General advice on speeding up first invocation timing.

[debrutal]

Hi everyone,

we are having a few services using Micronaut.

Environment
Our deployed setup relies on Google Cloud run, which simply put: is just a volatile container that is spawned when needed and shutdown if not used for a while.

There are a few aspects which slows down the first incoming request.

1. Artifact size (since Cloud Run is a dynamic infrastructure, artifacts needs to be download ad-hoc. The smaller the better)
2. Start of the JVM (whatever VM we are using in the container)
3. Bootstrapping of micronaut itself
4. Creation of dynamic objects/beans at runtime

I cannot say specifically the timings of each step, but comparing to different implementations with javascript and golang, 1 is low in impact.
3 has the most impact, which is mitigable by the platform itself using "warm" instances or permanent cpu allocation.
Still 4 has impact of around 1-1.5s

We have figured out that some dependencies, like micronauts declarative http-client is using (probably dynamic proxies) creating objects at runtime, which slows down our first request.

Knowing these two conditions, there are a few options in mind:
a. Mitigate 3 by having warm instances and creating all known objects at startup time e.g. using StartupEvent and trigger an http request, which instanciates all needed objects of the http-client
b. using native-image
c. using micronaut-aot

native-approach
While the documentations of micronaut and graalvm is working in all tutorials, having actual code using dependencies leads to errors in compilation.

As far as i have understood, micronauts framework itself is supporting native images pretty well since it avoids stuff like reflections. The issues comes with depending libraries.

Since this question also could be set on each dependent project or graalvm itself, i am seeking for general advices on understanding the actual error messages.

As followed the dependencies and our current error message running mvn package -Dpackaging=docker-native

