Watchservice requires high sensitivity on this system

[nunovieira]

In VSCode, when Community Server Connector starts, the output shows many lines like:

17:30:35.171 [unch RSP Server] WARN o.j.t.r.s.f.FileWatcherService:206 - Watchservice requires high sensitivity on this system. Unfortunately it isn't present and thus watching the filesystem is unreliable. Please use openjdk or a sun jvm to allow us to use high sensitivity.

I believe it's using openjdk 11.
What could be done to solve this?

[robstryker]

Can you list your operating system and other relevant details? Also it'd be good to verify what jdk it's actually using if possible.

[nunovieira]

macOS 13.2.1 with M1 Pro processor
openjdk installed via homebrew (brew install openjdk@11 and sudo ln -sfn /opt/homebrew/opt/openjdk@11/libexec/openjdk.jdk /Library/Java/JavaVirtualMachines/openjdk-11.jdk)

In VSCode settings:

    "rsp-ui.rsp.java.home": "/Library/Java/JavaVirtualMachines/openjdk-11.jdk/Contents/Home",

and the process is using that jdk:

  501 69876 69444   0 12:07   ??         0:09.98 /Library/Java/JavaVirtualMachines/openjdk-11.jdk/Contents/Home/bin/java -Drsp.server.port=9000 -Dorg.jboss.tools.rsp.id=redhat-community-server-connector -Dlogback.configurationFile=./conf/logback.xml -jar /Users/nuno/.vscode/extensions/redhat.vscode-community-server-connector-0.26.6/server/bin/felix.jar

I also have Zulu 8 installed, but doesn't look to be used here.

What more information do you need?

[robstryker]

There's not much you can do here. Openjdk does not have a watch service that responds to filesystem or operating system events at this time. The implementation is completely polling-based, and thus will be slower, and could potentially miss events if for example a delete-file and create-file both occur between poll events.

There's really not much I can do on my end to fix this. Writing a custom mac filewatcher service appears to be something that even openjdk is struggling with, so the odds that I can do better are very low ;)

[emmanuelrflores]

@robstryker, any other JDKs that can handle this? I tried using the JDK provided by the Language Support for Java by Red Hat extension, to no avail.

/Users/myuser/.vscode/extensions/redhat.java-1.42.0-darwin-arm64/jre/21.0.7-macosx-aarch64

What's curious is I created a VS Code Dev Container using UBI8, and I set the rsp-ui.rsp.java.home to use the Language Support for Java by Red Hat as well;

/home/${localEnv:USER}/.vscode-server/extensions/redhat.java-1.42.0-linux-arm64/jre/21.0.7-linux-aarch64/

I can load the container and run it on my MacBook M1 without getting this error. I suppose in this case it's because it's the VM and a different build, macosx-aarch64 vs linux-aarch64?

[emmanuelrflores]

Just fyi, I tried using Oracle's JDK too, /Library/Java/JavaVirtualMachines/jdk-24.jdk/Contents/Home and it gives the same error.

Per your comment above, OpenJDK still has open issues on how to implement this JDK-7133447 & JDK-8293067.

Was really hoping I could use this on my macOS, but will need to stick to the dev container. At the very least, those on my team who are on Windows or linux can utilize it.

[LuckyMagacian]

For fix this warning , you can edit felix config file in /.vscode/extensions/redhat.vscode-community-server-connector-0.26.21/server/conf/config.properties uncomment org.osgi.framework.bootdelegation=sun.,com.sun.,jdk.*