[WIP] CRaC POC

[danielkec]

Helidon MP on CRaC

Coordinated Restore at Checkpoint

Helidon MP Implicit example on CRaC

examples/crac/README.md

mvn clean package
docker build --build-arg CR_DIR=~/cr -t crac-helloworld . -f Dockerfile.crac
# First time ran, checkpoint is created, stop with Ctrl-C
docker run --privileged -p 7001:7001 --name crac-helloworld crac-helloworld
# Second time starting from checkpoint, stop with Ctrl-C
docker start -i crac-helloworld