试用Spring Native Beta版

sofia 3年前 (2021-07-05) Serverless | 抢沙发 984

文章评分 2 次，平均分 3.0 ：

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环境
准备工作
用samples/data-jpa实验
通过Spring Initializa创建项目

环境

Debian 10.8 (WSL2)
Docker 社区版（客户端=19.03.11，服务器=20.10.5）
GraalVM CE 21.0.0.2（构建 11.0.10+8-jvmci-21.0-b06）
Apache Maven 3.6.3

准备工作

使用gs-rest-service（https://github.com/spring-guides/gs-rest-service）。它是spring-boot-starter-web的样品项目，不包含任何关于native image的提示和资源。

在pom.xml中添加Spring Native的构建。中途会发出警告信息（Could not register reflection metadata for…），但是成功了。

$ git clone https://github.com/spring-guides/gs-rest-service
$ cd gs-rest-service/complete
$ mvn spring-boot:build-image
<snip>
<snip>
<snip>
[INFO] --- spring-boot-maven-plugin:2.4.3:build-image (default-cli) @ rest-service ---
[INFO] Building image 'com.example/rest-service:0.0.1-SNAPSHOT'
[INFO]
[INFO]  > Pulling builder image 'docker.io/paketobuildpacks/builder:tiny' 100%
[INFO]  > Pulled builder image 'paketobuildpacks/builder@sha256:870c2769a65f29c62a0ffe397ae14cc1d61c2e90ebe85f068e8e2fff775c0344'
[INFO]  > Pulling run image 'docker.io/paketobuildpacks/run:tiny-cnb' 100%
[INFO]  > Pulled run image 'paketobuildpacks/run@sha256:30e7b4b0e1de31e763c7b631161a508c0ef710ea44924f65177afad2644312b9'
[INFO]  > Executing lifecycle version v0.10.2
[INFO]  > Using build cache volume 'pack-cache-64d3936a0bf9.build'
[INFO]
[INFO]  > Running creator
[INFO]     [creator]     ===> DETECTING
[INFO]     [creator]     4 of 11 buildpacks participating
[INFO]     [creator]     paketo-buildpacks/graalvm        6.0.0
[INFO]     [creator]     paketo-buildpacks/executable-jar 5.0.0
[INFO]     [creator]     paketo-buildpacks/spring-boot    4.1.0
[INFO]     [creator]     paketo-buildpacks/native-image   4.0.0
[INFO]     [creator]     ===> ANALYZING
[INFO]     [creator]     Previous image with name "com.example/rest-service:0.0.1-SNAPSHOT" not found
[INFO]     [creator]     ===> RESTORING
[INFO]     [creator]     ===> BUILDING
[INFO]     [creator]
[INFO]     [creator]     Paketo GraalVM Buildpack 6.0.0
[INFO]     [creator]       https://github.com/paketo-buildpacks/graalvm
[INFO]     [creator]       Build Configuration:
[INFO]     [creator]         $BP_JVM_VERSION              8.*             the Java version
[INFO]     [creator]       Launch Configuration:
[INFO]     [creator]         $BPL_JVM_HEAD_ROOM           0               the headroom in memory calculation
[INFO]     [creator]         $BPL_JVM_LOADED_CLASS_COUNT  35% of classes  the number of loaded classes in memory calculation
[INFO]     [creator]         $BPL_JVM_THREAD_COUNT        250             the number of threads in memory calculation
[INFO]     [creator]         $JAVA_TOOL_OPTIONS                           the JVM launch flags
[INFO]     [creator]       GraalVM JDK 8.0.282: Contributing to layer
[INFO]     [creator]         Downloading from https://github.com/graalvm/graalvm-ce-builds/releases/download/vm-21.0.0.2/graalvm-ce-java8-linux-amd64-21.0.0.2.tar.gz
[INFO]     [creator]         Verifying checksum
[INFO]     [creator]         Expanding to /layers/paketo-buildpacks_graalvm/jdk
[INFO]     [creator]         Adding 129 container CA certificates to JVM truststore
[INFO]     [creator]       GraalVM Native Image Substrate VM 8.0.282
[INFO]     [creator]         Downloading from https://github.com/graalvm/graalvm-ce-builds/releases/download/vm-21.0.0.2/native-image-installable-svm-java8-linux-amd64-21.0.0.2.jar
[INFO]     [creator]         Verifying checksum
[INFO]     [creator]         Installing substrate VM