Maven pom.xml

<dependencies>
		<dependency>
			<groupId>io.micronaut</groupId>
			<artifactId>micronaut-inject</artifactId>
			<scope>compile</scope>
		</dependency>
		<dependency>
			<groupId>io.micronaut</groupId>
			<artifactId>micronaut-http-client</artifactId>
			<scope>compile</scope>
		</dependency>
		<dependency>
			<groupId>io.micronaut</groupId>
			<artifactId>micronaut-http-server-netty</artifactId>
			<scope>compile</scope>
		</dependency>
		<!-- GCP -->
		<!-- https://micronaut-projects.github.io/micronaut-gcp/4.0.0/guide/ -->
		<dependency>
			<groupId>io.micronaut.gcp</groupId>
			<artifactId>micronaut-gcp-common</artifactId>
		</dependency>
		<dependency>
			<groupId>io.micronaut.gcp</groupId>
			<artifactId>micronaut-gcp-logging</artifactId>
		</dependency>
		<!-- tracing via opentelemetry-->
		<dependency>
			<groupId>io.micronaut.tracing</groupId>
			<artifactId>micronaut-tracing-opentelemetry-http</artifactId>
			<scope>compile</scope>
		</dependency>
		<!-- exporter for GCP -->
		<dependency>
			<groupId>com.google.cloud.opentelemetry</groupId>
			<artifactId>exporter-auto</artifactId>
			<scope>compile</scope>
		</dependency>
		<!-- log output "dummy" exporter -->
		<dependency>
			<groupId>io.opentelemetry</groupId>
			<artifactId>opentelemetry-exporter-logging</artifactId>
			<scope>compile</scope>
		</dependency>
		<!-- exporter for local testing -->
		<dependency>
			<groupId>io.opentelemetry</groupId>
			<artifactId>opentelemetry-exporter-zipkin</artifactId>
			<scope>compile</scope>
		</dependency>
		<!-- contains the in-memory exporter for unit tests -->
		<dependency>
			<groupId>io.opentelemetry</groupId>
			<artifactId>opentelemetry-sdk-testing</artifactId>
			<scope>test</scope>
		</dependency>
		<dependency>
			<groupId>io.micronaut.redis</groupId>
			<artifactId>micronaut-redis-lettuce</artifactId>
		</dependency>
		<dependency>
			<groupId>io.micronaut.problem</groupId>
			<artifactId>micronaut-problem-json</artifactId>
			<scope>compile</scope>
		</dependency>
		<!-- Test -->
		<dependency>
			<groupId>io.micronaut.test</groupId>
			<artifactId>micronaut-test-junit5</artifactId>
			<scope>test</scope>
		</dependency>
		<dependency>
			<groupId>org.junit.jupiter</groupId>
			<artifactId>junit-jupiter-engine</artifactId>
			<scope>test</scope>
		</dependency>
		<dependency>
			<groupId>org.junit.jupiter</groupId>
			<artifactId>junit-jupiter-params</artifactId>
			<scope>test</scope>
		</dependency>
		<dependency>
			<groupId>org.mockito</groupId>
			<artifactId>mockito-junit-jupiter</artifactId>
			<scope>test</scope>
		</dependency>
		<dependency>
			<groupId>com.github.tomakehurst</groupId>
			<artifactId>wiremock-jre8</artifactId>
			<version>2.33.2</version>
			<scope>test</scope>
		</dependency>
		<!-- https://micronaut-projects.github.io/micronaut-serialization/1.0.0/guide/ -->
		<dependency>
			<groupId>io.micronaut.serde</groupId>
			<artifactId>micronaut-serde-jackson</artifactId>
			<scope>compile</scope>
		</dependency>
		<dependency>
			<groupId>io.micronaut</groupId>
			<artifactId>micronaut-runtime</artifactId>
			<!-- Since we are using micronaut-serde we don't want to use jackson here, however micronaut's DefaultHttpClient still has some places where the JacksonDatabindMapper is hardcoded -->
			<!-- Until this is fixed we have to include the dependency again... -->
			<!--			<exclusions>-->
			<!--				<exclusion>-->
			<!--					<groupId>io.micronaut</groupId>-->
			<!--					<artifactId>micronaut-jackson-databind</artifactId>-->
			<!--				</exclusion>-->
			<!--			</exclusions>-->
			<scope>compile</scope>
		</dependency>
		<dependency>
			<groupId>io.micronaut.security</groupId>
			<artifactId>micronaut-security-oauth2</artifactId>
			<scope>compile</scope>
		</dependency>
		<dependency>
			<groupId>io.micronaut.security</groupId>
			<artifactId>micronaut-security-jwt</artifactId>
			<scope>compile</scope>
		</dependency>
		<!-- https://mvnrepository.com/artifact/com.nimbusds/nimbus-jose-jwt -->
		<dependency>
			<groupId>com.nimbusds</groupId>
			<artifactId>nimbus-jose-jwt</artifactId>
			<version>9.23</version>
		</dependency>
		<dependency>
			<groupId>ch.qos.logback</groupId>
			<artifactId>logback-classic</artifactId>
		</dependency>
		<!-- https://projectlombok.org/features/all -->
		<dependency>
			<groupId>org.projectlombok</groupId>
			<artifactId>lombok</artifactId>
			<scope>provided</scope>
		</dependency>
		<dependency>
			<groupId>io.micronaut.cache</groupId>
			<artifactId>micronaut-cache-noop</artifactId>
			<scope>test</scope>
		</dependency>
		<dependency>
			<groupId>io.swagger.core.v3</groupId>
			<artifactId>swagger-annotations</artifactId>
			<scope>provided</scope>
		</dependency>
		<dependency>
			<groupId>org.testcontainers</groupId>
			<artifactId>testcontainers</artifactId>
			<scope>test</scope>
		</dependency>
		<dependency>
			<groupId>org.testcontainers</groupId>
			<artifactId>junit-jupiter</artifactId>
			<scope>test</scope>
		</dependency>
	</dependencies>
	<build>
		<extensions>
			<extension>
				<groupId>com.google.cloud.artifactregistry</groupId>
				<artifactId>artifactregistry-maven-wagon</artifactId>
				<version>2.1.4</version>
			</extension>
		</extensions>
		<plugins>
			<plugin>
				<groupId>io.micronaut.build</groupId>
				<artifactId>micronaut-maven-plugin</artifactId>
			</plugin>

