Concurrency 为什么可以'；t在建立httpSession后，Wildfly服务器处理并发REST请求

我遇到了一个我正试图理解的难题。我已经实现了一个在Wildfly服务器中运行的非常简单的REST服务示例。我有一个独立的多线程Java测试程序，它使用ApacheHTTP客户端库访问服务。客户端程序有两个独立的线程同时访问REST服务。当在服务器上运行测试程序而不建立httpSession时，服务器会并发处理请求（如服务器日志中所示）。如果线程是在建立httpSession之后运行的，则服务器将以顺序方式处理请求（如第二个服务器日志所示）。请注意，两个线程共享一个会话

这是故意的吗？我错过了什么？提前谢谢

以下是我的环境的基本要素：

• Wildfly服务器信息：Wildfly-17.0.0.Final在Windows 10上运行，使用 standalone-ha.xml中指定的独立、高可用性配置
• 客户端信息：Apache http客户端4.5.5（托管版本）

---

以下是代表这两种情况的服务器日志：

Server log when no http session is established.  
Requests run concurrently when there is no session.

13:39:13,384 INFO  (default task-5) Getting widget 3  
13:39:13,384 INFO  (default task-6) Getting widget 4  
13:39:13,384 INFO  (default task-6) DELAYING widget 4  
13:39:13,384 INFO  (default task-5) Returning widget 3  
13:39:13,404 INFO  (default task-6) DELAY COMPLETE widget 4  
13:39:13,404 INFO  (default task-6) Returning widget 4  
13:39:13,408 INFO  (default task-6) Getting widget 3  
13:39:13,408 INFO  (default task-6) Returning widget 3  
13:39:13,409 INFO  (default task-5) Getting widget 4  
13:39:13,409 INFO  (default task-5) DELAYING widget 4  
13:39:13,413 INFO  (default task-6) Getting widget 3  
13:39:13,413 INFO  (default task-6) Returning widget 3  
13:39:13,419 INFO  (default task-6) Getting widget 3  
13:39:13,419 INFO  (default task-6) Returning widget 3  
13:39:13,425 INFO  (default task-6) Getting widget 3  
13:39:13,425 INFO  (default task-6) Returning widget 3  
13:39:13,430 INFO  (default task-6) Getting widget 3  
13:39:13,430 INFO  (default task-6) Returning widget 3  
13:39:13,436 INFO  (default task-5) DELAY COMPLETE widget 4  
13:39:13,436 INFO  (default task-5) Returning widget 4  
13:39:13,436 INFO  (default task-6) Getting widget 3  
13:39:13,436 INFO  (default task-6) Returning widget 3  
13:39:13,441 INFO  (default task-6) Getting widget 4  
13:39:13,441 INFO  (default task-5) Getting widget 3  
13:39:13,442 INFO  (default task-6) DELAYING widget 4  
13:39:13,442 INFO  (default task-5) Returning widget 3  
13:39:13,447 INFO  (default task-5) Getting widget 3  
13:39:13,447 INFO  (default task-5) Returning widget 3  
...

这是REST服务的实现

@Path("concurrencyTest")
@Stateless
public class ConcurrencyTestWs extends BaseWs {
  private static final Logger log = LoggerFactory
      .getLogger(ConcurrencyTestWs.class);

  @SuppressWarnings("static-method")
  @GET
  @Path("/widget")
  public Response getWidget(@Context HttpServletRequest request,
      @QueryParam(value = "widgetId") Long widgetId) {
    try {
      log.info(String.format("Getting widget %d", widgetId));
      if ((widgetId % 2) == 0) {
        log.info(String.format("DELAYING widget %d", widgetId));
        try {
          Thread.sleep(20);
        } catch (Exception e) {
          System.err.println(e.getMessage());
        }
        log.info(String.format("DELAY COMPLETE widget %d", widgetId));
      }
      log.info(String.format("Returning widget %d", widgetId));
      return Response.ok(String.format("Widget %d retrieved", widgetId))
          .build();
    } catch (Exception e) {
      return RestUtilities.getInternalError(request, "Widget", widgetId, e);
    }
  }

  @SuppressWarnings("static-method")
  @POST
  @Path("/establishSession")
  public Response establishSession(@Context HttpServletRequest request) {
    try {
      HttpSession session = request.getSession(true);
      log.info(String.format("Session established %s", session.getId()));
      Response response = Response.ok().build();
      return response;
    } catch (Exception e) {
      return RestUtilities.getInternalError(request, e);
    }
  }

  @SuppressWarnings("static-method")
  @POST
  @Path("/terminateSession")
  public Response terminateSession(@Context HttpServletRequest request) {
    try {
      HttpSession session = request.getSession(false);
      log.info(String.format("Terminating session %s",
          (session == null) ? "null" : session.getId()));
      Response response = Response.ok().build();
      return response;
    } catch (Exception e) {
      return RestUtilities.getInternalError(request, e);
    }
  }

}

这是客户端源代码

public class WidgetFetchTest {

  private final static String restServiceUrl = "http://dtp002.novodynamics.com:8081/TEST/REST/v1.0/concurrencyTest";
  private final CloseableHttpClient httpClient;
  private final CookieStore cookieStore;

  public WidgetFetchTest() {
    this.cookieStore = new BasicCookieStore();