[INFO]     [creator]     Processing Component archive: /tmp/e2a182c1f79d8a97b537b843eb65e15ef5ebdd088ad01acd606bf26b1846612e/native-image-installable-svm-java8-linux-amd64-21.0.0.2.jar
[INFO]     [creator]     Installing new component: Native Image (org.graalvm.native-image, version 21.0.0.2)
[INFO]     [creator]         Writing env.build/JAVA_HOME.override
[INFO]     [creator]         Writing env.build/JDK_HOME.override
[INFO]     [creator]
[INFO]     [creator]     Paketo Executable JAR Buildpack 5.0.0
[INFO]     [creator]       https://github.com/paketo-buildpacks/executable-jar
[INFO]     [creator]       Class Path: Contributing to layer
[INFO]     [creator]         Writing env.build/CLASSPATH.delim
[INFO]     [creator]         Writing env.build/CLASSPATH.prepend
[INFO]     [creator]
[INFO]     [creator]     Paketo Spring Boot Buildpack 4.1.0
[INFO]     [creator]       https://github.com/paketo-buildpacks/spring-boot
[INFO]     [creator]       Class Path: Contributing to layer
[INFO]     [creator]         Writing env.build/CLASSPATH.append
[INFO]     [creator]         Writing env.build/CLASSPATH.delim
[INFO]     [creator]       Image labels:
[INFO]     [creator]         org.opencontainers.image.title
[INFO]     [creator]         org.opencontainers.image.version
[INFO]     [creator]         org.springframework.boot.spring-configuration-metadata.json
[INFO]     [creator]         org.springframework.boot.version
[INFO]     [creator]
[INFO]     [creator]     Paketo Native Image Buildpack 4.0.0
[INFO]     [creator]       https://github.com/paketo-buildpacks/native-image
[INFO]     [creator]       Build Configuration:
[INFO]     [creator]         $BP_NATIVE_IMAGE                  true  enable native image build
[INFO]     [creator]         $BP_NATIVE_IMAGE_BUILD_ARGUMENTS        arguments to pass to the native-image command
[INFO]     [creator]       Native Image: Contributing to layer
[INFO]     [creator]         GraalVM Version 21.0.0.2 (Java Version 1.8.0_282-b07)
[INFO]     [creator]         Executing native-image -H:+StaticExecutableWithDynamicLibC -H:Name=/layers/paketo-buildpacks_native-image/native-image/com.example.restservice.RestServiceApplication
<snip>
<snip>
<snip>
[INFO]     [creator]     ===> EXPORTING
[INFO]     [creator]     Adding 1/1 app layer(s)
[INFO]     [creator]     Adding layer 'launcher'
[INFO]     [creator]     Adding layer 'config'
[INFO]     [creator]     Adding layer 'process-types'
[INFO]     [creator]     Adding label 'io.buildpacks.lifecycle.metadata'
[INFO]     [creator]     Adding label 'io.buildpacks.build.metadata'
[INFO]     [creator]     Adding label 'io.buildpacks.project.metadata'
[INFO]     [creator]     Adding label 'org.opencontainers.image.title'
[INFO]     [creator]     Adding label 'org.opencontainers.image.version'
[INFO]     [creator]     Adding label 'org.springframework.boot.spring-configuration-metadata.json'
[INFO]     [creator]     Adding label 'org.springframework.boot.version'
[INFO]     [creator]     Setting default process type 'web'
[INFO]     [creator]     *** Images (dfa282b4df5d):
[INFO]     [creator]           com.example/rest-service:0.0.1-SNAPSHOT
[INFO]     [creator]     Adding cache layer 'paketo-buildpacks/graalvm:jdk'
[INFO]     [creator]     Adding cache layer 'paketo-buildpacks/native-image:native-image'
[INFO]
[INFO] Successfully built image 'com.example/rest-service:0.0.1-SNAPSHOT'

制作的镜像大小（75.3MB）。

$ docker images | grep com.example/rest-service
com.example/rest-service              0.0.1-SNAPSHOT      dfa282b4df5d        41 years ago        75.3MB

