substratevm-netty-hello-world

Hello World HTTP Netty server running on SubstrateVM from the Graal project.

License

Apache 2.0

Obtain

The project is based on Maven.

Usage

Build SubstrateVM and get the labs JDK, then set JAVA_HOME

export JAVA_HOME=/usr/java/labsjdk1.8.0_161-jvmci-0.42/

Build this project using

mvn clean package

then compile the SubstrateVM native image using

native-image -cp ./target/substratevm-netty-hello-world-1.0.0-SNAPSHOT.jar com.github.skjolber.graal.netty.HelloWorld -Dio.netty.noUnsafe=true -Djava.io.tmpdir=/tmp

Then run

./com.github.skjolber.graal.netty.helloworld

and visit

http://localhost:8080

and observe response 'Hello World'.

Start a comparable 'classic' instance using the command

java -XX:+UseG1GC -Dio.netty.noUnsafe=true -Djava.io.tmpdir=/tmp -jar target/substratevm-netty-hello-world-1.0.0-SNAPSHOT.jar 8081

Performance / benchmark

Memory use

Compare the (approximate) memory use of the two using the command

ps -eo size,pid,user,command --sort -size | awk '{ hr=$1/1024 ; printf("%13.2f Mb ",hr) } { for ( x=4 ; x<=NF ; x++ ) { printf("%s ",$x) } print "" }' | grep 'helloworld|hello-world'

In this simple experiment, the SubstrateVM version seems to be using quite a lot less memory, especially before seeing any HTTP traffic.

CPU use

The CPU use seems to converge to approximately the same level. A more complex use-case would be better for measuring the differences, as this is mostly I/O-bound.

History

• 1.0.0: Initial version