			<plugin>
				<groupId>com.google.cloud.tools</groupId>
				<artifactId>jib-maven-plugin</artifactId>
			</plugin>

			<plugin>
				<groupId>org.apache.maven.plugins</groupId>
				<artifactId>maven-compiler-plugin</artifactId>
				<configuration>
					<!-- Uncomment to enable incremental compilation -->
					<useIncrementalCompilation>false</useIncrementalCompilation>
					<annotationProcessorPaths combine.self="override">
						<path>
							<groupId>org.projectlombok</groupId>
							<artifactId>lombok</artifactId>
							<version>${lombok.version}</version>
						</path>
						<path>
							<groupId>io.micronaut</groupId>
							<artifactId>micronaut-graal</artifactId>
							<version>${micronaut.version}</version>
						</path>
						<path>
							<groupId>io.micronaut</groupId>
							<artifactId>micronaut-http-validation</artifactId>
							<version>${micronaut.version}</version>
						</path>
						<path>
							<groupId>io.micronaut</groupId>
							<artifactId>micronaut-inject-java</artifactId>
							<version>${micronaut.version}</version>
						</path>
						<path>
							<groupId>io.micronaut</groupId>
							<artifactId>micronaut-validation</artifactId>
							<version>${micronaut.version}</version>
						</path>
						<path>
							<groupId>io.micronaut.serde</groupId>
							<artifactId>micronaut-serde-processor</artifactId>
							<version>${micronaut.serialization.version}</version>
						</path>
						<path>
							<groupId>io.micronaut.openapi</groupId>
							<artifactId>micronaut-openapi</artifactId>
							<version>${micronaut.openapi.version}</version>
						</path>
					</annotationProcessorPaths>
					<compilerArgs>
						<arg>-Amicronaut.processing.group=de.project.sample</arg>
						<arg>-Amicronaut.processing.module=sample</arg>
					</compilerArgs>
				</configuration>
			</plugin>
			<plugin>
				<groupId>org.jacoco</groupId>
				<artifactId>jacoco-maven-plugin</artifactId>
				<version>0.8.8</version>
				<executions>
					<execution>
						<goals>
							<goal>prepare-agent</goal>
						</goals>
					</execution>
					<execution>
						<id>generate-code-coverage-report</id>
						<phase>test</phase>
						<goals>
							<goal>report</goal>
						</goals>
					</execution>
				</executions>
			</plugin>
		</plugins>
	</build>