$ dive --ci com.example/rest-service:0.0.1-SNAPSHOT
  Using default CI config
Image Source: docker://com.example/rest-service:0.0.1-SNAPSHOT
Fetching image... (this can take a while for large images)
Analyzing image...
  efficiency: 99.9996 %
  wastedBytes: 481 bytes (481 B)
  userWastedPercent: 0.0008 %
Inefficient Files:
Count  Wasted Space  File Path
    2         342 B  /etc/passwd
    2         139 B  /etc/group
Results:
  PASS: highestUserWastedPercent
  SKIP: highestWastedBytes: rule disabled
  PASS: lowestEfficiency
Result:PASS [Total:3] [Passed:2] [Failed:0] [Warn:0] [Skipped:1]

当然启动时间非常短。Started RestServiceApplication in 0.065 seconds（JVM running for 0.067）真厉害啊。一般用JVM来执行的话需要10秒，所以会高速化100倍以上。

为什么每次接受请求都会初始化dispatcherServlet呢？

$ curl -s localhost:8080/greeting
{"id":1,"content":"Hello, World!"}
$ curl -s localhost:8080/greeting
{"id":2,"content":"Hello, World!"}

---
$ docker run --rm -i -p 8080:8080 com.example/rest-service:0.0.1-SNAPSHOT
2021-03-12 01:29:33.773  INFO 1 --- [           main] o.s.nativex.NativeListener               : This application is bootstrapped with code generated with Spring AOT

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::                (v2.4.3)

2021-03-12 01:29:33.774  INFO 1 --- [           main] c.e.restservice.RestServiceApplication   : Starting RestServiceApplication using Java 1.8.0_282 on b573482d1411 with PID 1 (/workspace/com.example.restservice.RestServiceApplication started by cnb in /workspace)
2021-03-12 01:29:33.774  INFO 1 --- [           main] c.e.restservice.RestServiceApplication   : No active profile set, falling back to default profiles: default
2021-03-12 01:29:33.805  INFO 1 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8080 (http)
Mar 12, 2021 1:29:33 AM org.apache.coyote.AbstractProtocol init
INFO: Initializing ProtocolHandler ["http-nio-8080"]
Mar 12, 2021 1:29:33 AM org.apache.catalina.core.StandardService startInternal
INFO: Starting service [Tomcat]
Mar 12, 2021 1:29:33 AM org.apache.catalina.core.StandardEngine startInternal
INFO: Starting Servlet engine: [Apache Tomcat/9.0.43]
Mar 12, 2021 1:29:33 AM org.apache.catalina.core.ApplicationContext log
INFO: Initializing Spring embedded WebApplicationContext
2021-03-12 01:29:33.807  INFO 1 --- [           main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 32 ms
2021-03-12 01:29:33.816  INFO 1 --- [           main] o.s.s.concurrent.ThreadPoolTaskExecutor  : Initializing ExecutorService 'applicationTaskExecutor'
Mar 12, 2021 1:29:33 AM org.apache.coyote.AbstractProtocol start
INFO: Starting ProtocolHandler ["http-nio-8080"]
2021-03-12 01:29:33.824  INFO 1 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8080 (http) with context path ''
2021-03-12 01:29:33.825  INFO 1 --- [           main] c.e.restservice.RestServiceApplication   : Started RestServiceApplication in 0.065 seconds (JVM running for 0.067)
Mar 12, 2021 1:31:09 AM org.apache.catalina.core.ApplicationContext log
INFO: Initializing Spring DispatcherServlet 'dispatcherServlet'
2021-03-12 01:31:09.977  INFO 1 --- [nio-8080-exec-2] o.s.web.servlet.DispatcherServlet        : Initializing Servlet 'dispatcherServlet'
2021-03-12 01:31:09.977  INFO 1 --- [nio-8080-exec-2] o.s.web.servlet.DispatcherServlet        : Completed initialization in 0 ms
Mar 12, 2021 1:31:09 AM org.apache.catalina.core.ApplicationContext log
INFO: Initializing Spring DispatcherServlet 'dispatcherServlet'
2021-03-12 01:31:09.977  INFO 1 --- [nio-8080-exec-2] o.s.web.servlet.DispatcherServlet        : Initializing Servlet 'dispatcherServlet'
2021-03-12 01:31:09.977  INFO 1 --- [nio-8080-exec-2] o.s.web.servlet.DispatcherServlet        : Completed initialization in 0 ms

