Flood of connection errors and many processes spawned

[D3SL]

Sometime in the last two weeks I started getting the error Connection to server is erroring. Shutting down server. in VSCode's output window with varying frequency during coding sessions. Today while during a lag spike I took a look at the task manager and saw about 20 R terminal front-end processes each taking nearly 100mb of ram. When I killed each process I got an error in VSCode like this one:

[Error - 7:41:10 pm] Connection to server is erroring. Shutting down server.
[Error - 7:41:10 pm] Connection to server is erroring. Shutting down server.
[Error - 7:41:10 pm] Connection to server is erroring. Shutting down server.
[Error - 7:41:10 pm] Connection to server is erroring. Shutting down server.
[Error - 7:41:10 pm] Connection to server is erroring. Shutting down server.
[Error - 7:41:10 pm] Connection to server is erroring. Shutting down server.
R Language Server (18440) exited with exit code 1

I'm on Windows 10, using the latest versions of VSCode and the LSP extension, R 4.0.2, and languageserver 0.3.6

[renkun-ken]

Would you like to try with the latest development version of languageserver and see if the problem still persists?

[D3SL]

the R package or the vscode extension?

[renkun-ken]

https://github.com/REditorSupport/languageserver

[D3SL]

I've got it installed, it may be a bit before I know if it's working or not given there doesn't seem to be any consistent way to provoke the issue.

[D3SL]

Actually that was faster than I thought. I don't get the constant error messages now but whatever is causing an extreme runaway spawning of processes is even worse than before, I've got something like 3 full double-screens worth of these processes and sometimes they wind up taking up almost all free resources.

[renkun-ken]

Looks like it might be caused by the session pool? @randy3k @qinwf any idea why this could happen?

[D3SL]

In case it's relevant I do often have more than one VSCode window open, often with one of them SSHed into a remote machine, and generally just close my laptop to put it to sleep rather than save and shut down everything. Are there any further logs or dumps I can provide, or any test I can run for you?

[arnoudplantinga]

I'm having the same problem, both in Windows and when using SSH to access a Linux server.

[renkun-ken]

@D3SL @arnoudplantinga

Could you share the answers to the following questions?

1. Does it occur when you do not open a folder in VSCode but instead open a single R file?
2. Are you working with multiple workspace folders and open many files from different places outside the workspace folder?
3. Does it still occur if you write R_LANGSVR_POOL_SIZE=0 in your ~/.Renviron so that the session pools are disabled?

[D3SL]

1. Yes
2. Not sure what you mean by this, I just use "open folder" in VSCode. This happens whether or not I open a higher level folder and have multiple projects from various subfolders open at the same time or whether I open only one specific project's folder and subfolders. It also happens whether or not I'm SSHed into a remote machine or working locally only.
3. I just tried that and I still get 2 R For Windows front-end processes and 7 R For Windows terminal front-end the instant I create an R terminal

[D3SL]

Very late update but this appears to still be thing. I opened VSCode momentarily just to try this and instantly had 4 "R for Windows Front-end" processes and 8 "R for Windows Terminal Front-End" processes just from having a single R script open and R session created.

It's unfortunate because unlike the slower object or plot rendering and windows bracketed paste issue this is an actual showstopper, it eventually winds up eating all available ram and then I'm forced to kill the language server's processes.

[renkun-ken]

@D3SL Is it still eating all the memory if you put R_LANGSVR_POOL_SIZE=0 in your ~/.Renviron so that the session pools are disabled?

@randy3k I think we need to minimize the session pool if the machine does not meet a certain condition, e.g. at least 8 CPUs and 32GB RAM?

[D3SL]

Assuming it's using the .Renviron in Documents, which path.expand('~') says is my home folder, yes I put that in when you first suggested it last year. On the upside, it seems like those processes are actually cleaned up on closing VSCode now so I don't wind up with 200 of them like before. EDIT: One thing that is different, opening a single file can sometimes open just VSCode without all of the "console window host" and R for Windows/Windows Terminal front-end processes.

I'm not sure if they'll still grow out of control over time, I can go back to VSC instead of RStudio for a few dev sessions and see if it just stays parked at about this level of memory usage.