blue
Estimated time: 15 minutes
References:
In this lab, the objective is to create a simple Spring Boot application that will be enhanced progressively in the next sections.
Use the Spring Initializr online tool to generate a simple simple Web application with the following dependencies
Fill the form with the following details.
Group: com.oracle.graalvm.demo
Artifact: hello-spring-boot-app
Description : Demo Spring App with GraalVM
Package Name: com.oracle.graalvm.demo.hello-spring-boot-app
Packaging: Jar
Java: 11
Add Spring Web and Spring Boot Actuator Dependencies.
Click on the 
to download the project structure.
Unzip the generated project template and open it in your favorite Editor.
Now the code is ready for modifications.
References:
In this section just add the following REST Controller
package com.oracle.graalvm.demo.hellospringbootapp;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class HelloController {
@GetMapping("/")
public String index() {
return "Welcome to GraalVM Spring Boot HOL!\n";
}
}Make sure we are running with GraalVM
$ java -version
java version "11.0.13" 2021-10-19 LTS
Java(TM) SE Runtime Environment GraalVM EE 21.3.0 (build 11.0.13+10-LTS-jvmci-21.3-b05)
Java HotSpot(TM) 64-Bit Server VM GraalVM EE 21.3.0 (build 11.0.13+10-LTS-jvmci-21.3-b05, mixed mode, sharing)
Add a Unit Test
package com.oracle.graalvm.demo.hellospringbootapp;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.boot.test.web.client.TestRestTemplate;
import org.springframework.http.ResponseEntity;
import static org.assertj.core.api.Assertions.assertThat;
@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
public class HelloControllerIT {
@Autowired
private TestRestTemplate template;
@Test
public void getHello() throws Exception {
ResponseEntity<String> response = template.getForEntity("/", String.class);
assertThat(response.getBody()).isEqualTo("Welcome to GraalVM Spring Boot HOL!");
}
}In this section we are building the application to produce a JAR File. this Jar file will be launch using a JRE USe Gradle or Maven to build your application
$ ./mvnw package
..
INFO] Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 3.088 s - in com.oracle.graalvm.demo.hellospringbootapp.HelloSpringBootAppApplicationTests
[INFO]
[INFO] Results:
[INFO]
[INFO] Tests run: 1, Failures: 0, Errors: 0, Skipped: 0
[INFO]
[INFO]
[INFO] --- maven-jar-plugin:3.2.0:jar (default-jar) @ hello-spring-boot-app ---
[INFO] Building jar: /Users/nono/Projects/Workshops/EMEA-HOL-SpringBoot/hello-spring-boot-app/target/hello-spring-boot-app-0.0.1-SNAPSHOT.jar
[INFO]
[INFO] --- spring-boot-maven-plugin:2.5.6:repackage (repackage) @ hello-spring-boot-app ---
[INFO] Replacing main artifact with repackaged archive
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 7.503 s
[INFO] Finished at: 2021-11-04T15:27:32+01:00
[INFO] ------------------------------------------------------------------------GraalVM comes with a new JIT compiler
$ java -jar target/hello-spring-boot-app-0.0.1-SNAPSHOT.jarSend 30000 requests to your application with a concurrency level 100 with Apache Bench or another load tester tool.
$ ab -n 30000 -c 100 http://localhost:8080/
This is ApacheBench, Version 2.3 <$Revision: 1879490 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/
Concurrency Level: 100
Time taken for tests: 58.214 seconds
Complete requests: 30000
Failed requests: 0
Total transferred: 5070000 bytes
HTML transferred: 1080000 bytes
Requests per second: 515.34 [#/sec] (mean)
Time per request: 194.047 [ms] (mean)
Time per request: 1.940 [ms] (mean, across all concurrent requests)
Transfer rate: 85.05 [Kbytes/sec] received
Connection Times (ms)
min mean[+/-sd] median max
Connect: 0 171 1486.9 22 19323
Processing: 0 22 21.9 19 508
Waiting: 0 21 21.5 18 506
Total: 0 194 1486.1 43 19323
Percentage of the requests served within a certain time (ms)
50% 43
66% 51
75% 58
80% 62
90% 69
95% 107
98% 164
99% 11363
100% 19323 (longest request)Restart the application without Graal Compiler
java -XX:-UseJVMCICompiler target/hello-spring-boot-app-0.0.1-SNAPSHOT.jarSend the same load to the application instance without Graal Compliler
$ ab -n 30000 -c 100 http://localhost:8080/
Concurrency Level: 100
Time taken for tests: 60.561 seconds
Complete requests: 30000
Failed requests: 0
Total transferred: 5070000 bytes
HTML transferred: 1080000 bytes
Requests per second: 495.37 [#/sec] (mean)
Time per request: 201.869 [ms] (mean)
Time per request: 2.019 [ms] (mean, across all concurrent requests)
Transfer rate: 81.76 [Kbytes/sec] received
Connection Times (ms)
min mean[+/-sd] median max
Connect: 0 177 1536.7 22 19308
Processing: 0 24 32.1 21 467
Waiting: 0 24 31.9 20 465
Total: 1 201 1535.6 46 19309
Percentage of the requests served within a certain time (ms)
50% 46
66% 54
75% 61
80% 63
90% 70
95% 83
98% 311
99% 11199
100% 19309 (longest request)
By Running this simple helloworld application with GraalVM JIT, we can handle +20 requests per second in average
Existing applications can leverage GraalVM JIT to accelerate their performances whitout having to change any line of code.
Next, we'll try to explore Native images build for this application.