用samples/data-jpa实验

$ git clone https://github.com/spring-projects-experimental/spring-native
$ cd spring-native/samples/data-jpa

build-image到中途为止都很顺利，但是失败了。

$ mvn spring-boot:build-image
<snip>
<snip>
<snip>
[INFO]     [creator]     WARNING: Could not register reflection metadata for org.springframework.data.querydsl.binding.QuerydslBindingsFactory. Reason: java.lang.NoClassDefFoundError: com/querydsl/core/types/EntityPath.
[INFO]     [creator]     WARNING: Could not register reflection metadata for org.springframework.transaction.ReactiveTransactionManager. Reason: java.lang.NoClassDefFoundError: reactor/core/publisher/Mono.
[INFO]     [creator]     WARNING: Could not register reflection metadata for org.springframework.boot.autoconfigure.transaction.jta.BitronixJtaConfiguration. Reason: java.lang.NoClassDefFoundError: bitronix/tm/Configuration.
[INFO]     [creator]     01:00:52.940 [ForkJoinPool-2-worker-1] DEBUG org.jboss.logging - Logging Provider: org.jboss.logging.Log4j2LoggerProvider
[INFO]     [creator]     Error: Image build request failed with exit status 137
[INFO]     [creator]     unable to invoke layer creator
[INFO]     [creator]     unable to contribute native-image layer
[INFO]     [creator]     error running build
[INFO]     [creator]     exit status 137
[INFO]     [creator]     ERROR: failed to build: exit status 1
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------

exit status的说明没有写在native image上。

根据Quarkus的Open Issue#1140的评论，OOOMkiller的异常结束。如果从native image开始实行的java的堆尺寸变大的话可能会解决。

Building a native image with graalvm ce rc11 & rc12, I occasionally see the following error;

Error: Image building with exit status 137

This occurs if the system runs out of ram (including free swap pages) and the OOM Killer terminates the native image build process. The error message seen by users is not very informative. Could we capture the exit code of the native-image process, and if equal to 137, display a more helpful message to users?

$ mvn spring-boot:build-image
<snip>
<snip>
<snip>
[INFO]     [creator]     WARNING: Could not register reflection metadata for org.springframework.data.querydsl.binding.QuerydslBindingsFactory. Reason: java.lang.NoClassDefFoundError: com/querydsl/core/types/EntityPath.
[INFO]     [creator]     WARNING: Could not register reflection metadata for org.springframework.transaction.ReactiveTransactionManager. Reason: java.lang.NoClassDefFoundError: reactor/core/publisher/Mono.
[INFO]     [creator]     WARNING: Could not register reflection metadata for org.springframework.boot.autoconfigure.transaction.jta.BitronixJtaConfiguration. Reason: java.lang.NoClassDefFoundError: bitronix/tm/Configuration.
[INFO]     [creator]     01:00:52.940 [ForkJoinPool-2-worker-1] DEBUG org.jboss.logging - Logging Provider: org.jboss.logging.Log4j2LoggerProvider
[INFO]     [creator]     Error: Image build request failed with exit status 137
[INFO]     [creator]     unable to invoke layer creator
[INFO]     [creator]     unable to contribute native-image layer
[INFO]     [creator]     error running build
[INFO]     [creator]     exit status 137
[INFO]     [creator]     ERROR: failed to build: exit status 1
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------

AOT编译不能分散、并行化，CPU和存储器都是瓶颈。也有原本就花费太多时间的问题。因为要解决只能准备高规格机器，所以能否导入频繁重复构建的开发项目还是个疑问。

交付给native image的参数为spring-boot-maven-pluggin的设定BP_NATIVE_IMAGE_BUILD_ARGUMENTS。结果，即使将堆尺寸指定为32GB也没有成功。原本，对于运行paketo-buildpacks容器的环境，也许32GB也没有分配存储器。

