Asynchronous context not synchronized

Question

I am trying to use the asynchronous context timeout function. But the behavior is very choppy. Sometimes a timeout occurs, and many times it does not. I embed my code here.

@WebServlet(name = "TestServlet", urlPatterns = {"/test"},asyncSupported = true) public class TestServlet extends HttpServlet{ private static final long serialVersionUID = 1L; private static PriorityBlockingQueue<Runnable> pq = new PriorityBlockingQueue<Runnable>(1000); private static ThreadPoolExecutor threadPoolExecutor = new ThreadPoolExecutor(1,1,10, TimeUnit.SECONDS,pq); public void service(final ServletRequest servletRequest, final ServletResponse response) throws ServletException, IOException { TestListener listener = new TestListener(); final AsyncContext asyncContext = servletRequest.startAsync(); asyncContext.addListener(listener); asyncContext.setTimeout(100); Handler handler = new Handler(asyncContext); threadPoolExecutor.execute(handler); } } 

The following is a list of listeners and a handler code.

 public class TestListener implements AsyncListener { public void onComplete(AsyncEvent event) throws IOException { System.out.println("Event completed"); } public void onError(AsyncEvent event) throws IOException { event.getAsyncContext().complete(); } public void onStartAsync(AsyncEvent event) throws IOException { // TODO Auto-generated method stub } public void onTimeout(AsyncEvent event){ System.out.println("Timeout "); event.getAsyncContext().complete(); } } public class Handler implements Runnable { private AsyncContext asyncContext; public Handler(AsyncContext asyncContext){ this.asyncContext = asyncContext; } public void run(){ try { long currtime = System.currentTimeMillis(); Thread.sleep(500); System.out.println("slept for " + (System.currentTimeMillis() - currtime)); } catch (InterruptedException e) { System.out.println("Error in thread "); } try{ if(asyncContext != null){ System.out.println("Completing async context " + " timeout is " + asyncContext.getTimeout()); asyncContext.complete(); } }catch (Exception e){ System.out.println("Exception in completing async context "); } } } 

And the output is intermittent. Including here -

 [ ops@root combinedlogs]$ time curl "http://localhost:9001/mockresponse/test" real 0m0.506s user 0m0.001s sys 0m0.003s [ ops@root combinedlogs]$ time curl "http://localhost:9001/mockresponse/test" real 0m0.159s user 0m0.001s sys 0m0.003s 

Catalina logs -

 slept for 500 Completing async context timeout is 100 Event completed Timeout Event completed slept for 500 Exception in completing async context 

I do not understand why this is happening. Please help! Thank you for your time.

PS: tomcat version - 7.0.37

Answer 1

Try increasing the timeout and waiting interval by more than 1 second.
For example: try the waiting interval of 2 seconds and sleep for 5 seconds.
Perhaps the servlet container does not detect timeouts of less than 1 second.
There were several errors (slightly) related to such subsecond timeouts earlier in tomcat, for example this one .
I understand that you are using a later version of tomcat than mentioned in this error, but still worth a try.