Quarkus

Supersonic Subatomic Java

Peter Palaga

@ppalaga

Peter Palaga

Senior engineer at Red Hat Middleware
- Red Hat Fuse on EAP (WildFly Camel)
- JBoss EAP (WildFly)
Author of
- srcdeps - source dependencies for Maven and Gradle
- Maven and Gradle plugins for .editorconfig

Agenda

7 ms demo
What is Quarkus
How it works
More demos

Demo

What is Quarkus

Quarkus

Quark - an elementary particle

us - the hardest problem in software

Toolkit

and

Framework

for writing Java¹ applications

¹⁾ and Kotlin

Based on

Existing standards

Servlet JAX-RS JPA, JDBC CDI Bean Validation Transactions Logging
	Fault Tolerance Health JWT Metrics	OpenAPI OpenTracing Reactive Messaging Rest Client

Libs and frameworks

you love and use today

Eclipse Vert.x	Hibernate	Resteasy	Apache Camel	Netty
Kubernetes	Jaeger	Prometheus	Apache Kafka	Infinispan

Unifies

Imperative

and

Reactive

@Inject
SayService say;

@GET
@Produces(MediaType.TEXT_PLAIN)
public String hello() {
    return say.hello();
}

@Inject @Stream("kafka")
Publisher<String> reactiveSay;

@GET
@Produces(MediaType.SERVER_SENT_EVENTS)
public Publisher<String> stream() {
    return reactiveSay;
}

Developer joy

Easy to start with
Live reload, a.k.a. dev mode
Maven or Gradle
Java or Kotlin

Container First

💾

Small size on disk

✓

Small container images

🚀

Fast boot time

✓

Instant scale up

🔬

Low RSS¹ memory

¹⁾ Resident Set Size

✓

More containers with the same RAM

Measuring memory

RSS = all RAM consumed by the process

$ ps -o pid,rss,command -p $(pgrep quarkus)
  PID   RSS COMMAND
11229 12628 ./target/quarkus-hello

Memory (RSS)

	Quarkus + GraalVM	Quarkus + OpenJDK	Traditional Cloud-Native Stack
REST	13 MB	74 MB	140 MB
REST+JPA	35 MB	130 MB	218 MB

Startup time

Modern frameworks use lazy initialization

"started" before all classes are initialzed

What matters:

Time to first request

Time to first request^1/2

@Path("/")
public class GreetingEndpoint {
    @GET @Path("/greeting")
    public String greeting(@QueryParam("name") String name) {
        System.out.println(System.currentTimeMillis());
        return "Hello " + name;
    }
    void onStart(@Observes StartupEvent startup) {
        System.out.println(System.currentTimeMillis());
    }
}

Time to first request^2/2

$ while [[ \
    "$(curl -s -o /dev/null -w '%{http_code}' localhost:8080/greeting)" \
       != "200" \
  ]]; do sleep .00001; done

$ echo $(($(date +%s%N)/1000000)) && target/*-runner
1552931436155
1552931436626
INFO  [io.quarkus] (main) Quarkus 0.11.0 started in 0.035s.
INFO  [io.quarkus] (main) Installed features: [cdi, resteasy, resteasy-jsonb]
1552931436637

$ expr 1552931436637 - 1552931436155
482      # Time to first request in milliseconds

Time to first request

REST

REST + JPA

How does it work?

Traditional app server

Hundreds of classes run only during the boot
Later unused
Still occupy memory

Annotation processors, XML parsers, management model

Quarkus:

Build time boot

As much work as possible done at build time

Annotation processing
Configuration parsing

Output: "recorded" "wiring" bytecode

Wiring code invocation

Decided by extensions

`static` initializer	OR	`main()`
preferred	OR	access to files, sockets, etc.

Build oriented container

Quarkus extensions

Needed for frameworks that hit GraalVM peculiarities
Code divided into build time and runtime
Same JVM in dev mode
New extensions welcome!

Two distinct things:

Graal compiler (AoT or JIT)
GraalVM - the polyglot VM

^{In this presentation:}

GraalVM

Graal compiler

SubstrateVM

AoT¹ compilation with GraalVM

¹⁾ Ahead-of-time (1/3)

AoT compilation with GraalVM

(2/3)

Static analysis
Closed world assumption
Dead code elimination:
classes, fields, methods, branches

AoT compilation with GraalVM

(3/3)

$ native-image -jar my-app.jar
$ ./my-app

🚀 Fast process start

🔬 Less memory

💾 Small size on disk

Limitations

Dynaminc Classloading

Deloying jars, wars, etc. at runtime impossible

JVMTI, JMX

+ other native VM interfaces

No agents

JRebel, Byteman, profilers, tracers, ...

JVMTI, JMX

+ other native VM interfaces

No Java debugger
GDB (GNU project debugger) still works
DWARF debug symbols
- Inserted only by GraalVM enterprise
- Allow stepping through your java code

Miscellaneous

Security Manager

Finalizers (deprecated anyway)

InvokeDynamic and Method Handles

Reflection

Requires registration via native-image CLI/API

@RegisterForReflection in Qarkus

Require registration via native-image CLI/API

Dynamic proxies
Resources
JNI, Unsafe Memory Access, ...