diff --git a/samples/data-jpa/pom.xml b/samples/data-jpa/pom.xml
index 4187cf63..b6535097 100644
--- a/samples/data-jpa/pom.xml
+++ b/samples/data-jpa/pom.xml
@@ -114,6 +114,14 @@
                        <plugin>
                                <groupId>org.springframework.boot</groupId>
                                <artifactId>spring-boot-maven-plugin</artifactId>
+                               <configuration>
+                                       <image>
+                                               <builder>paketobuildpacks/builder:tiny</builder>
+                                               <env>
+                                                       <BP_NATIVE_IMAGE_BUILD_ARGUMENTS>-J-Xmx32G</BP_NATIVE_IMAGE_BUILD_ARGUMENTS>
+                                               </env>
+                                       </image>
+                               </configuration>
                        </plugin>
                        <plugin>
                                <groupId>org.hibernate.orm.tooling</groupId>

但是，通过AWS EC2（r5.2xlarge，vCPU＝8，RAM=64GiB）执行。时间和资源都可以用金钱来解决。

$ uname -a
Linux ip-10-0-0-80.ap-northeast-1.compute.internal 4.14.219-164.354.amzn2.x86_64 #1 SMP Mon Feb 22 21:18:39 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux

$ free -h
              total        used        free      shared  buff/cache   available
Mem:            62G        504M         57G        500K        4.4G         61G
Swap:            0B          0B          0B

$ sudo yum update -y
$ sudo yum install -y git
$ sudo amazon-linux-extras install docker
$ sudo usermod -a -G docker ec2-user
$ sudo systemctl enable docker
$ sudo systemctl start docker
$ curl -s "https://get.sdkman.io" | bash
$ source ~/.sdkman/bin/sdkman-init.sh
$ sdk install java 21.0.0.2.r11-grl
$ sdk install maven install 3.6.3

成功了。内存需要9.3GB以上。

$ git clone https://github.com/spring-projects-experimental/spring-native
$ cd spring-native/samples/data-jpa
$ mvn spring-boot:build-image
<snip>
<snip>
<snip>
[INFO]     [creator]     [/layers/paketo-buildpacks_native-image/native-image/app.main.SampleApplication:176]     (clinit):   2,413.81 ms,  7.15 GB
[INFO]     [creator]     [/layers/paketo-buildpacks_native-image/native-image/app.main.SampleApplication:176]   (typeflow):  62,320.78 ms,  7.15 GB
[INFO]     [creator]     [/layers/paketo-buildpacks_native-image/native-image/app.main.SampleApplication:176]    (objects):  58,314.63 ms,  7.15 GB
[INFO]     [creator]     [/layers/paketo-buildpacks_native-image/native-image/app.main.SampleApplication:176]   (features):  11,451.10 ms,  7.15 GB
[INFO]     [creator]     [/layers/paketo-buildpacks_native-image/native-image/app.main.SampleApplication:176]     analysis: 140,293.14 ms,  7.15 GB
[INFO]     [creator]     [/layers/paketo-buildpacks_native-image/native-image/app.main.SampleApplication:176]     universe:   4,119.72 ms,  7.26 GB
[INFO]     [creator]     [/layers/paketo-buildpacks_native-image/native-image/app.main.SampleApplication:176]      (parse):   9,142.60 ms,  7.28 GB
[INFO]     [creator]     [/layers/paketo-buildpacks_native-image/native-image/app.main.SampleApplication:176]     (inline):  12,394.42 ms,  8.97 GB
[INFO]     [creator]     [/layers/paketo-buildpacks_native-image/native-image/app.main.SampleApplication:176]    (compile):  44,175.39 ms,  9.39 GB
[INFO]     [creator]     [/layers/paketo-buildpacks_native-image/native-image/app.main.SampleApplication:176]      compile:  71,024.26 ms,  9.39 GB
[INFO]     [creator]     [/layers/paketo-buildpacks_native-image/native-image/app.main.SampleApplication:176]        image:   8,853.52 ms,  9.30 GB
[INFO]     [creator]     [/layers/paketo-buildpacks_native-image/native-image/app.main.SampleApplication:176]        write:   1,264.68 ms,  9.30 GB
[INFO]     [creator]     [/layers/paketo-buildpacks_native-image/native-image/app.main.SampleApplication:176]      [total]: 233,022.78 ms,  9.30 GB
[INFO]     [creator]       Removing bytecode
[INFO]     [creator]       Process types:
[INFO]     [creator]         native-image: /workspace/app.main.SampleApplication (direct)
[INFO]     [creator]         task:         /workspace/app.main.SampleApplication (direct)
[INFO]     [creator]         web:          /workspace/app.main.SampleApplication (direct)
[INFO]     [creator]     ===> EXPORTING
[INFO]     [creator]     Adding 1/1 app layer(s)
[INFO]     [creator]     Adding layer 'launcher'
[INFO]     [creator]     Adding layer 'config'
[INFO]     [creator]     Adding layer 'process-types'
[INFO]     [creator]     Adding label 'io.buildpacks.lifecycle.metadata'
[INFO]     [creator]     Adding label 'io.buildpacks.build.metadata'
[INFO]     [creator]     Adding label 'io.buildpacks.project.metadata'
[INFO]     [creator]     Adding label 'org.opencontainers.image.title'
[INFO]     [creator]     Adding label 'org.opencontainers.image.version'
[INFO]     [creator]     Adding label 'org.springframework.boot.spring-configuration-metadata.json'
[INFO]     [creator]     Adding label 'org.springframework.boot.version'
[INFO]     [creator]     Setting default process type 'web'
[INFO]     [creator]     *** Images (cc33ab8d5de7):
[INFO]     [creator]           docker.io/library/data-jpa:0.0.1-SNAPSHOT
[INFO]     [creator]     Adding cache layer 'paketo-buildpacks/graalvm:jdk'
[INFO]     [creator]     Adding cache layer 'paketo-buildpacks/native-image:native-image'
[INFO]
[INFO] Successfully built image 'docker.io/library/data-jpa:0.0.1-SNAPSHOT'

