Axios response memory leak

[Dirk94]

Describe the bug

I think that Axios has a serious memory leak. The Axios responses are never removed from memory.

To Reproduce

Create a new node project.

npm i axios && touch index.js

const axios = require('axios');

// Perform 1 request per second.
setInterval(async () => {
	const response = await axios.get("https://wikipedia.com");
	console.log("Done getting response!");
}, 1000)

Expected behavior

I would expect this program to not keep a reference to every response. But unfortunately, it does.

Environment

• Axios Version 0.21.0
• Node.js Version 14.12.0
• OSX 10.15.6

Additional context/Screenshots

The Chrome memory profiler shows that the Wikipedia responses are stored in memory.

[Legogris]

I have similar indications.

In node.js, after doing an axios.get(...).then(() => {...}), the process hangs indefinitely when it should exit.

If at exit point logging process.getActiveHandles(), the WriteStream, ReadStream and Socket are still hanging around long after the response has returned, the connection should be closed and the scope is out.

Same behavior when setting http(s)Agent with keepalive: false.

Nodejs 12 & 14, axios 0.19,0.20,0.21.1

[splitice]

I have been investigating a similar issue. I'm currently testing using a more robust script of:

const axios = require('axios'),
      Q = require('q-lite')

let request = 0
async function doRequest(url){
	request++
	try {
		await axios.get(url);
	} catch(ex){
		console.log(`${url}: Failed to get response ${request}`)
		return
	}
	console.log(`${url}: Done getting response ${request}`);
}

async function main(url){
	// Perform requests with a 1 second delay
	while(true){
		await doRequest(url)
		await Q.delay(1000)
	}
}

main("https://wikipedia.com")
main("https://google.com")
main("https://microsoft.com")
main("https://gmail.com")

Ran with: node --max_old_space_size=8 axios-leak.js

Your script is prone to memory build-up due to it not waiting on the response before starting the next. The number of requests in flight can increase if the request time increases.

I wasnt able to replicate any issue with my script, I tested up to 22,422 requests.

[splitice]

The following however does lead to an eventualy crash.

const axios = require('axios'),
      Q = require('q-lite')

let request = 0
async function doRequest(url){
	request++
	try {
		await axios.get(url, {timeout: 500});
	} catch(ex){
		//console.log(`${url}: Failed to get response ${request}`)
		return
	}
	//console.log(`${url}: Done getting response ${request}`);
}

async function main(url){
	// Perform requests with a 1 second delay
	while(true){
		await doRequest(url)
		await Q.delay(100)
	}
}

main("https://httpstat.us/200?sleep=5000")
main("https://httpstat.us/200?sleep=6000")
main("https://httpstat.us/200?sleep=7000")
main("https://httpstat.us/200?sleep=8000")
main("https://httpstat.us/200?sleep=5000")
main("https://httpstat.us/200?sleep=6000")
main("https://httpstat.us/200?sleep=7000")
main("https://httpstat.us/200?sleep=8000")
main("https://httpstat.us/200?sleep=5000")
main("https://httpstat.us/200?sleep=6000")
main("https://httpstat.us/200?sleep=7000")
main("https://httpstat.us/200?sleep=8000")
main("https://httpstat.us/200?sleep=5000")
main("https://httpstat.us/200?sleep=6000")
main("https://httpstat.us/200?sleep=7000")
main("https://httpstat.us/200?sleep=8000")
main("https://httpstat.us/200?sleep=5000")
main("https://httpstat.us/200?sleep=6000")
main("https://httpstat.us/200?sleep=7000")
main("https://httpstat.us/200?sleep=8000")
main("https://httpstat.us/200?sleep=5000")
main("https://httpstat.us/200?sleep=6000")
main("https://httpstat.us/200?sleep=7000")
main("https://httpstat.us/200?sleep=8000")
main("https://httpstat.us/200?sleep=5000")
main("https://httpstat.us/200?sleep=6000")
main("https://httpstat.us/200?sleep=7000")
main("https://httpstat.us/200?sleep=8000")
main("https://httpstat.us/200?sleep=5000")
main("https://httpstat.us/200?sleep=6000")
main("https://httpstat.us/200?sleep=7000")
main("https://httpstat.us/200?sleep=8000")
main("https://httpstat.us/200?sleep=5000")
main("https://httpstat.us/200?sleep=6000")
main("https://httpstat.us/200?sleep=7000")
main("https://httpstat.us/200?sleep=8000")

