This is an application demoing a clustered scheduler.
It exposes a REST API tasks to visualize the executed jobs which run every 10 seconds.
To compile and run this demo you will need:
- JDK 11+
- GraalVM
In addition, you will need either a PostgreSQL database, or Docker to run one.
Make sure that both the GRAALVM_HOME and JAVA_HOME environment variables have
been set, and that a JDK 11+ java command is on the path.
See the Building a Native Executable guide for help setting up your environment.
Launch the Maven build on the checked out sources of this demo:
./mvnw package
The Maven Quarkus plugin provides a development mode that supports live coding. To try this out:
mvn compile quarkus:dev
In this mode you can make changes to the code and have the changes immediately applied, by just refreshing your browser.
When you're done iterating in developer mode, you can run the application as a conventional jar file.
First compile it:
./mvnw package
Note that running this command will start a PostgreSQL instance and run the tests. To skip tests use the command below
./mvnw package -DskipTests
Next we need to make sure you have a PostgreSQL instance running (Quarkus automatically starts one for dev and test mode). To set up a PostgreSQL database with Docker:
docker-compose up postgres
Connection properties for the Agroal datasource, and Quartz are defined in the standard Quarkus configuration file,
src/main/resources/application.properties.
Then run the application with:
docker-compose up --scale tasks=2 --scale nginx=1
To start two instances of single instance of the application along side the nginx load balancer.
You can also create a native executable from this application without making any source code changes. A native executable removes the dependency on the JVM: everything needed to run the application on the target platform is included in the executable, allowing the application to run with minimal resource overhead.
Compiling a native executable takes a bit longer, as GraalVM performs additional
steps to remove unnecessary codepaths. Use the native profile to compile a
native executable:
./mvnw package -Dnative
After getting a cup of coffee, you'll be able to run this binary directly:
./target/quartz-quickstart-1.0.0-SNAPSHOT-runner
Please brace yourself: don't choke on that fresh cup of coffee you just got.
Now observe the time it took to boot, and remember: that time was mostly spent to migrate the quartz tables in your database.
Have fun, and join the team of contributors!