比之前的例子稍大（137MB）。而且启动还是很快。Started SampleApplication in 0.114 seconds (JVM running for 0.115)

$ docker images | grep data-jpa
data-jpa                   0.0.1-SNAPSHOT      cc33ab8d5de7        41 years ago        137MB

$ docker run -d --name data-jpa -p 8080:8080 data-jpa:0.0.1-SNAPSHOT
e72516c73a31d90078c0b88effd2c9d9ab9c9ca5911bc18bd513f1d65c52baeb

$ docker logs --tail=10 data-jpa
2021-03-12 04:27:53.878  INFO 1 --- [           main] j.LocalContainerEntityManagerFactoryBean : Initialized JPA EntityManagerFactory for persistence unit 'default'
2021-03-12 04:27:53.903  WARN 1 --- [           main] JpaBaseConfiguration$JpaWebConfiguration : spring.jpa.open-in-view is enabled by default. Therefore, database queries may be performed during view rendering. Explicitly configure spring.jpa.open-in-view to disable this warning
2021-03-12 04:27:53.911  INFO 1 --- [           main] o.s.s.concurrent.ThreadPoolTaskExecutor  : Initializing ExecutorService 'applicationTaskExecutor'
2021-03-12 04:27:53.915  INFO 1 --- [           main] o.s.w.s.f.support.RouterFunctionMapping  : Mapped (GET && /) -> app.main.SampleApplication$$Lambda$1e60cb8412269e314b131e1c351c5acea34567f4@75858ac2
Mar 12, 2021 4:27:53 AM org.apache.coyote.AbstractProtocol start
INFO: Starting ProtocolHandler ["http-nio-8080"]
2021-03-12 04:27:53.923  INFO 1 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8080 (http) with context path ''
2021-03-12 04:27:53.924  INFO 1 --- [           main] app.main.SampleApplication               : Started SampleApplication in 0.114 seconds (JVM running for 0.115)

只有在接受第一个请求的时候才初始化dispatcherServlet。我觉得spring-boot-starter-webflumx和spring-boot-starter-web的初期构成是不同的。

$ curl -s localhost:8080/; echo
{"value":"Hello"}
$ curl -s localhost:8080/; echo
{"value":"Hello"}

