Mandrel

Mandrel is a downstream distribution of the GraalVM community edition. Mandrel's main goal is to provide a native-image release specifically to support Quarkus. The aim is to align the native-image capabilities from GraalVM with OpenJDK and Red Hat Enterprise Linux libraries to improve maintainability for native Quarkus applications. Mandrel can best be described as a distribution of a regular OpenJDK with a specially packaged GraalVM Native Image builder (native-image).

How Does Mandrel Differ From Graal

Mandrel releases are built from a code base derived from the upstream GraalVM code base, with only minor changes but some significant exclusions. A full distribution of GraalVM is much more than native-image: it has polyglot support, the Truffle framework which allows for efficient implementation of interpreters, an LLVM compiler back end for native image, the libgraal JIT compiler as a replacement for Hotspot’s C2 server compiler and much more. Mandrel is the small subset of that functionality we support for the native-image use-case.

Mandrel's native-image also doesn't include the following features:

• The experimental image-build server, i.e., the --experimental-build-server option.
• The LLVM backend, i.e., the -H:CompilerBackend=llvm option.
• The musl libc implementation, i.e., the --libc=musl option.
• Support for generating static native images, i.e., the --static option.
• Support for non JVM-based languages and polyglot, i.e., the --language:<languageId> option.

Mandrel is also built slightly differently to GraalVM, using the standard OpenJDK project release of jdk11u. This means it does not profit from a few small enhancements that Oracle have added to the version of OpenJDK used to build their own GraalVM downloads. Most of these enhancements are to the JVMCI module that allows the Graal compiler to be run inside OpenJDK. The others are small cosmetic changes to behaviour. These enhancements may in some cases cause minor differences in the progress of native image generation. They should not cause the resulting images themselves to execute in a noticeably different manner.

Communication Channels

• Slack - Join #mandrel channel at graalvm's slack workspace
• graalvm-dev@oss.oracle.com mailing list - Subscribe here
• GitHub issues for bug reports, questions, or requests for enhancements.

Please report security vulnerabilities according to the Reporting Vulnerabilities guide.

Getting Started

Mandrel distributions can be downloaded from the repository's releases and container images are available at quay.io.

Prerequisites

Mandrel's native-image depends on the following packages:

• freetype-devel
• gcc
• glibc-devel
• libstdc++-static
• zlib-devel

On Fedora/CentOS/RHEL they can be installed with:

dnf install glibc-devel zlib-devel gcc freetype-devel libstdc++-static

Note: The package might be called glibc-static or libstdc++-devel instead of libstdc++-static depending on your system. If the system is missing stdc++, gcc-c++ package is needed too.

On Ubuntu-like systems with:

apt install g++ zlib1g-dev libfreetype6-dev

Building Mandrel From Source

For building Mandrel from source please see mandrel-packaging and consult Repository Structure in CONTRIBUTING.md regarding which branch of Mandrel to use.