mvn package -Dpackaging=docker-native

[INFO] Scanning for projects...
[WARNING]
[WARNING] Some problems were encountered while building the effective model for de.project.sample:sample:docker-native:SNAPSHOT
[WARNING] 'version' uses an unsupported snapshot version format, should be '*-SNAPSHOT' instead. @ line 7, column 11
[WARNING]
[WARNING] It is highly recommended to fix these problems because they threaten the stability of your build.
[WARNING]
[WARNING] For this reason, future Maven versions might no longer support building such malformed projects.
[WARNING]
[INFO]
[INFO] -------------------< de.project.sample:sample >-------------------
[INFO] Building sample SNAPSHOT
[INFO] ---------------------------[ docker-native ]----------------------------
[INFO]
[INFO] --- jacoco-maven-plugin:0.8.8:prepare-agent (default) @ sample ---
[INFO] argLine set to -javaagent:/home/dwinter/.m2/repository/org/jacoco/org.jacoco.agent/0.8.8/org.jacoco.agent-0.8.8-runtime.jar=destfile=/mnt/c/Users/WinterDen/dev/projects/sample/sample/target/jacoco.exec
[INFO]
[INFO] --- maven-resources-plugin:3.2.0:resources (default-resources) @ sample ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Using 'UTF-8' encoding to copy filtered properties files.
[INFO] Copying 6 resources
[INFO]
[INFO] --- maven-compiler-plugin:3.10.1:compile (default-compile) @ sample ---
[INFO] Nothing to compile - all classes are up to date
[INFO]
[INFO] --- jacoco-maven-plugin:0.8.8:report (generate-code-coverage-report) @sample ---
[INFO] Skipping JaCoCo execution due to missing execution data file.
[INFO]
[INFO] --- micronaut-maven-plugin:3.4.0:aot-analysis (default-aot-analysis) @ sample ---
[INFO]
[INFO] --- micronaut-maven-plugin:3.4.0:graalvm-resources (default-graalvm-resources) @ sample ---
[INFO] Generating /mnt/c/Users/WinterDen/dev/projects/sahmple/sample/target/classes/META-INF/native-image/de.project.sample/sample/resource-config.json
[INFO]
[INFO] --- micronaut-maven-plugin:3.4.0:docker-native (default-docker-native) @ sample ---
[INFO] Exposing port: 8080
[INFO] Using BASE_IMAGE: ghcr.io/graalvm/native-image:ol7-java17-22.2.0
[INFO] Using BASE_IMAGE_RUN: frolvlad/alpine-glibc:alpine-3.12
[INFO] Using CLASS_NAME: de.project.sample.Application
[INFO] Step 1/17 : ARG BASE_IMAGE
[INFO]
[INFO] Step 2/17 : ARG BASE_IMAGE_RUN
[INFO]
[INFO] Step 3/17 : FROM ${BASE_IMAGE} AS builder
[INFO]
[INFO]  ---> 4efdfc1bf541
[INFO] Step 4/17 : WORKDIR /home/app
[INFO]
[INFO]  ---> Using cache
[INFO]  ---> 44477f9eaea6
[INFO] Step 5/17 : COPY classes /home/app/classes
[INFO]
[INFO]  ---> Using cache
[INFO]  ---> eacea005c745
[INFO] Step 6/17 : COPY dependency/* /home/app/libs/
[INFO]
[INFO]  ---> Using cache
[INFO]  ---> 0f9ad635bfdd
[INFO] Step 7/17 : ARG CLASS_NAME
[INFO]
[INFO]  ---> Using cache
[INFO]  ---> f6ca3f57e0fe
[INFO] Step 8/17 : ARG GRAALVM_ARGS=""
[INFO]
[INFO]  ---> Using cache
[INFO]  ---> 6741f7b6dd7b
[INFO] Step 9/17 : ENV USE_NATIVE_IMAGE_JAVA_PLATFORM_MODULE_SYSTEM=false
[INFO]
[INFO]  ---> Using cache
[INFO]  ---> c69057348f61
[INFO] Step 10/17 : RUN native-image ${GRAALVM_ARGS} -H:Class=${CLASS_NAME} -H:Name=application --no-fallback -cp "/home/app/libs/*:/home/app/classes/"
[INFO]
[INFO]  ---> Running in 07fb304e0c71
[INFO] Warning: Using a deprecated option --allow-incomplete-classpath from 'META-INF/native-image/com.google.api/gax/native-image.properties' in 'file:///home/app/libs/gax-2.19.1.jar'. Allowing an incomplete classpath is now the default. Use --link-at-build-time to report linking errors at image build time for a class or package.

[INFO] Warning: Using a deprecated option --allow-incomplete-classpath from 'META-INF/native-image/io.micronaut/micronaut-inject/native-image.properties' in 'file:///home/app/libs/micronaut-inject-3.7.1.jar'. Allowing an incomplete classpath is now the default. Use --link-at-build-time to report linking errors at image build time for a class or package.

[INFO] ========================================================================================================================
GraalVM Native Image
[INFO] : Generating '
[INFO] application' (
[INFO] executable)...
========================================================================================================================
[INFO] Warning: Could not resolve io.opentelemetry.exporter.jaeger.JaegerGrpcSpanExporter for reflection configuration. Reason: java.lang.ClassNotFoundException: io.opentelemetry.exporter.jaeger.JaegerGrpcSpanExporter.