    RequestConfig requestConfig = RequestConfig.custom()
        .setConnectTimeout(60000).setConnectionRequestTimeout(60000)
        .setSocketTimeout(60000).setCookieSpec(CookieSpecs.STANDARD).build();

    @SuppressWarnings("resource")
    PoolingHttpClientConnectionManager connectionManager = new PoolingHttpClientConnectionManager();
    connectionManager.setMaxTotal(100);
    connectionManager.setDefaultMaxPerRoute(40);

    this.httpClient = HttpClients.custom()
        .setDefaultRequestConfig(requestConfig)
        .setDefaultCookieStore(this.cookieStore)
        .setConnectionManager(connectionManager).build();
  }

  public void run() {
    establishSession(this.httpClient);
    DocFetchRunnable r1 = new DocFetchRunnable("4", this.httpClient);
    DocFetchRunnable r2 = new DocFetchRunnable("3", this.httpClient);
    ExecutorService exec = Executors.newFixedThreadPool(2);
    exec.execute(r1);
    exec.execute(r2);
    try {
      Thread.sleep(60000);
    } catch (InterruptedException e) {
      e.printStackTrace();
    }

  }

  protected static void establishSession(CloseableHttpClient client) {
    try {
      URIBuilder ub = new URIBuilder(
          String.format("%s%s", restServiceUrl, "/establishSession"));
      String url = ub.toString();
      HttpContext ctx = HttpClientContext.create();
      try (CloseableHttpResponse response = client.execute(new HttpPost(url),
          ctx)) {
        // intentionally empty.
      } catch (Exception e) {
        e.printStackTrace();
      }
    } catch (URISyntaxException e) {
      e.printStackTrace();
    }
  }

  protected static void getWidget(CloseableHttpClient client, String widgetId) {
    try {
      URIBuilder ub = new URIBuilder(
          String.format("%s%s", restServiceUrl, "/widget"));
      ub.addParameter("widgetId", widgetId);
      String url = ub.toString();
      HttpContext ctx = HttpClientContext.create();
      try (CloseableHttpResponse response = client.execute(new HttpGet(url),
          ctx)) {
        // intentionally empty.
      } catch (Exception e) {
        e.printStackTrace();
      }
    } catch (URISyntaxException e) {
      e.printStackTrace();
    }
  }

  private class DocFetchRunnable implements Runnable {
    private String widgetId;
    CloseableHttpClient client;

    public DocFetchRunnable(String widgetId, CloseableHttpClient client) {
      this.widgetId = widgetId;
      this.client = client;
    }

    @Override
    public void run() {
      for (int i = 0; i < 50; i++) {
        System.out.println(
            String.format("Fetching widget %s - %d", this.widgetId, i));
        System.out.flush();
        getWidget(this.client, this.widgetId);
        System.out.println(
            String.format("Widget fetched  %s - %d", this.widgetId, i));
        System.out.flush();
      }
    }
  }

  public static void main(String[] args) {
    WidgetFetchTest dft = new WidgetFetchTest();
    dft.run();
    System.exit(0);
  }
}

公共类WidgetFetchTest{
私有最终静态字符串restServiceUrl=”http://dtp002.novodynamics.com:8081/TEST/REST/v1.0/concurrencyTest";
私有最终可关闭httpClient httpClient；
私人最终CookieStore CookieStore；
公共WidgetFetchTest（）{
this.cookieStore=new BasicCookieStore（）；
RequestConfig RequestConfig=RequestConfig.custom（）
.setConnectTimeout（60000）.setConnectionRequestTimeout（60000）
.setSocketTimeout（60000）.setCookiesSpec（CookiesSpec.STANDARD）.build（）；
@抑制警告（“资源”）
PoolighttpClientConnectionManager connectionManager=新的PoolighttpClientConnectionManager（）；
connectionManager.setMaxTotal（100）；
connectionManager.setDefaultMaxPerRoute（40）；
this.httpClient=HttpClients.custom（）
.setDefaultRequestConfig（requestConfig）
.setDefaultCookieStore（this.cookieStore）
.setConnectionManager（connectionManager.build（）；
}
公开募捐{
建立会话（this.httpClient）；
DocFetchRunnable r1=新的DocFetchRunnable（“4”，this.httpClient）；
DocFetchRunnable r2=新的DocFetchRunnable（“3”，this.httpClient）；
ExecutorService exec=Executors.newFixedThreadPool（2）；
exec.execute（r1）；
exec.execute（r2）；
试一试{
睡眠（60000）；
}捕捉（中断异常e）{
e、 printStackTrace（）；
}
}
受保护的静态会话（CloseableHttpClient客户端）{
试一试{
URIBuilder ub=新的URIBuilder(
格式（“%s%s”，restServiceUrl，“/establishSession”）；
字符串url=ub.toString（）；
HttpContext ctx=HttpClientContext.create（）；
try（CloseableHttpResponse response=client.execute）（新的HttpPost（url），
（ctx）{
//故意空的。
}捕获（例外e）{
e、 printStackTrace（）；
}
}捕获（URISyntaxException e）{
e、 printStackTrace（）；
}
}
受保护的静态void getWidget（CloseableHttpClient客户端，字符串widgetId）{
试一试{
URIBuilder ub=新的URIBuilder(
格式（“%s%s”，restServiceUrl，“/widget”）；
ub.addParameter（“widgetId”，widgetId）；
字符串url=ub.toString（）；
HttpContext ctx=HttpClientContext.create（）；
try（CloseableHttpResponse response=client.execute）（新的HttpGet（url），
（ctx）{
//故意空的。
}捕获（例外e）{
e、 printStackTrace（）；
}
}捕获（URISyntaxException e）{
e、 printStackTrace（）；
}
}
私有类DocFetchRunnable实现Runnable{
私有字符串widgetId；
可关闭的httpclient；
公共DocFetchRunnable（字符串widgetId，CloseableHttpClient客户端）{
this.widgetId=widgetId；
this.client=client；
}
@凌驾
公开募捐{
对于（int i=0；i<50；i++）{
System.out.println(
format（“获取小部件%s-%d”，this.widgetId，i））；
System.out.flush（）；
getWidget（this.client，this.widgetId）；
System.out.println(
format（“小部件获取了%s-%d”，this.widgetId，i））；
System.out.flush（）；
}
}
}
公共静态void main（字符串[]args）{
WidgetFetchTest dft=新的WidgetFetchTest（）；
dft.run（）；
系统出口（0）；
}
}

