Memory leak

[simongray]

The Angular frontend appears to have a memory leak. Our installation keeps crashing as it's running out of memory even though it's completely idle and unused. After around of 2 weeks its Docker container reaches ~8GB of RAM on our server which is wild for some frontend code (not counting the other containers which are also part of the system).

I fixed this by limiting the container memory limit to 2GB and having it restart once it crosses this limit. However, it would certainly be great if it didn't feature a memory leak at all. The previous version of the CLARIN DSpace fork doesn't have one AFAIK.

[kosarko]

hi @simongray you might want to tweak the pm2 cluster options the defaults

dspace-angular/docker/dspace-ui.json

Lines 2 to 12 in 0a8b3ee

	"apps": [
	{
	"name": "dspace-ui",
	"cwd": "/app",
	"script": "dist/server/main.js",
	"time": true,
	"instances": "7",
	"exec_mode": "cluster",
	"node_args": "--max_old_space_size=1344",
	"max_memory_restart": "2G",
	"env": {"NODE_ENV": "production"}

the default starts 7 node/express processes and each (on its own) has a cap of 2G.

I would blame it mostly on Caching - this part of the app handles the SSR. Is it really idling?

That said I don't doubt there are memory leaks; but to give some sort of perspective we've been running b261513 in production it's been up for 4 weeks; docker stats shows mem usage just under 7GiB.

[milanmajchrak]

Hi @simongray
We have seen similar high RAM usage with the Angular frontend. In our deployments, we usually handle this by tuning dspace-ui.json.

A more conservative PM2 config would be:

{
  "apps": [
    {
      "name": "dspace-ui",
      "cwd": "/app",
      "script": "dist/server/main.js",
      "time": true,
      "instances": "4",
      "exec_mode": "cluster",
      "node_args": "--max-old-space-size=768",
      "max_memory_restart": "1G",
      "env": {
        "NODE_ENV": "production"
      }
    }
  ]
}

This reduces the number of Node workers and restarts each worker after it reaches around 1 GB RAM. This should keep the container memory usage much more bounded than the default setup.

This does not rule out a real memory leak, but it should prevent the container from growing as much as before.