Module OpenJDK PlayGround

Install OpenJDK

$ curl -s "https://get.sdkman.io" | bash
$ sdk i java openjdk-ea-21

Build

$ ./gradlew build

Run with preview features enabled

$ java -jar \
       --enable-preview \
       --add-modules=jdk.incubator.concurrent \
       -XX:+UseZGC \
       build/libs/openjdk-playground-*-uber.jar

# Virtual thread debugging.
$ jfr print --events jdk.VirtualThreadPinned openjdk-playground.jfr
$ jcmd dev.suresh.Main Thread.dump_to_file -format=json openjdk-playground-threads.json


# Check the incubator modules
$ java --list-modules | grep -i incubator

Run the application container

$ ./gradlew jibDockerBuild
$ docker run -it --rm --name openjdk-playground sureshg/openjdk-playground

Load testing the Web Server

• Check if the service is up and running!

  $ curl -v -k https://localhost:8443

• Set the os ulimit for Vegeta

  $ ulimit -n 4096 // FD limit
  $ ulimit -u 1024 // processes limit

• Run with kernel threads.

  $ echo "GET https://127.0.0.1:8443/" | vegeta attack -insecure -duration=10s -name=Threads -rate=250 | tee thread-results.bin | vegeta report
  $ vegeta report -type=json thread-results.bin > thread-metrics.json
  $ cat thread-results.bin | vegeta report -type="hist[0,100ms,200ms,300ms]"
  $ cat thread-results.bin | vegeta plot -title "Normal Threads" > plot.html && open plot.html

• Run with Virtual threads.

  $ echo "GET https://127.0.0.1:8443/" | vegeta attack -insecure -duration=10s -name=VirtualThreads -rate=250 | tee vthread-results.bin | vegeta report
  $ vegeta report -type=json vthread-results.bin > vthread-metrics.json
  $ cat vthread-results.bin | vegeta report -type="hist[0,100ms,200ms,300ms]"
  $ cat vthread-results.bin | vegeta plot -title "Virtual Threads" > plot.html && open plot.html

• Combine the results and plot a single graph.

  $ vegeta plot -title "Threads vs Virtual Threads"  vthread-results.bin thread-results.bin > plot.html && open plot.html

Troubleshooting

• Test Report
• Coverage Report

Commands

# Check the current version
$ ./gradlew -q --console plain version

# Publish to local repository
$ ./gradlew publishMavenPublicationToLocalRepository

# Stop Gradle and Kotlin daemon
$ ./gradlew --stop && pkill -f KotlinCompileDaemon

# Runs all checks
$ ./gradlew clean check

# Check tasks dependencies
$ ./gradlew clean build --dry-run

# Dep version updates
$ ./gradlew clean dependencyUpdates

# List all available toolchains
$ ./gradlew -q javaToolchains

Resources

• 🔌 Intellij Platform Explorer
• 🌲 Maven Deps Tree