Static init

1/2

Build time OpenJDK instance:

Resolve classes, run all static initilizers
Take a snapshot of the produced heap
Store it in the executable

Static init

2/2

Downsides:

no file handles, sockets, threads

More Quarkus please!

Get started

$ mvn io.quarkus:quarkus-maven-plugin:0.11.0:create \
    -DprojectGroupId=org.acme \
    -DprojectArtifactId=quarkus-hello \
    -DclassName="org.acme.quickstart.GreetingResource" \
    -Dpath="/hello"
$ cd quarkus-hello
$ mvn package
$ java -jar target/*-runner.jar
INFO  [io.quarkus] (main) Quarkus 0.11.0 started in 0.729s.
INFO  [io.quarkus] (main) Installed features: [cdi, resteasy]

https://quarkus.io/get-started/

Native

$ export GRAALVM_HOME=...
$ mvn clean package -Pnative
$ ls -lh target/*-runner
-rwxrwxr-x. 1 ppalaga ppalaga 19M Mar 20 14:39 target/quarkus-hello-1.0-SNAPSHOT-runner
$ ./target/*-runner
INFO  [io.quarkus] (main) Quarkus 0.11.0 started in 0.005s.
INFO  [io.quarkus] (main) Installed features: [cdi, resteasy]

https://quarkus.io/guides/building-native-image-guide

dev mode

$ mvn compile quarkus:dev

https://quarkus.io/guides/getting-started-guide

Testing

@QuarkusTest runner

JUnit 4 or 5

$ mvn clean test

https://quarkus.io/guides/getting-started-guide#testing

Testing native

@SubstrateTest runner

$ mvn clean verify

https://quarkus.io/guides/building-native-image-guide.html#testing-the-native-executable

Discover extensions

$ mvn quarkus:list-extensions
...
[INFO] Available extensions:
...
[INFO]   * Hibernate ORM (io.quarkus:quarkus-hibernate-orm)
[INFO]   * Hibernate ORM with Panache (io.quarkus:quarkus-hibernate-orm-panache)
[INFO]   * Hibernate Validator (io.quarkus:quarkus-hibernate-validator)
...

https://quarkus.io/guides/maven-tooling.html

Add an extension

$ mvn quarkus:add-extension -Dextensions=hibernate-orm-panache

https://quarkus.io/guides/maven-tooling.html

Panache

Makes simple Hibernate ORM easy

@Entity
public class Person extends PanacheEntity {
    public String name;
    public LocalDate birth;
    public PersonStatus status;
}

https://quarkus.io/guides/hibernate-orm-panache-guide

Panache persist

// creating a person
Person person = new Person();
person.name = "Stef";
person.birth = LocalDate.of(1910, Month.FEBRUARY, 1);
person.status = Status.Alive;

// persist and delete
person.persist();
if (person.isPersistent()){
  person.delete();
}

https://quarkus.io/guides/hibernate-orm-panache-guide

Panache Queries

List<Person> allPersons = Person.listAll(); // all persons
Person p = Person.findById(personId); // specific person by ID
// living persons
List<Person> livingPersons = Person.list("status", Status.Alive);

// counting
int countAll = Person.count();
int countAlive = Person.count("status", Status.Alive);

// deleting
Person.delete("status", Status.Alive);
Person.deleteAll();

https://quarkus.io/guides/hibernate-orm-panache-guide

More Panache

Paging
Sorting
Simplified query language
Autogenerated DAO/Repositories

https://quarkus.io/guides/hibernate-orm-panache-guide

Quarkus wrap up

Good old Java
Good old standards and libs
Efficiency level of Go language

Makes Java the choice #1 for the cloud and serverless

Quarkus Links

Docs & guides: https://quarkus.io/
Quickstarts: github/quarkusio/quarkus-quickstarts
Stack Overflow tag: quarkus

Quarkus

Peter Palaga

Agenda

Demo

What is Quarkus

Quarkus

Toolkit

Framework

Existing standards

Libs and frameworks

Imperative

Reactive

Developer joy

Container First

Measuring memory

Memory (RSS)

Startup time

Time to first request

Time to first request1/2

Time to first request2/2

Time to first request

How does it work?

Traditional app server

Build time boot

Wiring code invocation

Build oriented container

Quarkus extensions

GraalVM

Graal compiler

SubstrateVM

AoT1 compilation with GraalVM

AoT compilation with GraalVM

AoT compilation with GraalVM

Limitations

Dynaminc Classloading

JVMTI, JMX

JVMTI, JMX

Miscellaneous

Reflection

More

Static init

Static init

More Quarkus please!

Get started

Native

dev mode

Testing

Testing native

Discover extensions

Add an extension

Panache

Panache persist

Panache Queries

More Panache

Quarkus wrap up

Quarkus Links

Time to first request^1/2

Time to first request^2/2

AoT¹ compilation with GraalVM