[INFO] Warning: Could not resolve io.opentelemetry.exporter.otlp.trace.OtlpGrpcSpanExporter for reflection configuration. Reason: java.lang.ClassNotFoundException: io.opentelemetry.exporter.otlp.trace.OtlpGrpcSpanExporter.

[INFO] [1/7] Initializing...                                                                                   (12.2s @ 0.61GB)
[INFO]  Version info: 'GraalVM 22.2.0 Java 17 CE'

[INFO] Java version info: '
[INFO] 17.0.4+8-jvmci-22.2-b06'
[INFO]
[INFO] C compiler
[INFO] :
[INFO] gcc (redhat, x86_64, 4.8.5)

[INFO] Garbage collector:
[INFO] Serial GC
[INFO]  7 user-specific feature(s)
[INFO]
[INFO]  - com.google.api.gax.nativeimage.GoogleJsonClientFeature
 -
[INFO] com.google.api.gax.nativeimage.OpenCensusFeature
[INFO]
 - com.oracle.svm.thirdparty.gson.GsonFeature
 - io.micronaut.buffer.netty.NettyFeature
[INFO]
 -
[INFO] io.micronaut.core.graal.ServiceLoaderFeature
[INFO]  - io.micronaut.http.netty.graal.HttpNettyFeature
 - io.micronaut.jackson.JacksonDatabindFeature
[INFO] To see how the classes got initialized, use --trace-class-initialization=io.grpc.netty.shaded.io.netty.buffer.ByteBufAllocator,io.grpc.netty.shaded.io.netty.buffer.UnpooledUnsafeDirectByteBuf,io.grpc.netty.shaded.io.netty.handler.ssl.PemValue,io.grpc.netty.shaded.io.netty.buffer.UnpooledDirectByteBuf,io.grpc.netty.shaded.io.netty.buffer.PooledSlicedByteBuf,io.grpc.netty.shaded.io.netty.util.AbstractReferenceCounted,io.grpc.netty.shaded.io.netty.handler.ssl.PemPrivateKey,io.grpc.netty.shaded.io.netty.buffer.AbstractReferenceCountedByteBuf,io.grpc.netty.shaded.io.netty.buffer.PooledByteBuf,io.grpc.netty.shaded.io.netty.buffer.ByteBufUtil,io.grpc.netty.shaded.io.netty.buffer.UnpooledHeapByteBuf,io.grpc.netty.shaded.io.netty.buffer.PooledUnsafeDirectByteBuf,io.grpc.netty.shaded.io.netty.buffer.UnpooledByteBufAllocator$InstrumentedUnpooledUnsafeDirectByteBuf,io.grpc.netty.shaded.io.netty.buffer.PooledByteBufAllocator,io.grpc.netty.shaded.io.netty.buffer.AbstractPooledDerivedByteBuf
[INFO] [2/7] Performing analysis...  [***]                                                                     (48.4s @ 3.11GB)
[INFO]   22,423 (94.10%) of 23,828 classes reachable
[INFO]   36,038 (61.99%) of 58,137 fields reachable
[INFO]  111,195 (65.68%) of 169,301 methods reachable
[INFO]    1,274 classes,   558 fields, and 7,294 methods registered for reflection
[INFO]
[INFO] Error: Classes that should be initialized at run time got initialized during image building:
 io.grpc.netty.shaded.io.netty.buffer.ByteBufAllocator the class was requested to be initialized at run time (from 'META-INF/native-image/io.netty/buffer/native-image.properties' in 'file:///home/app/libs/exporter-auto-0.22.0-alpha.jar' with 'io.grpc.netty.shaded.io.netty.buffer.ByteBufAllocator'). To see why io.grpc.netty.shaded.io.netty.buffer.ByteBufAllocator got initialized use --trace-class-initialization=io.grpc.netty.shaded.io.netty.buffer.ByteBufAllocator
io.grpc.netty.shaded.io.netty.buffer.UnpooledUnsafeDirectByteBuf the class was requested to be initialized at run time (subtype of io.grpc.netty.shaded.io.netty.buffer.AbstractReferenceCountedByteBuf). To see why io.grpc.netty.shaded.io.netty.buffer.UnpooledUnsafeDirectByteBuf got initialized use --trace-class-initialization=io.grpc.netty.shaded.io.netty.buffer.UnpooledUnsafeDirectByteBuf
io.grpc.netty.shaded.io.netty.handler.ssl.PemValue the class was requested to be initialized at run time (subtype of io.grpc.netty.shaded.io.netty.util.AbstractReferenceCounted). To see why io.grpc.netty.shaded.io.netty.handler.ssl.PemValue got initialized use --trace-class-initialization=io.grpc.netty.shaded.io.netty.handler.ssl.PemValue
io.grpc.netty.shaded.io.netty.buffer.UnpooledDirectByteBuf the class was requested to be initialized at run time (subtype of io.grpc.netty.shaded.io.netty.buffer.AbstractReferenceCountedByteBuf). To see why io.grpc.netty.shaded.io.netty.buffer.UnpooledDirectByteBuf got initialized use --trace-class-initialization=io.grpc.netty.shaded.io.netty.buffer.UnpooledDirectByteBuf
io.grpc.netty.shaded.io.netty.buffer.PooledSlicedByteBuf the class was requested to be initialized at run time (subtype of io.grpc.netty.shaded.io.netty.buffer.AbstractReferenceCountedByteBuf). To see why io.grpc.netty.shaded.io.netty.buffer.PooledSlicedByteBuf got initialized use --trace-class-initialization=io.grpc.netty.shaded.io.netty.buffer.PooledSlicedByteBuf
