Prerequisite
Runtimes with CRaC support
CRaC has to be built into the Java runtime. The upstream builds, the vendor builds, and the criu permissions they need.
To use the CRaC functionality, you need a Java runtime that has support for CRaC integrated.
Runtimes differ in more than whether they have CRaC at all: the mechanism that takes the image is selectable, and which mechanisms a build offers is part of what you are choosing between. See checkpoint engines .
OpenJDK CRaC
The OpenJDK CRaC Project is developed in the GitHub repository github.com/openjdk/crac .
NOTE: The JDK archive should be extracted with sudo.
$ sudo tar zxf <jdk>.tar.gz
When using CRaC, if you see an Operation not permitted error, you may have to update your criu permissions with:
sudo chown root:root $JAVA_HOME/lib/criu
sudo chmod u+s $JAVA_HOME/lib/criu
Azul Zulu Builds of OpenJDK
Azul ships Zulu builds with CRaC integrated for Java 17, 21 and every feature release since, on Linux/x64 and Linux/Arm64, for both glibc and musl. These are the builds that take a real checkpoint.
Zulu builds with CRaC are also published for Windows and macOS, but for development only: there a checkpoint request is served by an immediate restore, without an image ever being written to disk. That is enough to exercise the CRaC code paths of an application on a laptop before it is deployed on Linux.
Note that the platform only limits where a checkpoint can be taken. An application compiled against org.crac
runs on any Java runtime, with or without CRaC support.
Azul’s builds also carry additions that are not part of the OpenJDK project, e.g. the warp engine, and those are documented at
docs.azul.com/crac
rather than on this site.
BellSoft Liberica JDK
DOWNLOAD LIBERICA JDK WITH CRAC
BellSoft publishes dedicated Liberica JDK builds with CRaC for Java 17 and 21, on Linux x86-64 and AArch64, as archives and as container images. They are documented at bell-sw.com .
Canonical builds of OpenJDK
Canonical packages CRaC-enabled OpenJDK in the Ubuntu archive, so it installs with apt and carries Ubuntu’s security maintenance. The source packages are openjdk-17-crac and openjdk-21-crac, in the archive since Ubuntu 24.10 and present in 26.04 LTS:
sudo apt install openjdk-21-crac-jdk
They install next to the regular openjdk-17 and openjdk-21 packages rather than replacing them, so a machine can have both. Canonical describes the wider set of builds at ubuntu.com/toolchains/java
.
AWS Lambda SnapStart
MORE INFO ABOUT AWS LAMBDA SNAPSTART
AWS Lambda SnapStart is a performance optimization developed by AWS that can significantly improve the startup time for applications. This feature delivers up to 10x faster function startup times for latency-sensitive Java applications at no extra cost, and with minimal or no code changes.
Other runtimes with checkpoint/restore
Eclipse OpenJ9, which is the VM in IBM Semeru Runtimes, reaches the same
place by a different road. Its own feature is CRIU Support
,
enabled with -XX:+EnableCRIUSupport and driven by the openj9.criu API — but
OpenJ9 also implements the CRaC API on top of it, and publishes the
jdk.crac.management javadoc
to prove it. An application written against org.crac can therefore run there.
It is also what Open Liberty InstantOn
is built on, whose crac-1.4 feature
exposes org.crac to a Liberty application.
Alibaba Dragonwell carries CRaC in its Extended Edition, listed in its own release notes .
Neither is a drop-in for the builds above — the enabling switches, the editions and the supported platforms are the vendor’s own, and the vendor’s documentation is where those are kept right.