Is max-old-space-size overridden (investigating a memory leak)?

[anrxc]

Bug Description

I have a Linux 6.x.x server with 64GB of RAM. Docker version 28.3.0.

I deployed N8N v1.97.0 docker container + N8N worker docker container + N8N PostgresSQL container. Each container with 4GB resource limit defined in docker-compose.yml file.

N8N is completely empty, it has only been installed. After 7 calendar days server is without RAM and crashes. Server is rebooted, after 7 calendar days server is without RAM again and crashes.

Okay, but first of all every conversation about memory with Node.js seems to being with "max-old-space-size".

I declare the value in NODE_OPTIONS environment variable of docker-compose file, but N8N seems to override it to 32GB.

I modify /docker-entrypoint.sh to export NODE_OPTIONS="--max-old-space-size=4096" there, but N8N seems to override it to 32GB again.

I modify N8N package.json start command to "start:default": "cd bin && /usr/local/bin/node --max-old-space-size=4096 ./n8n", but N8N seems to override it to 32GB.

Finally I changed N8N binary it self, shebang line becomes #!/usr/bin/env node --max-old-space-size=4096 and this for once has an effect on node, but N8N refuses to start and just hangs in the process list.

Can you please provide us with a method to undeniably start node n8n with a custom --max-old-space size? No environment guesswork, no overriding, put it right there in the process list and do not freeze on startup?

Please. Thank you.

P.S. since I am on the topic, attempting to pass 2 or more node options via environment variables breaks N8N. For example:

- NODE_OPTIONS="--max-old-space-size=4096 --max-semi-space-size=64"
Error: illegal value for flag --max-old-space-size=4096 --max-semi-space-size=64 of type size_t

To Reproduce

1. git clone https://github.com/n8n-io/n8n-hosting/ && cd n8n-hosting
2. Insert "- NODE_OPTIONS=--max-old-space-size=4096" in docker-compose.yml file
3. docker-compose -f docker-compose.yml up -d
4. Wait 7 days until server crashes with 60GB of RAM consumed.

Expected behavior

Don't crash the server when you're a brand new install.

Operating System

Unknown, bundled with N8N docker image (Alpine?)

n8n Version

1.97.0

Node.js Version

Unknown, bundled with N8N docker image

Database

PostgreSQL

Execution mode

main (default)

[Joffcom]

Hey @anrxc,

Thank you for reaching out! We’ve received your issue and are looking into it. To help us track this internally, we’ve created a Linear ticket with the reference: "GHC-2902".

We’ll keep you updated as we make progress, but if you have any additional details or context to share, feel free to add them here - it’s always helpful!

Thanks for your patience and for bringing this to our attention.

[Joffcom]

Have you checked the memory usage of the n8n containers? I would assume if an n8n instance was just filling up memory we would have hundreds of reports of this so I suspect there is something else going on or there is something unusual in your configuration.

We have a tiny bit of info here on how to set max old space here: https://docs.n8n.io/hosting/scaling/memory-errors/#increase-old-memory we rely on the existing nodejs options and we don't change them.

[anrxc]

Hello if you can't provide a way to set max old space size without guessing can you put the statistics of one of these functions (I'm not sure which one of the two is correct one, excuse me) in the web interface for the Administrator so that we can see our limits are being set and respected?

process.memoryUsage();

v8.getHeapStatistics();

Thank you.

[Joffcom]

Hey @anrxc,

That would be a good feature request to make on the community support forum. For now as there isn't really a bug here for us I am going to close this.