redis-quickstart

Quarkus demo: Redis

This is a simple incrementing service using Redis command.

While the code is surprisingly simple, under the hood this is using:

• RESTEasy to expose the REST endpoints
• A Redis database; see below to run one via Docker
• ArC, the CDI inspired dependency injection tool with zero overhead

Requirements

To compile and run this demo you will need:

• JDK 11+
• GraalVM

In addition, you will need either a Redis database, or Docker to run one.

Configuring GraalVM and JDK 11+

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.

Building the demo

Launch the Maven build on the checked out sources of this demo:

./mvnw package

Note that running this command will start a Redis instance and run the tests.

Running the demo

Prepare a Redis instance

Make sure you have a Redis instance running. To set up a Redis with Docker:

docker run --ulimit memlock=-1:-1 -it --rm=true --memory-swappiness=0 --name redis_quarkus_test -p 6379:6379 redis:5.0.6

Connection properties for the Redis connection are defined in the standard Quarkus configuration file, src/main/resources/application.properties.

Live coding with Quarkus

The Maven Quarkus plugin provides a development mode that supports live coding. To try this out:

mvn quarkus:dev

In this mode you can make changes to the code and have the changes immediately applied, by just making a http request to the service.

Run Quarkus in JVM mode

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 this command will start a Redis instance to execute the tests. Thus your Redis containers need to be stopped.

Then run it:

java -jar ./target/quarkus-app/quarkus-run.jar

Have a look at how fast it boots.
Or measure total native memory consumption...

Run Quarkus as a native application

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/redis-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 generate the tables in your database and import the initial data.

Next, maybe you're ready to measure how much memory this service is consuming.

Exposed endpoints

• GET /increments
• GET /increments/{key}
• DELETE /increments/{key}
• POST /increments accepting {key:"key", value:int-value}
• PUT /increments/{key} accepting an integer representing the increment value