io.grpc.netty.shaded.io.netty.util.AbstractReferenceCounted the class was requested to be initialized at run time (from 'META-INF/native-image/io.netty/common/native-image.properties' in 'file:///home/app/libs/exporter-auto-0.22.0-alpha.jar' with 'io.grpc.netty.shaded.io.netty.util.AbstractReferenceCounted'). To see why io.grpc.netty.shaded.io.netty.util.AbstractReferenceCounted got initialized use --trace-class-initialization=io.grpc.netty.shaded.io.netty.util.AbstractReferenceCounted
io.grpc.netty.shaded.io.netty.handler.ssl.PemPrivateKey the class was requested to be initialized at run time (subtype of io.grpc.netty.shaded.io.netty.util.AbstractReferenceCounted). To see why io.grpc.netty.shaded.io.netty.handler.ssl.PemPrivateKey got initialized use --trace-class-initialization=io.grpc.netty.shaded.io.netty.handler.ssl.PemPrivateKey
io.grpc.netty.shaded.io.netty.buffer.AbstractReferenceCountedByteBuf the class was requested to be initialized at run time (from 'META-INF/native-image/io.netty/buffer/native-image.properties' in 'file:///home/app/libs/exporter-auto-0.22.0-alpha.jar' with 'io.grpc.netty.shaded.io.netty.buffer.AbstractReferenceCountedByteBuf'). To see why io.grpc.netty.shaded.io.netty.buffer.AbstractReferenceCountedByteBuf got initialized use --trace-class-initialization=io.grpc.netty.shaded.io.netty.buffer.AbstractReferenceCountedByteBuf
io.grpc.netty.shaded.io.netty.buffer.PooledByteBuf the class was requested to be initialized at run time (subtype of io.grpc.netty.shaded.io.netty.buffer.AbstractReferenceCountedByteBuf). To see why io.grpc.netty.shaded.io.netty.buffer.PooledByteBuf got initialized use --trace-class-initialization=io.grpc.netty.shaded.io.netty.buffer.PooledByteBuf
io.grpc.netty.shaded.io.netty.buffer.ByteBufUtil the class was requested to be initialized at run time (from 'META-INF/native-image/io.netty/buffer/native-image.properties' in 'file:///home/app/libs/exporter-auto-0.22.0-alpha.jar' with 'io.grpc.netty.shaded.io.netty.buffer.ByteBufUtil'). To see why io.grpc.netty.shaded.io.netty.buffer.ByteBufUtil got initialized use --trace-class-initialization=io.grpc.netty.shaded.io.netty.buffer.ByteBufUtil
io.grpc.netty.shaded.io.netty.buffer.UnpooledHeapByteBuf the class was requested to be initialized at run time (subtype of io.grpc.netty.shaded.io.netty.buffer.AbstractReferenceCountedByteBuf). To see why io.grpc.netty.shaded.io.netty.buffer.UnpooledHeapByteBuf got initialized use --trace-class-initialization=io.grpc.netty.shaded.io.netty.buffer.UnpooledHeapByteBuf
io.grpc.netty.shaded.io.netty.buffer.PooledUnsafeDirectByteBuf the class was requested to be initialized at run time (subtype of io.grpc.netty.shaded.io.netty.buffer.AbstractReferenceCountedByteBuf). To see why io.grpc.netty.shaded.io.netty.buffer.PooledUnsafeDirectByteBuf got initialized use --trace-class-initialization=io.grpc.netty.shaded.io.netty.buffer.PooledUnsafeDirectByteBuf
io.grpc.netty.shaded.io.netty.buffer.UnpooledByteBufAllocator$InstrumentedUnpooledUnsafeDirectByteBuf the class was requested to be initialized at run time (subtype of io.grpc.netty.shaded.io.netty.buffer.AbstractReferenceCountedByteBuf). To see why io.grpc.netty.shaded.io.netty.buffer.UnpooledByteBufAllocator$InstrumentedUnpooledUnsafeDirectByteBuf got initialized use --trace-class-initialization=io.grpc.netty.shaded.io.netty.buffer.UnpooledByteBufAllocator$InstrumentedUnpooledUnsafeDirectByteBuf
io.grpc.netty.shaded.io.netty.buffer.PooledByteBufAllocator the class was requested to be initialized at run time (from 'META-INF/native-image/io.netty/buffer/native-image.properties' in 'file:///home/app/libs/exporter-auto-0.22.0-alpha.jar' with 'io.grpc.netty.shaded.io.netty.buffer.PooledByteBufAllocator'). To see why io.grpc.netty.shaded.io.netty.buffer.PooledByteBufAllocator got initialized use --trace-class-initialization=io.grpc.netty.shaded.io.netty.buffer.PooledByteBufAllocator
io.grpc.netty.shaded.io.netty.buffer.AbstractPooledDerivedByteBuf the class was requested to be initialized at run time (subtype of io.grpc.netty.shaded.io.netty.buffer.AbstractReferenceCountedByteBuf). To see why io.grpc.netty.shaded.io.netty.buffer.AbstractPooledDerivedByteBuf got initialized use --trace-class-initialization=io.grpc.netty.shaded.io.netty.buffer.AbstractPooledDerivedByteBuf


