Pylance using a lot of memory

[ale-dg]

Hi,

I was checking the activity monitor in my Mac these days and it always shows "Code Helper (plugin)" with over 1 GB of memory usage. When checking through the Terminal which process is it, it turns out it is Pylance the one which is using this much memory. This sometimes causes a lag in VSCode and, in my case, sometimes it crashes it.

Is there a workaround for it?

Thanks!

Best

[Dragon-GCS]

Same as you, I notice that when i update vscode 1.87, memory of process Code Help(Plugin) keep increasing when vscode lunched. Search pid by ps -ef|grep $pid, find the pylance (spwaned by Code Help(Plugin)), is eating my memory.

[bschnurr]

Thanks for logging an issue.
Please see https://github.com/microsoft/pylance-release/blob/main/TROUBLESHOOTING.md#filing-an-issue
For how to catching the log file.

If you can share a code sample or repo that reproduces the problem that would be best.

[ale-dg]

Hi @bschnurr ,

Thank you for your answer.

Not sure how to catch that log as it is not something I caught in VSCode but rather in the Activity Monitor from MacOS. As @Dragon-GCS mentioned, just catch the PID from the activity monitor and in the terminal shows which plug in is stealing so much memory and gets the machine hot as an oven, which in this case is Pylance.

I am not sure how often have you checked the main VSCode repo, but there have been a lot of issues reported where the he typing begins to lag (see microsoft/vscode-jupyter#15351, microsoft/vscode#206119, microsoft/vscode#206865,). Even though some of them point to Jupyter, the one that seems to not "dump" memory is Pylance (Code Helper (Plugin)), which always stays over 1GB.

Let me know if I can help with something else.

Thank you again for your help.

Best,

[heejaechang]

if your goal is reducing memory footprint over having more functionality available, then you can try these to turn off some expensive features in settings.json

"python.analysis.indexing": false,
"python.analysis.typeCheckingMode": "off",
"python.analysis.enablePytestSupport": false,
"python.analysis.inlayHints.pytestParameters": false,
"python.analysis.inlayHints.callArgumentNames": "off",
"python.analysis.inlayHints.functionReturnTypes": false,
"python.analysis.inlayHints.variableTypes": false,
"python.analysis.autoImportCompletions": false,
"python.analysis.useLibraryCodeForTypes": false,
"editor.semanticHighlighting.enabled": false,

this will turn off us from digging into third party packages to figure out (infer) types when the packages don't support type annotations. usually that's the one that cause us to load a lot of third-party modules into memory.

since your main scenario is notebook, some of this info could still be fetched from kernel if you have run your notebooks.

[bschnurr]

also for the logs you need to copy the output window. "Select "View: Toggle Output" from the command palette (Ctrl+Shift+P on Windows/Linux, Command+Shift+P on macOS), then select "Python Language Server" in the dropdown on the right."

[ale-dg]

Hi @heejaechang ,

Thank you for your help. I understand I can turn all those assistances off for the sake of memory, but it does not explain the lagging nor the amount of hints it pops when using it. Yet again I could just uninstall it and call it quits.

In addition to me, I see others filing similar issues here, and even more dramatic problems than mine (#5531)

This morning I switched back to VSCode 1.82.3, Jupyter v2023.8.1002501831, Pylance v2023.8.30 and it runs as smooth as it should. Pylance now "only" uses 712 MB (from 1.2GB last time I used the latest version) and uses only 19 threads (or 8.1% of the CPU, whereas before it was around 20%). I also see another user did this and it helped (#5377). I have even disabled the automatic updates since now I am afraid something will break if it updates and I have been delayed for far too long troubleshooting this.

@Dragon-GCS would you be able to help us retrieving the logs as @bschnurr suggests so they can analyse the problem, please? I would gladly do it, but I have downgraded all the packages. 😜

Thanks

Best

[heejaechang]

@ale-dg, it's good to know that with VSCode 1.82.3, Jupyter v2023.8.1002501831, Pylance v2023.8.30, things work smoothly. Can you also tell us which python extension version you are using?

By the way, I am not saying we are not trying to address the performance issue. We are trying to figure it out, but so far, we are not getting enough information to reproduce it ourselves. This kind of performance issue is best addressed with a live reproduction so we can dig deeper. (We are fixing the ones that we could reproduce or investigate if users provide us with their project).

For your case as well, if you can provide us with the repository, such as your workspace (or a demo project that shows the symptoms) that we can open ourselves and investigate, then we might be able to help you much better.

[heejaechang]

by the way, this (#5531) is different issue. that one is something is crashing (it could be us but not 100% sure from the info provided by the user) and creating core dump in the directory where pylance extension is installed.

if we are crashed, then we would expect core dump to be created in the executable folder (the folder vscode exe exists) not our extension folder where js files exist.

[ale-dg]

Hi @heejaechang

My apologies if I sounded too blunt, it wasn't my intention. Just trying to imply that if I turn off all the assistances, then there is not a case on holding to Pylance and just uninstalling it as soon as possible.

As of now, I can't share the notebook I am working on since it is a work-in-progress and it is not finished yet, and even so the file is quite heavy (38MB), so GitHub has its restrictions on it. What I can tell you is that the notebook has around 185 active coding cells and several markdowns (it's a deliverable, so the markdowns must be in there). As it's a data science project, naturally it has some DataFrames using pandas, some graphs using Matplotlib, Seaborn, Plotly and GeoPandas and I just began with some "light" machine learning using scikit-learn, everything with the latest releases as it is a new environment (see attached).

The Python extension version is v2024.2.1

Best

environment.yml.zip

[heejaechang]

hmm.. the enviroment.yml.zip link doesnt work. 404 error.

[ale-dg]

... weird... I just dropped it... now I've attached it...
environment.yml.zip