Bonjour Jeanfrancois,
Merci pour la reaction rapide.
Two things:
1) I do indeed call:
cometContext.setExpirationDelay(29000);
I do this with the intent to prevent browsers timing out the connection, or is there really no need for that. Should I not
use cometContext.setExpirationDelay() ?
2) There seems to be indeed some kind of a race condition. I wrote you before that the client re-opens the connection
ASAP. If I add the thread.sleep(1000) before the code that add's the CometHandler to the CometContext (on the server side,
when the connection is re-opened), then my error does not surface anymore, even not after 20 minutes!
public void doConnect(HttpServletRequest req, HttpServletResponse res) {
try {
Thread.sleep(1000);
res.setContentType("text/html;charset=ISO-8859-1");
GWTCometHandler cometHandler = new GWTCometHandler();
cometHandler.attach(res);
cometHandler.attachRequest(req);
cometContext.addCometHandler(cometHandler); //Executing this operation tells Grizzly to suspend the underlying connection, and avoids committing the response until the handler will be removed from the context
}
catch (Exception e) {
log("Exception in doConnect: " + e);
}
}
Hope you can do something with this.
Date: Mon, 06 Oct 2008 11:54:35 -0400
From: Jeanfrancois Arcand <Jeanfrancois.Arcand_at_Sun.COM>
Content-type: text/plain; format=flowed; charset=ISO-8859-1
Subject: getWriter() has already been called for this response
Salut,
Aart de Vries wrote:
> I'm on:
> - OpenSuse 11.0
> - java 1.6.0_07
> - GlassfishV3-prelude-b26 (with integrated Grizzly 1.8.6)
> - GWT 1.5.2 building upon example from
> http://www.javascriptr.com/2008/05/28/gwt-grizzly-comet/
> - dual core T8400 at 3GHz.
>
> In essence I want to achieve long polling. My evaluation code writes a
> string message after a delay of 5 seconds
> using the following code:
> public void onEvent(CometEvent cometEvent) throws IOException {
> Message msg = (Message) cometEvent.attachment();
> try {
> String encoded =
> RPC.encodeResponseForSuccess(CometServiceImpl.class.getMethod("comet"),
> msg);
> writeResponse(req, res, encoded);
> cometContext.resumeCometHandler(this);
> }
> catch (Exception e) {
> log("Exception in GWTCometHandler.onEvent: " + e);
> e.printStackTrace();
> }
> }
> From the browser client, I keep calling this code, by re-opening a
> connection after having received an answer.
>
> The code works, and glassfish is not blocking IO anymore even if I hit
> the server with 10 browser instances. Great work
> guys. But so now and then I get the error message below (even when I hit
> my server form a single client), which makes
> me believe that, although I only have a single notify() every 5 seconds,
> sometimes more than once my onEvent gets called by
> the Comet framework. This happens at irregular intervals, sometimes
> after 30 seconds, sometimes after several minutes.
Have you, by any chance, changed the default timeout value when creating
the CometContext:
cometContext.setExpirationDelay(..); [1]
Based on the above, it seems there is a small thread race between the
invocation of onEvent() and onInterrupt(). Can you try to synchronized
the onEvent method to see if that help?
>
> PS. I would be happy to evaluate Grizzly 1.8.6.1 to see if this issue is
> already out of the way. Could somebody refer to some
> documentation that will allow me to run 1.8.6.1 from within GlassfishV3,
That's not simple. Mainly, you need to do something like:
% unzip grizzly-comet-1.8.6.1.jar
% jar uvf grizzly-optionals.jar com
A+
-- Jeanfrancois
> since the obvious attempt of bluntly removing it's
> grizzly-modules.jar and grizzly-optionals.jar files and adding in the
> same directory the 1.8.6.1 jars doesn't work.
>
> java.lang.IllegalStateException: PWC3990: getWriter() has already been
> called for this response
> at
> org.apache.catalina.connector.Response.getOutputStream(Response.java:685)
> at
> org.apache.catalina.connector.ResponseFacade.getOutputStream(ResponseFacade.java:213)
> at
> com.google.gwt.user.server.rpc.RPCServletUtils.writeResponse(RPCServletUtils.java:234)
> at
> com.google.gwt.user.server.rpc.RemoteServiceServlet.writeResponse(RemoteServiceServlet.java:379)
> at
> com.google.gwt.user.server.rpc.RemoteServiceServlet.doPost(RemoteServiceServlet.java:94)
> at javax.servlet.http.HttpServlet.service(HttpServlet.java:754)
> at javax.servlet.http.HttpServlet.service(HttpServlet.java:847)
> at
> org.apache.catalina.core.ApplicationFilterChain.servletService(ApplicationFilterChain.java:431)
> at
> org.apache.catalina.core.StandardWrapperValve.preInvoke(StandardWrapperValve.java:462)
> at
> org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:139)
> at
> org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:186)
> at
> org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:719)
> at
> org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:657)
> at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:96)
> at
> com.sun.enterprise.web.PESessionLockingStandardPipeline.invoke(PESessionLockingStandardPipeline.java:98)
> at
> org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:187)
> at
> org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:719)
> at
> org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:657)
> at
> org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:651)
> at
> org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:1030)
> at
> org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:142)
> at
> org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:719)
> at
> org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:657)
> at
> org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:651)
> at
> org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:1030)
> at
> org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:307)
> at
> org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:226)
> at
> com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:180)
> at
> com.sun.grizzly.http.DefaultProcessorTask.invokeAdapter(DefaultProcessorTask.java:625)
> at
> com.sun.grizzly.comet.CometEngine.executeServlet(CometEngine.java:564)
> at com.sun.grizzly.comet.CometEngine.handle(CometEngine.java:318)
> at
> com.sun.grizzly.comet.CometAsyncFilter.doFilter(CometAsyncFilter.java:84)
> at
> com.sun.grizzly.arp.DefaultAsyncExecutor.invokeFilters(DefaultAsyncExecutor.java:130)
> at
> com.sun.grizzly.arp.DefaultAsyncExecutor.interrupt(DefaultAsyncExecutor.java:109)
> at
> com.sun.grizzly.arp.AsyncProcessorTask.doTask(AsyncProcessorTask.java:88)
> at com.sun.grizzly.http.TaskBase.call(TaskBase.java:359)
> at
> com.sun.grizzly.util.WorkerThreadImpl.processTask(WorkerThreadImpl.java:325)
> at
> com.sun.grizzly.util.WorkerThreadImpl.run(WorkerThreadImpl.java:184)
>
>
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