Hello,
I notice there is similar problem just posted today. However, it doesn't seem to
have answer yet. Please let me try again...
My restlet application experiences uneven response time and for a while, the
requests would choked then a big load got processed. In order to isolate the
problem, I took away the logic inside the Resource. Now my Resource is as simple
as parsing a JSON payload then set the response to successfully accepted.
@Override
public void post(Representation entity) {
if (entity == null) {
this.getResponse().setStatus(Status.CLIENT_ERROR_BAD_REQUEST);
} else {
try {
Form form = new Form(entity);
String payloadText = form.getFirstValue(PAYLOAD);
if (StringUtils.hasText(payloadText)) {
JSONObject payload = new JSONObject(payloadText);
this.getResponse().setStatus(Status.SUCCESS_ACCEPTED);
} else {
this.getResponse().setStatus(Status.CLIENT_ERROR_BAD_REQUEST);
}
} catch (JSONException je) {
this.getResponse().setStatus(Status.CLIENT_ERROR_BAD_REQUEST);
} catch (Exception e) {
this.getResponse().setStatus(Status.SERVER_ERROR_SERVICE_UNAVAILABLE);
}
}
}
My client sends 10 post request per second evenly.
final ScheduledFuture<?> testHandle = scheduler.scheduleAtFixedRate(tester,
5000, 100, java.util.concurrent.TimeUnit.MILLISECONDS);
Periodically there were some requests taking very long. Here are some examples,
the number is in milliseconds.
A long request took 45008
A long request took 93003
A long request took 93001
A long request took 189002
A long request took 45001
....
The application is at java version "1.5.0_15", Restlet 1.0.9, Tomcat 6.0.16,
Windows XP dual core.
JAVA_OPTS=-server -showversion -Xms1g -Xmx1g -Xss512k -XX:+UseParallelGC
-XX:+UseParallelOldGC -XX:ParallelGCThreads=4 -Djava.net.preferIPV4Stack=true
-Dfile.encoding=UTF-8
I am not convinced GC is the reason. Because I have YourKit on the application,
I don't see that every time when the request chokes, the GC is running. Please
let me know what else I should looking for at YourKit.
Thank you very much.
