Spring Boot, JVM and CRaC

This is a sample project to demonstrate Spring Boot 3.2+ CRaC support by creating a checkpoint and then restoring your application using it.

Step 1: Prerequisites

• Download JDK 17 with CRaC support provided by Azul From here and install it. This one is for Debian based OS like Ubuntu.

sudo dpkg -i zulu17.58.25-ca-crac-jdk17.0.15-linux_amd64.deb

• Grant appropriate permissions for CRIU to be functional. Note that you need to be present in your java home directory of the JDK you downloaded in previous step.

sudo chown root:root ./lib/criu

sudo chmod u+s ./lib/criu

Step 2: Build

mvn clean package

Step 3: Deploy

/usr/lib/jvm/zulu-17-crac-amd64/bin/java -XX:CRaCCheckpointTo=./tmp_chkpoint -jar ./target/crac-demo-0.0.1-SNAPSHOT.jar

Step 4: Checkpoint

Find the PID of the running instance and use it to create an application checkpoint:

jcmd 189254 JDK.checkpoint

Step 5: Restore

Restore and bring your instance back up:

/usr/lib/jvm/zulu-17-crac-amd64/bin/java -XX:CRaCRestoreFrom=./tmp_chkpoint