[INFO] Error: Use -H:+ReportExceptionStackTraces to print stacktrace of underlying exception

[INFO] ------------------------------------------------------------------------------------------------------------------------
[INFO]                         4.0s (6.4% of total time) in 26 GCs | Peak RSS: 6.64GB | CPU load: 7.13
[INFO]
========================================================================================================================
[INFO]
[INFO] Failed generating 'application' after
[INFO]  1m 1s.
[INFO] Error: Image build request failed with exit status 1

[ERROR] The command '/bin/sh -c native-image ${GRAALVM_ARGS} -H:Class=${CLASS_NAME} -H:Name=application --no-fallback -cp "/home/app/libs/*:/home/app/classes/"' returned a non-zero code: 1
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  01:38 min
[INFO] Finished at: 2022-10-20T08:32:49+02:00
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal io.micronaut.build:micronaut-maven-plugin:3.4.0:docker-native (default-docker-native) on project sample: Execution default-docker-native of goal io.micronaut.build:micronaut-maven-plugin:3.4.0:docker-native failed: Could not build image: The command '/bin/sh -c native-image ${GRAALVM_ARGS} -H:Class=${CLASS_NAME} -H:Name=application --no-fallback -cp "/home/app/libs/*:/home/app/classes/"' returned a non-zero code: 1 -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:

AOT
I still don't understand the actual use of it. Is this a feasible way? I could not find comprehensive documentation on this.

