Terminal: Terminal gets extremely sluggish after a day of use

[lminer]

I'm finding that if I use Windows Terminal for more than a day, it starts to get extremely sluggish: there is a lag in opening and closing new tabs and a lag in switching between tabs and a lag in typing. This problem immediately resolves itself if I close the application and restart it.

I'm not sure how to give a more detailed bug report. I tried downloading WPR, but it errored out when I tried to make a recording.

My setup is as follows: I'm using the beta version of Terminal, running WSL2 with ubuntu 20.04. I'm on the insider branch of Windows 10 with CUDA support for WSL2 enabled. My laptop is a Razer Blade advanced 2019 4K with an nvidia 2080 mobile graphics card.

[zadjii-msft]

@lminer (or anyone else seeing this): A dump would be helpful in trying to find the root cause for this issue. You can capture one using Task Manager by right-clicking on WindowsTerminal.exe in the _Details_ tab. Thanks!

[mehgcap]

Just for the record, I'm seeing this as well. I opened a duplicate issue, not realizing this one was already here. I'll try
to capture a dump next time it happens.

[alexandermalfait]

@lminer (or anyone else seeing this): A dump would be helpful in trying to find the root cause for this issue. You can capture one using Task Manager by right-clicking on WindowsTerminal.exe in the _Details_ tab. Thanks!

Do you mean the "create dump file" option?

[zadjii-msft]

Yep, that one

[lminer]

How do I send it to you? The files are big

[alexandermalfait]

@zadjii-msft , you can download a dump file and a video showing the issue from this link: https://we.tl/t-Q9SG7e5z6r

Note that the dump file is 1GB uncompressed, which is a lot of memory usage for a terminal.

In task manager, I could see 700MB of memory usage, dropping to 70MB after restarting the terminal.

[mehgcap]

@zadjii-msft I can only get this to happen reliably when SSH-ed into a few work servers. In case the dump file contains potentially sensitive data, is there an email address where I can send it?

[djsavvy]

@mehgcap see https://github.com/microsoft/terminal/issues/7981 -- @DHowett provided an e-mail where you can send a dump.

[rebane2001]

I can confirm it as well, here's a GIF of me typing a sentence in a Windows Terminal vs just WSL

Usually, when using the Windows Terminal, I have a SSH session through WSL into a tmux session on a server. This server probably prints over a million lines of text a day, so my gut tells me that this data somehow gets stored in a cache/history of some sort that gets laggy once large enough. Of note is also that tmux sends a lot more data than a simple SSH session due to how it works. However, closing tabs does not solve this issue, I need to restart Windows Terminal for it to run fast again.

[alexandermalfait]

I've just had a (long overdue) 4 day holiday.

Coming back to my desktop session, Windows Terminal was extremely slow.
So the issue seems to "build up" even when WT is not being used at all.