springBoot3.2 + jdk21 + GraalVM上手体验
SpringBoot2.x官方已经停止维护了，jdk8这次真的得换了🤣 
- 可以参考官方文章进行体验：spring.io/blog/2023/0...
- 通过官方快速得到一个基于jdk21的项目：start.spring.io/
快速体验（二进制部署）
typescript
@RestController
@SpringBootApplication
public class DemoApplication {
public static void main(String[] args) {
SpringApplication.run(DemoApplication.class, args);
}
@GetMapping("/customers")
Collection<Customer> customers() {
return Set.of(new Customer(1, "A"), new Customer(2, "B"), new Customer(3, "C"));
}
record Customer(Integer id, String name) {
}
}启动非常快，秒启动
压测环境内存占用大概70MB左右，空闲时在20MB左右（由于直接打成二进制文件了，不能再使用jconsole、arthas之类的进行监控了），性能上由于不需要JVM预热，性能启动即巅峰。
yaml
$ ab -c 50 -n 10000 http://localhost:8080/customers
Server Software:
Server Hostname: localhost
Server Port: 8080
Document Path: /customers
Document Length: 61 bytes
Concurrency Level: 50
Time taken for tests: 1.413 seconds
Complete requests: 10000
Failed requests: 0
Total transferred: 1660000 bytes
HTML transferred: 610000 bytes
Requests per second: 7076.39 [#/sec] (mean)
Time per request: 7.066 [ms] (mean)
Time per request: 0.141 [ms] (mean, across all concurrent requests)
Transfer rate: 1147.15 [Kbytes/sec] received
Connection Times (ms)
min mean[+/-sd] median max
Connect: 0 2 8.0 2 144
Processing: 1 5 6.7 4 147
Waiting: 0 4 5.6 3 145
Total: 1 7 10.4 6 149
快速体验（jar部署）
jar包占用只有19MB，已经不能算是小胖jar了😊
内存占用在压测时大概在200MB左右，空闲时在160MB左右。性能显然也不是启动即巅峰，可以看出其实还是需要进行JVM预热才能达到性能巅峰的
yaml
$ ab -c 50 -n 10000 http://localhost:8080/customers
Server Software:
Server Hostname: localhost
Server Port: 8080
Document Path: /customers
Document Length: 61 bytes
Concurrency Level: 50
Time taken for tests: 17.930 seconds
Complete requests: 10000
Failed requests: 0
Total transferred: 1660000 bytes
HTML transferred: 610000 bytes
Requests per second: 557.72 [#/sec] (mean)
Time per request: 89.651 [ms] (mean)
Time per request: 1.793 [ms] (mean, across all concurrent requests)
Transfer rate: 90.41 [Kbytes/sec] received
Connection Times (ms)
min mean[+/-sd] median max
Connect: 0 38 430.2 2 7004
Processing: 0 14 90.4 8 1773
Waiting: 0 12 88.7 6 1771
Total: 1 53 439.0 10 7011
对比golang
go
package main
import (
"encoding/json"
"flag"
"fmt"
"net/http"
)
var port = flag.String("p", "8080", "please input port")
func main() {
http.HandleFunc("/customers", func(writer http.ResponseWriter, request *http.Request) {
data, _ := json.Marshal(request.URL)
writer.Write(data)
})
e := make(chan error)
go func() {
e <- fmt.Errorf("error[%v]", http.ListenAndServe(":"+*port, nil))
}()
fmt.Println("http 服务器启动...")
fmt.Println(<-e)
}这里golang没有使用框架，仅使用标准库，所以内存占用较低，仅10MB左右，不过即使使用Gin之类的web框架，内存也不会超过20MB
yaml
$ ab -c 50 -n 10000 http://localhost:8080/customers
Server Software:
Server Hostname: localhost
Server Port: 8080
Document Path: /customers
Document Length: 161 bytes
Concurrency Level: 50
Time taken for tests: 1.380 seconds
Complete requests: 10000
Failed requests: 0
Total transferred: 2790000 bytes
HTML transferred: 1610000 bytes
Requests per second: 7247.68 [#/sec] (mean)
Time per request: 6.899 [ms] (mean)
Time per request: 0.138 [ms] (mean, across all concurrent requests)
Transfer rate: 1974.71 [Kbytes/sec] received
Connection Times (ms)
min mean[+/-sd] median max
Connect: 0 2 16.5 2 459
Processing: 0 4 27.9 2 460
Waiting: 0 2 10.5 2 459
Total: 1 7 32.3 4 462
结论
AOT-processed已经相对成熟，效果可以说非常惊艳，解决了JVM启动慢、需要预热、内存占用大等问题。
美中不足的是编译速度非常慢，笔者电脑是2017款mac book pro编译花费大概15分钟左右
csharp
Finished generating 'demo' in 14m 33s.
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 15:45 min
[INFO] Finished at: 2023-12-01T17:00:21+08:00
[INFO] ------------------------------------------------------------------------INFO\] Total time: 15:45 min \[INFO\] Finished at: 2023-12-01T17:00:21+08:00 \[INFO\] ------------------------------------------------------------------------ 可以看出java在云原生大环境下已经取得了不错的进步的