Micronaut and GraalVM:
The power of AoT
Iván López
(@ilopmar)

Iván López @ilopmar
Iván López (@ilopmar)

Iván López @ilopmar
GraalVM
- Substrate VM: compile Java applications to native binaries
- https://www.graalvm.org

Iván López @ilopmar
- Reflection (with config)
- Dynamic class loading (with config)
- Dynamic proxy (with config)
- Unsafe Memory Access (partially)
- Class initializers (supported)
- InvokeDynamic bytecode and method handlers (partially)
- Lambda (supported)
- Finalizers (not supported)
- Threads (partially)
Limitations

Iván López @ilopmar
- Framework for microservices in the JVM
- Ultra-lightweight & reactive (Netty-based)
- Java, Groovy & Kotlin
- Ahead of Time compilation (AoT)
- No reflection, no runtime proxies
- Fast startup
- Low memory footprint
- Natively Cloud Native
- GraalVM support (improved a lot in Micronaut 2.x)
Micronaut

Iván López @ilopmar
$ mn create-app basic-app
--features=graalvm
Create an application with GraalVM support

Iván López @ilopmar
$ mn create-app basic-app
--features=graalvm
Create an application with GraalVM support
Micronaut 2.2 (Gradle & Maven)

Iván López @ilopmar
$ ./gradlew nativeImage
$ ./mvnw package -Dpackaging=native-image
Create native-image
$ ./gradlew dockerBuildNative
$ ./mvnw package -Dpackaging=docker-native

Iván López @ilopmar
- Composable native-image.properties
How does it work?

Iván López @ilopmar
# inject/native-image.properties
Args = --allow-incomplete-classpath
-H:EnableURLProtocols=http,https
# http/native-image.properties
Args = -H:IncludeResources=META-INF/http/mime.types
# http-netty/native-image.properties
Args = --initialize-at-run-time=
com.sun.jndi.dns.DnsClient,io.netty.handler.ssl.ConscryptAlpnSslEngine,io.netty.handler.ssl.Je
ttyNpnSslEngine,io.netty.handler.ssl.ReferenceCountedOpenSslEngine,io.netty.handler.ssl.JdkNpn
ApplicationProtocolNegotiator,io.netty.handler.ssl.ReferenceCountedOpenSslServerContext,io.net
ty.handler.ssl.ReferenceCountedOpenSslClientContext,io.netty.handler.ssl.util.BouncyCastleSelf
SignedCertGenerator,io.netty.handler.ssl.ReferenceCountedOpenSslContext,io.micronaut.buffer.ne
tty.NettyByteBufferFactory,io.netty.handler.ssl.JettyAlpnSslEngine$ClientEngine,io.netty.handl
er.ssl.JettyAlpnSslEngine$ServerEngine,io.netty.handler.codec.http2.Http2CodecUtil,io.netty.ha
ndler.codec.http2.CleartextHttp2ServerUpgradeHandler,io.netty.handler.codec.http2.Http2ServerU
pgradeCodec,io.micronaut.http.netty.channel.converters.EpollChannelOptionFactory,io.micronaut.
http.netty.channel.converters.KQueueChannelOptionFactory,io.micronaut.http.bind.binders.Contin
uationArgumentBinder$Companion,io.micronaut.http.bind.binders.ContinuationArgumentBinder
Micronaut includes everything (I)

Iván López @ilopmar
@AutomaticFeature
final class HibernateFeature implements Feature {
@Override
public void beforeAnalysis(BeforeAnalysisAccess access) {
// other drivers...
registerIfPresent(access, "oracle.jdbc.OracleDriver",
Oracle8iDialect.class,
Oracle9iDialect.class,
Oracle10gDialect.class,
Oracle12cDialect.class);
}
}
Micronaut includes everything (II)