[graemerocher]

Looks like you are using gRPC correct? Do you have an narrowed down example that causes the native image build error?

[debrutal]

I am not using gRPC explicitly, though it might be, that google internaly uses it to communicate into its own services.
For now i don't have a more specific or shareable example to simulate this.
I will have to split the application into its features and narrow down which part is actually causing the trouble.

[shingjo]

The issue is with GraalVM and GCP modules. They need an extra information, see https://micronaut-projects.github.io/micronaut-gcp/latest/guide/#nativeImage.

However, just tested it out with mvn package -Dpackaging=docker-native and the above link documentation doesn't work. To fix the issue add

<profiles>
        <profile>
            <id>graalVM</id>
            <activation>
                <property>
                    <name>packaging</name>
                    <value>native-image</value>
                </property>
            </activation>
            <dependencies>
                <dependency>
                    <groupId>com.google.cloud</groupId>
                    <artifactId>native-image-support</artifactId>
               </dependency>
            </dependencies>
        </profile>
        <profile>
            <id>graalVM-docker</id>
            <activation>
                <property>
                    <name>packaging</name>
                    <value>docker-native</value>
                </property>
            </activation>
            <dependencies>
                <dependency>
                    <groupId>com.google.cloud</groupId>
                    <artifactId>native-image-support</artifactId>
               </dependency>
            </dependencies>
        </profile>
    </profiles>

to your pom.xml. And that should allow you to create a native docker image.

[debrutal]

Hey shingjo, thanks for that impulse, i read that is was not necessary since a specific version of the bom, but this brought me a step closer.

1. Setup
   a. Using the profiles as mentioned mvn packaging -PgraalVM,graalVM-docker succeed to the next issue, which is related to Caching as @graemerocher already mentioned .
   Though it does not produce the actual native image as it's last step is the java shade plugin and then exits after around 1m. Am i missing something?
   While adding the dependency within the general project, using mvn package -Dpackaging=native-image does actually succeed generating the native-image withing ~5min
   Since we test our cache hits, this explicit test fails as expected due to the mentioned issue.

2. Executing the native image also indicates that Properties are still loaded via reflections and then fails on execution. But maybe this is just a symptom of its pre issues.

@Property(name = "some.value.from.properties", defaultValue = "72h")
    private Duration duration;

Caused by: java.lang.NoSuchFieldError: No field 'duration' found for type: de.project.sample
        at io.micronaut.core.reflect.ReflectionUtils.lambda$getRequiredField$2(ReflectionUtils.java:294)
        at java.util.Optional.orElseThrow(Optional.java:403)
        at io.micronaut.core.reflect.ReflectionUtils.getRequiredField(ReflectionUtils.java:294)
        at io.micronaut.context.AbstractInitializableBeanDefinition.setFieldWithReflection(AbstractInitializableBeanDefinition.java:979)
        ... 17 common frames omitted

3. Type Hints
   I am not aware how to use TypeHints and what to do with it. I assume it is used to provide hints on the Limitations by the graalvm to support libraries how to handle the limitation. Is this correct?
   I could not find any good documentation for this, do you have any hints on this (no pun intended ;) )
   Are there any experiences using tools like graalvm-hints-processor?

[shingjo]

In regards to number 2, change from private to protected. Private would require reflection and we recommend not using private for field injection even in non-Native Micronaut applications to avoid reflection.

[debrutal]

That's a nice hint! I did not think about visibility as a limitation for the framework to access the field. I will definitely change that.

[graemerocher]

alternative is to add @ReflectiveAccess to the private field

[graemerocher]

for Caffeine you can do something similar to micronaut-projects/micronaut-cache#280 (comment)