$ docker logs --tail=10 data-jpa
2021-03-12 04:34:31.249  INFO 1 --- [           main] o.s.s.concurrent.ThreadPoolTaskExecutor  : Initializing ExecutorService 'applicationTaskExecutor'
2021-03-12 04:34:31.253  INFO 1 --- [           main] o.s.w.s.f.support.RouterFunctionMapping  : Mapped (GET && /) -> app.main.SampleApplication$$Lambda$1e60cb8412269e314b131e1c351c5acea34567f4@d127876
Mar 12, 2021 4:34:31 AM org.apache.coyote.AbstractProtocol start
INFO: Starting ProtocolHandler ["http-nio-8080"]
2021-03-12 04:34:31.262  INFO 1 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8080 (http) with context path ''
2021-03-12 04:34:31.262  INFO 1 --- [           main] app.main.SampleApplication               : Started SampleApplication in 0.115 seconds (JVM running for 0.116)
Mar 12, 2021 4:35:04 AM org.apache.catalina.core.ApplicationContext log
INFO: Initializing Spring DispatcherServlet 'dispatcherServlet'
2021-03-12 04:35:04.896  INFO 1 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : Initializing Servlet 'dispatcherServlet'
2021-03-12 04:35:04.897  INFO 1 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : Completed initialization in 1 ms

通过Spring Initializa创建项目

通过Spring Initializa选择以下组件来创建项目

spring-native
spring-boot-starter-web
spring-boot-starter-security
spring-boot-starter-data-jpa
h2

$ curl -fsSL --output demo.zip 'https://www.dropbox.com/s/xn0nfhqjb86lxp6/demo.zip?dl=0'
$ unzip -q demo.zip
$ cd demo
$ mvn spring-boot:build-image
<snip>
<snip>
<snip>
[INFO]     [creator]     [/layers/paketo-buildpacks_native-image/native-image/com.example.demo.DemoApplication:162]     (clinit):   2,669.42 ms,  5.99 GB
[INFO]     [creator]     [/layers/paketo-buildpacks_native-image/native-image/com.example.demo.DemoApplication:162]   (typeflow):  54,900.98 ms,  5.99 GB
[INFO]     [creator]     [/layers/paketo-buildpacks_native-image/native-image/com.example.demo.DemoApplication:162]    (objects):  84,588.13 ms,  5.99 GB
[INFO]     [creator]     [/layers/paketo-buildpacks_native-image/native-image/com.example.demo.DemoApplication:162]   (features):  13,431.18 ms,  5.99 GB
[INFO]     [creator]     [/layers/paketo-buildpacks_native-image/native-image/com.example.demo.DemoApplication:162]     analysis: 162,606.05 ms,  5.99 GB
[INFO]     [creator]     [/layers/paketo-buildpacks_native-image/native-image/com.example.demo.DemoApplication:162]     universe:   4,543.12 ms,  5.88 GB
[INFO]     [creator]     [/layers/paketo-buildpacks_native-image/native-image/com.example.demo.DemoApplication:162]      (parse):  15,612.61 ms,  6.90 GB
[INFO]     [creator]     [/layers/paketo-buildpacks_native-image/native-image/com.example.demo.DemoApplication:162]     (inline):  18,884.95 ms,  8.12 GB
[INFO]     [creator]     [/layers/paketo-buildpacks_native-image/native-image/com.example.demo.DemoApplication:162]    (compile):  53,247.44 ms,  8.66 GB
[INFO]     [creator]     [/layers/paketo-buildpacks_native-image/native-image/com.example.demo.DemoApplication:162]      compile:  95,278.63 ms,  8.71 GB
[INFO]     [creator]     [/layers/paketo-buildpacks_native-image/native-image/com.example.demo.DemoApplication:162]        image:  13,747.40 ms,  8.72 GB
[INFO]     [creator]     [/layers/paketo-buildpacks_native-image/native-image/com.example.demo.DemoApplication:162]        write:   1,646.05 ms,  8.72 GB
[INFO]     [creator]     [/layers/paketo-buildpacks_native-image/native-image/com.example.demo.DemoApplication:162]      [total]: 284,598.43 ms,  8.72 GB
[INFO]     [creator]       Removing bytecode
[INFO]     [creator]       Process types:
[INFO]     [creator]         native-image: /workspace/com.example.demo.DemoApplication (direct)
[INFO]     [creator]         task:         /workspace/com.example.demo.DemoApplication (direct)
[INFO]     [creator]         web:          /workspace/com.example.demo.DemoApplication (direct)
[INFO]     [creator]     ===> EXPORTING
[INFO]     [creator]     Adding 1/1 app layer(s)
[INFO]     [creator]     Reusing layer 'launcher'
[INFO]     [creator]     Adding layer 'config'
[INFO]     [creator]     Reusing layer 'process-types'
[INFO]     [creator]     Adding label 'io.buildpacks.lifecycle.metadata'
[INFO]     [creator]     Adding label 'io.buildpacks.build.metadata'
[INFO]     [creator]     Adding label 'io.buildpacks.project.metadata'
[INFO]     [creator]     Adding label 'org.opencontainers.image.title'
[INFO]     [creator]     Adding label 'org.opencontainers.image.version'
[INFO]     [creator]     Adding label 'org.springframework.boot.spring-configuration-metadata.json'
[INFO]     [creator]     Adding label 'org.springframework.boot.version'
[INFO]     [creator]     Setting default process type 'web'
[INFO]     [creator]     *** Images (745609869101):
[INFO]     [creator]           com.example/demo:0.0.1-SNAPSHOT
[INFO]     [creator]     Reusing cache layer 'paketo-buildpacks/graalvm:jdk'
[INFO]     [creator]     Adding cache layer 'paketo-buildpacks/native-image:native-image'
[INFO]
[INFO] Successfully built image 'com.example/demo:0.0.1-SNAPSHOT'

