我们正在使用 openJDK11.0.6 java.net.http HTTP (HTTP1.1) 客户端从网站获取内容。经过长时间的执行，我们注意到性能下降。即使应用程序什么都不做，CPU 也会 100% 使用。我们能够确定它来自很多应用程序泄漏的套接字（CLOSE-WAIT 状态）。
这里已经有一些关于它的问题（比如这个），但是所有提交的错误都应该被修复并向后移植到 java 11.0.6。
我已经能够将该错误重现到github 上的 minalist 项目中。似乎只有当客户端从服务器收到 204 NO-CONTENT 时才会发生这种情况。
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpClient.Version;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.net.http.HttpResponse.BodyHandlers;
public class BasicFetcherApp {
public static void main(String[] args) throws Exception {
System.out.println("App is running... pid: " + ProcessHandle.current().pid());
HttpClient client = HttpClient.newBuilder().version(Version.HTTP_1_1).build();
for (int i = 0; i < 10; ++i) {
HttpRequest request =
HttpRequest.newBuilder(URI.create("http://localhost:4001/nocontent")).build();
HttpResponse<String> response = client.send(request, BodyHandlers.ofString());
System.out.println(String.format("Response HTTP status: %s", response.statusCode()));
}
System.out.println("Finish");
System.in.read();
}
}
如果我们运行它：
App is running... pid: 23306
Response HTTP status: 204
Response HTTP status: 204
Response HTTP status: 204
Response HTTP status: 204
Response HTTP status: 204
Response HTTP status: 204
Response HTTP status: 204
Response HTTP status: 204
Response HTTP status: 204
Response HTTP status: 204
Finish
ss -np | grep 23306
u_str ESTAB 0 0 * 4121660 * 0 users:(("java",pid=23306,fd=13))
u_str ESTAB 0 0 * 4121047 * 0 users:(("java",pid=23306,fd=6))
tcp ESTAB 0 0 [::ffff:127.0.0.1]:56666 [::ffff:127.0.0.1]:40177 users:(("java",pid=23306,fd=7))
tcp CLOSE-WAIT 1 0 [::ffff:127.0.0.1]:58592 [::ffff:127.0.0.1]:4001 users:(("java",pid=23306,fd=24))
tcp CLOSE-WAIT 1 0 [::ffff:127.0.0.1]:58570 [::ffff:127.0.0.1]:4001 users:(("java",pid=23306,fd=18))
tcp CLOSE-WAIT 1 0 [::ffff:127.0.0.1]:58572 [::ffff:127.0.0.1]:4001 users:(("java",pid=23306,fd=19))
tcp CLOSE-WAIT 1 0 [::ffff:127.0.0.1]:58564 [::ffff:127.0.0.1]:4001 users:(("java",pid=23306,fd=15))
tcp CLOSE-WAIT 1 0 [::ffff:127.0.0.1]:58560 [::ffff:127.0.0.1]:4001 users:(("java",pid=23306,fd=14))
tcp CLOSE-WAIT 1 0 [::ffff:127.0.0.1]:58574 [::ffff:127.0.0.1]:4001 users:(("java",pid=23306,fd=20))
tcp CLOSE-WAIT 1 0 [::ffff:127.0.0.1]:58582 [::ffff:127.0.0.1]:4001 users:(("java",pid=23306,fd=21))
tcp CLOSE-WAIT 1 0 [::ffff:127.0.0.1]:58590 [::ffff:127.0.0.1]:4001 users:(("java",pid=23306,fd=23))
tcp CLOSE-WAIT 1 0 [::ffff:127.0.0.1]:58594 [::ffff:127.0.0.1]:4001 users:(("java",pid=23306,fd=25))
tcp CLOSE-WAIT 1 0 [::ffff:127.0.0.1]:58584 [::ffff:127.0.0.1]:4001 users:(("java",pid=23306,fd=22))
OpenJDK 错误（已修复）：