9.28.1 introduces memory leak with sveltekit

[tehnrd]

Is there an existing issue for this?

• I have checked for existing issues https://github.com/getsentry/sentry-javascript/issues
• I have reviewed the documentation https://docs.sentry.io/
• I am using the latest SDK release https://github.com/getsentry/sentry-javascript/releases

How do you use Sentry?

Use sentry in frontend and backend application of sveltekit. This issue is effecting the backend nodejs build of sveltekit.

Which SDK are you using?

@sentry/sveltekit

SDK Version

9.30.0

Framework Version

@sveltejs/kit 2.22.0
nodejs v22.16.0

Link to Sentry event

No response

Reproduction Example/SDK Setup

I have provided a full repo and steps to reproduce here: https://github.com/tehnrd/sentry-mem-leak

I have also created a video here showing how to reproduce with the repo above: https://www.loom.com/share/144a1120862143378938b78cc7063b13?sid=225abc0f-f229-4887-81d7-1386acb94b72

From AWS when upgraded from 9.27.0 to 9.30.0:

Steps to Reproduce

With this repo:

• Update @sentry/sveltekit to "9.28.1" or higher in package.json
• Run npm i to update the dependencies.
• Run npm build to build the server code.
• Run npm start to start the custom express server
• Open chrome memory inspector in Chrome Broswer: chrome://inspect/#devices
• Select inspect link to open the inspector for the server.
• Select the Memory tab if not already selected.
• Select "Allocations on Timeline"
• Select the Start button
• Run the npm ab command to start a simple Apache Bench GET request loop to the server.
• Monitor the memory usage in the timeline and note it is growing and not being cleared out.

Expected Result

Memory usage should not continue to increase.

Repeating steps above with @sentry/sveltekit 9.28.0 there is no leak.

Actual Result

Memory usage starts to increase and is never freed up.

[teemingc]

In @sveltejs/kit 2.21.3 we started bundling packages that specified SvelteKit as a dep/peer dep sveltejs/kit#13843 we plan to revert this change in sveltejs/kit#13894 . For now, you can add @sentry/sveltekit to your vite.config.ts file's ssr.external setting and it should undo this change as well and see if that helps with the memory leak.

[s1gr1d]

Thanks @eltigerchino for giving context on this. @tehnrd Please comment if setting it external helped.

[tehnrd]

I've added @sentry/sveltekit to ssr.external but the leak still persists.

https://github.com/tehnrd/sentry-mem-leak/blob/main/vite.config.ts

import { sveltekit } from '@sveltejs/kit/vite';
import { defineConfig } from 'vite';

export default defineConfig(() => ({
	plugins: [sveltekit()],
	ssr: {
		external: ['@sentry/sveltekit']
	}
}));