Servlets Tomcat7:异步Servlet不工作
我已经将Tomcat7配置为一个连接器线程，将作业发布到后台线程池中，后台线程异步完成请求。每个请求都有1秒的延迟。我的测试（JMeter）向上旋转5个线程并同时发出5个请求。我希望单连接器线程能够立即处理5个请求中的每一个。相反，它会等待上一个任务（在bg线程上运行）完成，然后再为下一个任务提供服务 为了澄清这一点，我的配置试图模仿Node.js和Tornado等“单线程”异步服务器的线程体系结构 连接器：Servlets Tomcat7:异步Servlet不工作,servlets,tomcat7,Servlets,Tomcat7,我已经将Tomcat7配置为一个连接器线程，将作业发布到后台线程池中，后台线程异步完成请求。每个请求都有1秒的延迟。我的测试（JMeter）向上旋转5个线程并同时发出5个请求。我希望单连接器线程能够立即处理5个请求中的每一个。相反，它会等待上一个任务（在bg线程上运行）完成，然后再为下一个任务提供服务 为了澄清这一点，我的配置试图模仿Node.js和Tornado等“单线程”异步服务器的线程体系结构 连接器： @WebServlet(asyncSupported = true, value =
@WebServlet(asyncSupported = true, value = "/testasync", loadOnStartup = 1)
public class TestAsync extends HttpServlet {
private static final Logger LOG = Logger.getLogger(TestAsync.class.getName());
private static final long serialVersionUID = 1L;
private static final int NUM_WORKER_THREADS = 100;
private ExecutorService executor = null;
@Override
public void init() throws ServletException {
this.executor = Executors.newFixedThreadPool(NUM_WORKER_THREADS);
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
final AsyncContext ac = request.startAsync(); // obtain async context
ac.setTimeout(0); // test only, no timeout
LOG.info("received request on: " + Thread.currentThread().getId());
this.executor.execute(new Runnable() {
public void run() {
try {
LOG.info("processing request: "+ Thread.currentThread().getId());
Thread.sleep(5000);
LOG.info("processed request:"+ Thread.currentThread().getId());
ac.getResponse().getWriter().write("<h1>Request Processed</h1>");
ac.complete();
}
catch (Exception e) {
LOG.info("failed:" + e);
}
}
});
LOG.info("posted request on: " + Thread.currentThread().getId());
}
@WebServlet(asyncSupported = true, value = "/testasync", loadOnStartup = 1)
public class TestAsync extends HttpServlet {
private static final Logger LOG = Logger.getLogger(TestAsync.class.getName());
private static final long serialVersionUID = 1L;
private static final int NUM_WORKER_THREADS = 100;
private ExecutorService executor = null;
@Override
public void init() throws ServletException {
this.executor = Executors.newFixedThreadPool(NUM_WORKER_THREADS);
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
final AsyncContext ac = request.startAsync(); // obtain async context
ac.setTimeout(0); // test only, no timeout
LOG.info("received request on: " + Thread.currentThread().getId());
this.executor.execute(new Runnable() {
public void run() {
try {
LOG.info("processing request: "+ Thread.currentThread().getId());
Thread.sleep(5000);
LOG.info("processed request:"+ Thread.currentThread().getId());
ac.getResponse().getWriter().write("<h1>Request Processed</h1>");
ac.complete();
}
catch (Exception e) {
LOG.info("failed:" + e);
}
}
});
LOG.info("posted request on: " + Thread.currentThread().getId());
}
@WebServlet（asyncSupported=true，value=“/testasync”，loadOnStartup=1）
公共类TestAsync扩展了HttpServlet{
私有静态最终记录器LOG=Logger.getLogger（TestAsync.class.getName（））；
私有静态最终长serialVersionUID=1L；
私有静态final int NUM_WORKER_线程=100；
私有executor服务executor=null；
@凌驾
public void init（）引发ServletException{
this.executor=Executors.newFixedThreadPool（NUM\u WORKER\u THREADS）；
}
受保护的void doGet（HttpServletRequest请求，HttpServletResponse响应）抛出ServletException，IOException{
final AsyncContext ac=request.startAsync（）；//获取异步上下文
ac.setTimeout（0）；//仅测试，无超时
LOG.info（“在：+Thread.currentThread（）.getId（）上收到请求”）；
this.executor.execute（new Runnable（））{
公开募捐{
试一试{
LOG.info（“处理请求：+Thread.currentThread（）.getId（））；
睡眠（5000）；
LOG.info（“已处理的请求：+Thread.currentThread（）.getId（））；
ac.getResponse（）.getWriter（）.write（“已处理请求”）；
ac.完成（）；
}
捕获（例外e）{
日志信息（“失败：+e”）；
}
}
});
LOG.info（“在：+Thread.currentThread（）.getId（）上发布请求”）；
}
@WebServlet(asyncSupported = true, value = "/testasync", loadOnStartup = 1)
public class TestAsync extends HttpServlet {
private static final Logger LOG = Logger.getLogger(TestAsync.class.getName());
private static final long serialVersionUID = 1L;
private static final int NUM_WORKER_THREADS = 100;
private ExecutorService executor = null;
@Override
public void init() throws ServletException {
this.executor = Executors.newFixedThreadPool(NUM_WORKER_THREADS);
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
final AsyncContext ac = request.startAsync(); // obtain async context
ac.setTimeout(0); // test only, no timeout
LOG.info("received request on: " + Thread.currentThread().getId());
this.executor.execute(new Runnable() {
public void run() {
try {
LOG.info("processing request: "+ Thread.currentThread().getId());
Thread.sleep(5000);
LOG.info("processed request:"+ Thread.currentThread().getId());
ac.getResponse().getWriter().write("<h1>Request Processed</h1>");
ac.complete();
}
catch (Exception e) {
LOG.info("failed:" + e);
}
}
});
LOG.info("posted request on: " + Thread.currentThread().getId());
}
2013年9月17日下午12:26:25 TestAsync$1运行信息：已处理请求：31我认为这是由于Tomcat中使用了BIO连接器。这是Tomcat安装中的默认连接器。然后，通过池中的单个线程，您可以看到所描述的行为
如果将
maxThreads如果将
maxThreads如果你没有真正好的理由；没有理由在前面用一根线来限制自己。请参阅我提供的url。您应该使用所述的NIO连接器和执行器池
如果你没有真正好的理由；没有理由在前面用一根线来限制自己。请参阅我提供的url。我认为异步Servlet的目的是将连接器线程池与处理线程池解耦，这样，如果请求延迟很长，连接器线程就不会浪费（可以返回）。那么异步的好处是什么呢