warmup mode

[akosyakov]

It is originally raise in Gitpod: gitpod-io/gitpod#12448
For very big projects it takes a while to import and reindex the project on the startup of container. Gitpod has a concept of prebuild, i.e. CI for dev containers. We would like to warm up Java LS or VS Code extension that on real container start it is loaded immediately.

[OLibutzki]

Seems to be related to #2723 - created 18 hours ago, right?

[akosyakov]

IntelliJ has both shared indexes and warm up [1], i.e. warm up itself can be speeded up with shared indexes.

[snjeza]

I have tested the https://github.com/snjeza/spring-boot/tree/gitpod-vscode project.
Java LS downloads the project dependencies and builds the project when starting it for the first time. It takes 5+ minutes on my computer.
Java LS has its workspace at /workspace/.vscode-remote/data/User/workspaceStorage/<workspace_hash>/redhat.java/jdt_ws.
You can look at the Java LS server log with

tail -f /workspace/.vscode-remote/data/User/workspaceStorage/<workspace_hash>/redhat.java/jdt_ws/.metadata/.log

or
View>Command Palette>Java: Open Java Language Server log

If gitpod stops Java LS properly it will start quickly.

Case 1:

• close gitpod tab
• open it
  or
• close gitpod tab and stop the gitpod workspace
• open it
  or
• run Developer: Reload Window
  gitpod stops Java LS properly and Java LS saves its workspace.
  Java LS log:

!MESSAGE >> shutdown

!ENTRY org.eclipse.jdt.ls.core 1 0 2022-10-24 14:20:51.199
!MESSAGE >> exit

!ENTRY org.eclipse.jdt.ls.core 1 0 2022-10-24 14:20:51.802
!MESSAGE Shutdown received... waking up main thread

!ENTRY org.eclipse.jdt.ls.core 1 0 2022-10-24 14:20:51.809
!MESSAGE class org.eclipse.jdt.ls.core.internal.JavaLanguageServerPlugin is stopping:

Java LS doesn't rebuild the project and starts in several seconds.

Case 2:

• open the gitpod workspace in two tabs
  gitpod starts Java LS with a new Java LS workspace - /workspace/.vscode-remote/data/User/workspaceStorage/<workspace_hash>-1/redhat.java/jdt_ws
  Java LS rebuilds the project. It takes several minutes.

Case 3:

• stop the gitpod workspace using gitpod UI with opened project tab
• open it again
  gitpod doesn't stop Java LS gracefully.
  Java LS rebuilds the project.
  A solution: gitpod should stop VS Code as it does when closing the project tab.

[akosyakov]

@snjeza it is a bit another use case, Gitpod allow to configure prebuild of projects ahead of time: https://www.gitpod.io/docs/configure/projects/prebuilds It runs a headless workspace without VS Code to download dependencies, index and so on. We would like to run Java LS as part of it that when a user starts a new real workspace it looks like a restarted workspace in your example.

[snjeza]

@akosyakov could you provide an example?
I have tried to add (https://github.com/snjeza/spring-boot/blob/gitpod-vscode/.gitpod.yml)

tasks:
  - init: ./gradlew publishToMavenLocal

but VS Code starts before ./gradlew build -x test is finished.