Ran with: node --max_old_space_size=5 --trace_gc --gc_interval=5000 axios-leak.js

So it appears the leak is tied to timeouts or failed requests.

[splitice]

Further troubleshooting narrows it down to follow-redirects as memory leak slower / non existant with maxRedirects:0. It only occurs on failed requests, so my current feeling is that a reference is being kept alive due to incorrect setTimeout / abort handling.

[RubenVerborgh]

follow-redirects v1.13.3 fixes this

[jasonsaayman]

This has been fixed with #3694

[DjovDev]

Hey you guys sure this is fixed?

I thought I'd give Axios a try instead of the actual HTTP client of Nodejs, yet I see my ram jump skyhigh when retrieving 5mb responses from a backend server using a post command:

I call these functions sequentially. After one is finished the next starts. This always retrieves the same response with binary data of abount 5 megabytes.

My axios function:

const axios = require('axios').default;
const parseString = require('xml2js').parseString;

// post xml function
function xmlPost(body,host,port,callback) {   
    axios({
        method:'post',
        url: 'http://' + host + ':' + port,
        data: body,
        headers:  {
            'Content-Type': 'application/xml',
            'Content-Length': body.length
        }
    }).then(response => {
        parseString(response.data, function (err, result) {
            if (err) {
                callback('Tried to parse the following XML: ' + buffer + ' - ' + err)
            } else {
                callback(null,result)
                result = null
            }
        })
    })
}

When doing something 'similar' in the http library, my ram stays levelled.

const http = require('http')
const parseString = require('xml2js').parseString;

// post xml function
function xmlPost(body,host,port,callback) {   

    let postRequest = {
        host: host,
        port: port,
        method: "POST",
        headers: {
            'Content-Type': 'application/xml;charset=UTF-8',
        }
    }

    let req = http.request( postRequest, function( res )    {
        let requestError
        let buffer = "";
        res.on( "data", function( data ) { buffer = buffer + data; } );
        res.on( "end", function( data ) { 
            if (requestError) {
                callback(requestError)
            } else {
                parseString(buffer, function (err, result) {
                    if (err) {
                        callback('Tried to parse the following XML: ' + buffer + ' - ' + err)
                    } else {
                        callback(null,result)
                    }
                })
            }

        } );
    
    });
    
    req.on('error', function(e) {
        requestError = 'Got error while posting XML: ' + e.message
        console.log('Got error while posting XML: ' + e.message)
    });
    
    req.write( body );
    req.end(); 
}

[Samrat-Saha-Sammy]

Seems like the bugFix #3694 is merged to master on March 23, but still we got no version release after that.

[shaoxp]

i used 0.27.2 version to test @Dirk94's original test, it still have memory leakage.

[shaoxp]

I test all versions following .

the results show that memory usage will always increase, so there seems still memory leakage. can someone reopen this issue? do we have any quick workaround?

and I used the chrome inspect to investigate the reason. and find the main leakage resource is a string referenced by root.

[lptai]

I just upgraded to axios@0.27.2 still have memory leak. My use case is retrying on 429 status - rate limit exceeded error. The application is keeping restarted with memory leak error with axios retry

[vzkhrv]

I test all versions following

Can't reproduce on my own. Do u still have this leakage?

[yuvalbl]

Reproduced on v1.4.0
A new related issue opened - see #5641