Everything in here is based on this repo: https://github.com/cstancu/netty-native-demo

Vert.x on GraalVM

To work this project needs a modified version of Vert.x which you can find here: https://github.com/codepitbull/vert.x

Clone the repo and then build the 3.5_graalvm branch. Build using mvn clean install -DskipTests. Skipping the tests is required as they are currently broken (removed SSL related code in a rather harsh way).

The build this project:

mvn clean package

This produces the required fat-jar.

Then follow Setting up the development environment from below.

Then run:

native-image -jar target/vertx-graalvm-full.jar -H:ReflectionConfigurationFiles=resources/netty_reflection_config.json -H:+ReportUnsupportedElementsAtRuntime -H:Name=vertx-graalvm

Now you got your binary: ./vertx-graalvm

============================= Original Docs

Instant Netty startup using GraalVM's Native Image Generation

The purpose of this repo is to walk you through generating a native executable image from a simple Netty application using the GraalVM native-image tool.

Setting up the development environment

To set up your development environment you first need to download GraalVM. Either the Comunity Edition or the Enterprise Edition will work for the purpose of this example. The GraalVM download contains a full JVM plus few other utilities like the native-tool. Then you need to set your JAVA_HOME to point to GraalVM:

$ export JAVA_HOME=<graalvm-download-location>/graalvm-1.0.0-rc1

Then you need to add GraalVM to your path:

$ export PATH=$JAVA_HOME/bin:$PATH

Now you can run the native-image tool:

$ native-image --help

GraalVM native-image building tool

This tool can be used to generate an image that contains ahead-of-time compiled Java code.
...

Alternativelly, you could build native-image from source following the quick start guide.

For compilation native-image depends on the local toolchain, so please make sure: glibc-devel, zlib-devel (header files for the C library and zlib) and gcc are available on your system. On the OS that this demo was tested, Ubuntu 16.04, the following command was required to install zlib-devel, the rest of the dependencies being installed out-of-the-box:

$ sudo apt-get install zlib1g-dev

Setting up the project

For the purpose of this demo we copied the HttpHelloWorldServer example from the netty examples repo.

The example is built with Maven. But before we build we need to install svm.jar in the local Maven repository since the projects pom.xml file depends on it. The svm.jar library contains all the code needed to compile the substitutions required for Netty.

$ mvn install:install-file -Dfile=${JAVA_HOME}/jre/lib/svm/builder/svm.jar -DgroupId=com.oracle.svm -DartifactId=svm -Dversion=GraalVM-1.0.0-rc1 -Dpackaging=jar

The other required library, graal-sdk.jar, is automatically added to the classpath when you run the javac command shipped with GraalVM.

Now you can build with:

$ mvn clean package

This will create a jar file with all dependencies embedded.

Run Netty on JVM

On the regular JVM you can run as usual using the java command:

$ java -jar target/netty-svm-httpserver-full.jar
Open your web browser and navigate to http://127.0.0.1:8080/

Run Netty with GraalVM Native

To build the native image we use the native-image tool:

$ native-image -jar target/netty-svm-httpserver-full.jar -H:ReflectionConfigurationFiles=resources/netty_reflection_config.json -H:Name=netty-svm-http-server
Build on Server(pid: 29456, port: 26681)
   classlist:     194.15 ms
       (cap):     468.11 ms
       setup:     626.51 ms
  (typeflow):   3,709.95 ms
   (objects):   2,402.43 ms
  (features):      42.58 ms
    analysis:   6,274.84 ms
    universe:     141.76 ms
     (parse):     310.85 ms
    (inline):     658.15 ms
   (compile):   1,782.15 ms
     compile:   3,055.74 ms
       image:     484.51 ms
       write:     132.26 ms
     [total]:  10,936.45 ms

This creates an executable file that is less than 9 MB in size:

$ ls -Gg --block-size=k netty-svm-http-server
-rwxrwxr-x 1 8330K May  8 23:33 netty-svm-http-server

We can now run the executable:

$ ./netty-svm-http-server
Open your web browser and navigate to http://127.0.0.1:8080/