see an update :)

[astorm]

@chinesedfan any updates on this or anything @sammccord and I could do to help move this along?

[chinesedfan]

Sorry, I don't have much experiences about memory leaking. There are some similar issues in our issue list. Hope the community can find out the reason with an easy understanding report.

[astorm]

Thank you @chinesedfan -- so if I understand you correctly in addition to seeing the behavior reproduced, you'll need someone that can actually get into the axios internals and describe what's going on that leads to the leak. @sammccord -- is that the sort of thing you might be up for?

[github-actions]

Hello! 👋

This issue is being automatically marked as stale because it has not been updated in a while. Please confirm that the issue is still present and reproducible. If no updates or new comments are received the issue will be closed in a few days.

Thanks.

[astorm]

Still present, still reproducible with the steps listed above.

[pgcalixto]

Hey, guys, I saw there has been recent updates on this issue (@astorm said it is still reproducible), I'd like to work on this. Is anyone else already tackling this problem?

[chinesedfan]

@pgcalixto Sure. Feel free to take it, as well as any other issues of axios. This repository requires help from the community urgently.

[jasonsaayman]

Please check if this has been fixed with #3694

[astormnewrelic]

Happy to check @jasonsaayman -- is that fix in a release yet? If not is there a canonical way to run axios from the master branch (is it enough to point NPM at the master branch of this repo, or is a build step required, etc?)

[jasonsaayman]

@astormnewrelic it seems that the error actually has to do with the follow-redirects package so the issue persists. To answer your question you can do the following npm install --save ../path/to/mymodule.