比之前的例子稍大（176MB）。而且启动还是很快。Started DemoApplication in 0.248 seconds (JVM running for 0.249)

$ docker images com.example/demo
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
com.example/demo    0.0.1-SNAPSHOT      745609869101        41 years ago        176MB

$ docker run -d --name demo -p 8080:8080 com.example/demo:0.0.1-SNAPSHOT
e72516c73a31d90078c0b88effd2c9d9ab9c9ca5911bc18bd513f1d65c52baeb

$ docker logs --tail=10 demo
Hibernate: create sequence hibernate_sequence start with 1 increment by 1
2021-03-12 07:26:02.561  INFO 1 --- [           main] o.h.e.t.j.p.i.JtaPlatformInitiator       : HHH000490: Using JtaPlatform implementation: [org.hibernate.engine.transaction.jta.platform.internal.NoJtaPlatform]
2021-03-12 07:26:02.561  INFO 1 --- [           main] j.LocalContainerEntityManagerFactoryBean : Initialized JPA EntityManagerFactory for persistence unit 'default'
2021-03-12 07:26:02.586  WARN 1 --- [           main] JpaBaseConfiguration$JpaWebConfiguration : spring.jpa.open-in-view is enabled by default. Therefore, database queries may be performed during view rendering. Explicitly configure spring.jpa.open-in-view to disable this warning
2021-03-12 07:26:02.689  INFO 1 --- [           main] o.s.s.web.DefaultSecurityFilterChain     : Will secure any request with [org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter@60450f0a, org.springframework.security.web.context.SecurityContextPersistenceFilter@5494e33d, org.springframework.security.web.header.HeaderWriterFilter@47241e24, org.springframework.security.web.authentication.logout.LogoutFilter@66bb42a0, org.springframework.security.web.authentication.www.BasicAuthenticationFilter@722091c3, org.springframework.security.web.savedrequest.RequestCacheAwareFilter@61ff4cbb, org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter@1efca9f3, org.springframework.security.web.authentication.AnonymousAuthenticationFilter@233b0d7a, org.springframework.security.web.session.SessionManagementFilter@531dc996, org.springframework.security.web.access.ExceptionTranslationFilter@4542c3e3, org.springframework.security.web.access.intercept.FilterSecurityInterceptor@439ab877]
2021-03-12 07:26:02.697  INFO 1 --- [           main] o.s.s.concurrent.ThreadPoolTaskExecutor  : Initializing ExecutorService 'applicationTaskExecutor'
Mar 12, 2021 7:26:02 AM org.apache.coyote.AbstractProtocol start
INFO: Starting ProtocolHandler ["http-nio-8080"]
2021-03-12 07:26:02.711  INFO 1 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8080 (http) with context path ''
2021-03-12 07:26:02.712  INFO 1 --- [           main] com.example.demo.DemoApplication         : Started DemoApplication in 0.248 seconds (JVM running for 0.249)

原文地址：https://yujiorama.hatenablog.com/entry/2021/03/13/064824