After vscode exit , the redhat java process still exists, and continue waste CPU and memory

$ ps aux | grep redhat
nomore            2902 186.8  2.9 37742680 957764   ??  R     8:37AM 1050:18.51 /Users/nomore/.vscode-insiders/extensions/redhat.java-1.14.2023010903-darwin-x64/jre/17.0.5-macosx-x86_64/bin/java --add-modules=ALL-SYSTEM --add-opens java.base/java.util=ALL-UNNAMED --add-opens java.base/java.lang=ALL-UNNAMED --add-opens java.base/sun.nio.fs=ALL-UNNAMED -Declipse.application=org.eclipse.jdt.ls.core.id1 -Dosgi.bundles.defaultStartLevel=4 -Declipse.product=org.eclipse.jdt.ls.core.product -Djava.import.generatesMetadataFilesAtProjectRoot=false -Dfile.encoding=utf8 -XX:+UseParallelGC -XX:GCTimeRatio=4 -XX:AdaptiveSizePolicyWeight=90 -Dsun.zip.disableMemoryMapping=true -Xmx1G -Xms100m -Xlog:disable -javaagent:/Users/nomore/.vscode-insiders/extensions/redhat.java-1.14.2023010903-darwin-x64/lombok/lombok-1.18.24.jar -XX:+HeapDumpOnOutOfMemoryError -XX:HeapDumpPath=/Users/nomore/Library/Application Support/Code - Insiders/User/workspaceStorage/b2b9611ae61f2d143bc2a6ea62844278/redhat.java -jar /Users/nomore/.vscode-insiders/extensions/redhat.java-1.14.2023010903-darwin-x64/server/plugins/org.eclipse.equinox.launcher_1.6.400.v20210924-0641.jar -configuration /Users/nomore/Library/Application Support/Code - Insiders/User/globalStorage/redhat.java/1.14.2023010903/config_mac -data /Users/nomore/Library/Application Support/Code - Insiders/User/workspaceStorage/b2b9611ae61f2d143bc2a6ea62844278/redhat.java/jdt_ws

$ ps aux | grep redhat
nomore 2902 186.8 2.9 37742680 957764 ?? R 8:37AM 1050:18.51 /Users/nomore/.vscode-insiders/extensions/redhat.java-1.14.2023010903-darwin-x64/jre/17.0.5-macosx-x86_64/bin/java --add-modules=ALL-SYSTEM --add-opens java.base/java.util=ALL-UNNAMED --add-opens java.base/java.lang=ALL-UNNAMED --add-opens java.base/sun.nio.fs=ALL-UNNAMED -Declipse.application=org.eclipse.jdt.ls.core.id1 -Dosgi.bundles.defaultStartLevel=4 -Declipse.product=org.eclipse.jdt.ls.core.product -Djava.import.generatesMetadataFilesAtProjectRoot=false -Dfile.encoding=utf8 -XX:+UseParallelGC -XX:GCTimeRatio=4 -XX:AdaptiveSizePolicyWeight=90 -Dsun.zip.disableMemoryMapping=true -Xmx1G -Xms100m -Xlog:disable -javaagent:/Users/nomore/.vscode-insiders/extensions/redhat.java-1.14.2023010903-darwin-x64/lombok/lombok-1.18.24.jar -XX:+HeapDumpOnOutOfMemoryError -XX:HeapDumpPath=/Users/nomore/Library/Application Support/Code - Insiders/User/workspaceStorage/b2b9611ae61f2d143bc2a6ea62844278/redhat.java -jar /Users/nomore/.vscode-insiders/extensions/redhat.java-1.14.2023010903-darwin-x64/server/plugins/org.eclipse.equinox.launcher_1.6.400.v20210924-0641.jar -configuration /Users/nomore/Library/Application Support/Code - Insiders/User/globalStorage/redhat.java/1.14.2023010903/config_mac -data /Users/nomore/Library/Application Support/Code - Insiders/User/workspaceStorage/b2b9611ae61f2d143bc2a6ea62844278/redhat.java/jdt_ws

[rgrunber]

Are you able to share the sample project on which this happened ? Based on the process statistics, the language server is running at 186.8% so it definitely looks like it's doing some kind of processing. Did you take some actions that led to this or did you just notice the process was still running afterwards ?

using vscode open https://github.com/eugenp/tutorials git repo in your local machine.
My machine is Mac Book pro, Intel I5 cpu with 32GB memory and 1TB SSD
with MacOS 12.1

[snjeza]

https://github.com/eugenp/tutorials contains 1125 eclipse projects. The process will exit after importing those projects.

[rgrunber]

I was able to reproduce this one.

rgrunber 119168 449 11.0 7570968 1773576 ? Sl 14:26 200:12 /home/rgrunber/.vscode/extensions/redhat.java-1.14.2023011003-linux-x64/jre/17.0.5-linux-x86_64/bin/java...

I imported the full folder. Note that even the README states to just import the module you're interested in rather than all of them, when working in an IDE. But for the sake of figuring this out we can import it all. There are some gradle modules detected, but I think this should be imported as a Maven project, so I selected that option when prompted. It takes a pretty long time to import, and in my case, the language server runs out of memory. Once i tried shutting down VS Code, and the language server eventually shut off as well (within the ~30s timeout we have set). However, in another case it failed to shut off.

So I think this might be a case of getting the language server to crash, and perhaps it just fails to respond afterwards. I think some more investigation is needed.

[snjeza]

Once i tried shutting down VS Code, and the language server eventually shut off as well (within the ~30s timeout we have set).

The ~30s timeout is an inactivity timeout. In this case, Java LS imports the projects, that is, it is active. It will exit after importing all projects.
See

• https://github.com/eclipse/eclipse.jdt.ls/blob/master/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/ParentProcessWatcher.java#L78
• https://github.com/eclipse/eclipse.jdt.ls/blob/master/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/ParentProcessWatcher.java#L143

We can introduce another timeout (5 minutes, for instance). It should shut off the server even if it is active.

[rgrunber]

It's worth noting that, if you just close the client while the import is happening (and the connection has been established), then the language server can still receive exit / shutdown requests which will bring down the language server as usual. The other mechanism is in vscode-languageserver-node : https://github.com/microsoft/vscode-languageserver-node/blob/release/client/8.2.0-next.3/client/src/common/client.ts#L1408-L1409 which shuts it down.