Iván López @ilopmar
private void handleOracle(BeforeAnalysisAccess access) {
Class<?> oracleDriver = access.findClassByName(ORACLE_DRIVER);
if (oracleDriver != null) {
registerAllIfPresent(access, "oracle.jdbc.driver.T4CDriverExtension");
registerAllIfPresent(access, "oracle.jdbc.driver.T2CDriverExtension");
registerAllIfPresent(access, "oracle.net.ano.Ano");
registerAllIfPresent(access, "oracle.net.ano.AuthenticationService");
registerAllIfPresent(access, "oracle.net.ano.DataIntegrityService");
registerAllIfPresent(access, "oracle.net.ano.EncryptionService");
registerAllIfPresent(access, "oracle.net.ano.SupervisorService");
ResourcesRegistry resourcesRegistry = getResourceRegistry();
if (resourcesRegistry != null) {
resourcesRegistry.addResources("META-INF/services/java.sql.Driver");
resourcesRegistry.addResources("oracle/sql/converter_xcharset/lx20002.glb");
resourcesRegistry.addResources("oracle/sql/converter_xcharset/lx2001f.glb");
resourcesRegistry.addResources("oracle/sql/converter_xcharset/lx200b2.glb");
resourcesRegistry.addResourceBundles("oracle.net.jdbc.nl.mesg.NLSR");
resourcesRegistry.addResourceBundles("oracle.net.mesg.Message");
}
initializeAtBuildTime(access,
"oracle.net.jdbc.nl.mesg.NLSR_en",
"oracle.jdbc.driver.DynamicByteArray",
"oracle.sql.ConverterArchive",
"oracle.sql.converter.CharacterConverterJDBC",
"oracle.sql.converter.CharacterConverter1Byte"
);
initializeAtRuntime(access, "java.sql.DriverManager");
}
}
Micronaut includes everything (III)

Iván López @ilopmar
Micronaut includes everything (IV)

Iván López @ilopmar
Micronaut includes everything (V)

Iván López @ilopmar
- @Introspected
- @TypeHint
- @ReflectiveAccess
- GraalTypeElementVisitor
-reflect-config.json
-resource-config.json (* Micronaut 2.0)
Support in Micronaut

DEMO

Iván López @ilopmar
Demo

Iván López @ilopmar
14 vs 140 MB
What about memory?

Iván López @ilopmar
- Create a native image takes a lot of time
- And it needs a lot of RAM
- GraalVM changes so fast (and they break things)...
- ...and so we do ;-)
- We used Travis for testing Micronaut (now Github Actions), but...
- ...Travis has a limit for RAM
- We needed another way...
So… how do we test this?

Iván López @ilopmar
- Scheduled jobs every hour (2.2.x / 2.3.x)
- Only run if new commits in Micronaut or GraalVM
- Compile GraalVM from source code (JDK8 & JDK 11)
- Also test GraalVM stable
- Create native images for test Micronaut applications
- Run native images and execute functional tests
- https://github.com/micronaut-graal-tests
- https://gitlab.com/micronaut-projects/micronaut-graal-tests
Tests using Gitlab CI

Iván López @ilopmar
- Basic application: DI, POJO serialization, reactive types, HTTP Client
- Cache
- Micronaut function
- Service discovery: Consul & Eureka
- Static resources & views: Handlebars, Thymeleaf, Freemarker, Velocity, Pebble
- Management & Metrics endpoints
- Distributed tracing: Zipkin
- RabbitMQ: Fire-and-forget & RPC
- MQTT
Test applications Micronaut-GraalVM

Iván López @ilopmar
- Security: JWT, Basic Auth, Cookie, Session
- Scheduled jobs
- Micronaut Data JDBC: H2, Postgresql, Oracle, MariaDB, MS SQL Server
- Micronaut Data JPA-Hibernate: H2, Postgresql, MariaDB
- Bean Introspection
- Servlet: Tomcat & Jetty
- Flyway & Liquibase
- AWS app & function
- gRPC
Test applications Micronaut-GraalVM

Iván López @ilopmar
Gitlab CI

Iván López @ilopmar
Gitlab CI

Iván López @ilopmar
Gitlab CI 2 years ago

Iván López @ilopmar
x8
- JDK 8 & 11
- 2.3.x & 2.2.x
- GraalVM dev/stable
Gitlab CI today

Iván López @ilopmar
Gitlab CI

Iván López @ilopmar
Use cases

Iván López @ilopmar
- https://launch.micronaut.io (Google Cloud)
- Micronaut CLI: Linux, MacOS, Windows
- AWS Lambda + Custom runtime
Use cases

Iván López @ilopmar
GraalVM is a new and
interesting technology
Micronaut AoT is the
perfect match
Out-of-the-box support
in Micronaut
New improvements in
every release
Fast startup & low
memory footprint
Developers happy and
productive
Summary

Thank you!
@ilopmar
lopez.ivan@gmail.com
https://github.com/ilopmar
Iván López
https://bit.ly/jlove-micronaut
Questions?