在JBossDeveloper论坛上发布此问题后，提供了以下答案

请参阅文档中有关会话并发性的部分：

通过将可重复读取与关联缓存配置上提交的读取之间的隔离放宽，可以解决此问题

public class WidgetFetchTest {

  private final static String restServiceUrl = "http://dtp002.novodynamics.com:8081/TEST/REST/v1.0/concurrencyTest";
  private final CloseableHttpClient httpClient;
  private final CookieStore cookieStore;

  public WidgetFetchTest() {
    this.cookieStore = new BasicCookieStore();

    RequestConfig requestConfig = RequestConfig.custom()
        .setConnectTimeout(60000).setConnectionRequestTimeout(60000)
        .setSocketTimeout(60000).setCookieSpec(CookieSpecs.STANDARD).build();

    @SuppressWarnings("resource")
    PoolingHttpClientConnectionManager connectionManager = new PoolingHttpClientConnectionManager();
    connectionManager.setMaxTotal(100);
    connectionManager.setDefaultMaxPerRoute(40);

    this.httpClient = HttpClients.custom()
        .setDefaultRequestConfig(requestConfig)
        .setDefaultCookieStore(this.cookieStore)
        .setConnectionManager(connectionManager).build();
  }

  public void run() {
    establishSession(this.httpClient);
    DocFetchRunnable r1 = new DocFetchRunnable("4", this.httpClient);
    DocFetchRunnable r2 = new DocFetchRunnable("3", this.httpClient);
    ExecutorService exec = Executors.newFixedThreadPool(2);
    exec.execute(r1);
    exec.execute(r2);
    try {
      Thread.sleep(60000);
    } catch (InterruptedException e) {
      e.printStackTrace();
    }

  }

  protected static void establishSession(CloseableHttpClient client) {
    try {
      URIBuilder ub = new URIBuilder(
          String.format("%s%s", restServiceUrl, "/establishSession"));
      String url = ub.toString();
      HttpContext ctx = HttpClientContext.create();
      try (CloseableHttpResponse response = client.execute(new HttpPost(url),
          ctx)) {
        // intentionally empty.
      } catch (Exception e) {
        e.printStackTrace();
      }
    } catch (URISyntaxException e) {
      e.printStackTrace();
    }
  }

  protected static void getWidget(CloseableHttpClient client, String widgetId) {
    try {
      URIBuilder ub = new URIBuilder(
          String.format("%s%s", restServiceUrl, "/widget"));
      ub.addParameter("widgetId", widgetId);
      String url = ub.toString();
      HttpContext ctx = HttpClientContext.create();
      try (CloseableHttpResponse response = client.execute(new HttpGet(url),
          ctx)) {
        // intentionally empty.
      } catch (Exception e) {
        e.printStackTrace();
      }
    } catch (URISyntaxException e) {
      e.printStackTrace();
    }
  }

  private class DocFetchRunnable implements Runnable {
    private String widgetId;
    CloseableHttpClient client;

    public DocFetchRunnable(String widgetId, CloseableHttpClient client) {
      this.widgetId = widgetId;
      this.client = client;
    }

    @Override
    public void run() {
      for (int i = 0; i < 50; i++) {
        System.out.println(
            String.format("Fetching widget %s - %d", this.widgetId, i));
        System.out.flush();
        getWidget(this.client, this.widgetId);
        System.out.println(
            String.format("Widget fetched  %s - %d", this.widgetId, i));
        System.out.flush();
      }
    }
  }

  public static void main(String[] args) {
    WidgetFetchTest dft = new WidgetFetchTest();
    dft.run();
    System.exit(0);
  }
}