dev@grizzly.java.net

Re: memory usage with asyncfilter

From: Oleksiy Stashok <Oleksiy.Stashok_at_Sun.COM>
Date: Sat, 31 Oct 2009 00:26:48 +0100

Hi Rama,

IMO I've found what causes the higher memory consumption, when
AsyncFilter is enabled.

Here are my findings, which will help to understand the issue and fix
I'm proposing...

Basically there is no leak, but because of specific, how we run
AsyncProcessorTask - we create and cache much more ProcessorTasks
objects, than for regular usecause without AsyncFilters.
By specific, I mean approach how we're running AsyncProcessorTask in
DefaultAsyncHandler.handle() method. Each AsyncProcessorTask is run in
a *new* worker thread (which seems redundant for me, because the
current thread is a worker thread). The situation is following...
Assume we have thread pool with max 5 threads and 50 HTTP requests
come simultaneously. We enqueue those requests tasks in a worker
thread queue.

1) Thread-Pool queue:
50 Request tasks

Now first thread picks up first request task, which polls
ProcessorTask cache, which is empty, so it creates new ProcessorTask
and executes it using AsyncProcessorTask in a new worker thread. So
basically we processed so called request task, but added new
AsyncProcessorTask on a worker thread queue.

2) Thread-Pool queue:
49 Request tasks
1 AsyncProcessorTask

The same situation happens with the 2nd request task, again we create
new ProcessorTask and execute it using AsyncProcessorTask in a new
worker thread. So basically enqueue one more AsyncProcessorTask.

3) Thread-Pool queue:
48 Request tasks
2 AsyncProcessorTask

So finally we will come to up to *50* ProcessorTasks created to
process 50 requests, which then will be stored in ProcessorTask cache.

Notice, that in normal usecase, without AsyncFilters, we will have
only *5* ProcessorTasks in cache, one per each thread.

So the easiest solution I can propose is to run AsyncProcessorTasks in
the current worker thread (diff is attached).

Jeanfrancois, can I ask you to review it?

Thanks.

WBR,
Alexey.






On Oct 30, 2009, at 12:30 , rama.rama_at_tiscali.it wrote:

> Ok back :D
>
> let's be back to memory usage issue.
>
>
>
> at the end fo the
> mail you can found the test that i have used to found this issue.
>
> let
> me explain how and why i think that there is something of strange.
>
>
> 1)
> i'll start a gws, with a static adapter that say "yo"
> 2) this gws,
> after a 2500ms, will do a GC :)
> 3) after a small warmup, a couple of
> secs, this is the memory usage
> RE 0 MU 1788240
> this means that i
> haven't do any request and that 1788240 is the minimal memory usage of
> this example.
>
>
> now, let's start AB benchmark.
>
> ab -c 200 -n 20000
> http://192.168.2.143:8080/
>
> wait a bit (to have some GC issued) and
> copy again the memory usage
> RE 20001 MU 6038432 --> after the AB (why
> there s 1 more request?? maybe my code is stupid)
> RE 20001 MU 4419504 --
>> 1 min later :)
>
>
>
> let's start the 1st test with a AsyncFilter.
> The
> asyncfilter, added to this gws, is configured as follow. If the uri
> contains "rama" it will just schedule the request to be issued 10 ms
> later.
> if not, the request will simply proceed.
>
> Let's start it! and
> allow a little warmup :)
> RE 0 MU 1786376
> pretty much the same of
> before, so we are ready for the test!
>
>
> now, let's start AB benchmark.
>
>
> ab -c 200 -n 20000 http://192.168.2.143:8080/ --> as you can notice,
> there isn't any "rama" on the uri, so asyncfilter, will just pass the
> request to be executed later :)
>
> and we got
> RE 20076 MU 62715680 -->
> after the AB (why there is 76 more request?? maybe ab is stupid?!? :))
>
> RE 20076 MU 56168440 --> 3 mins later (sorry i have a call hehehe)
>
>
> In
> any case, you can see the enormous memory usage while using
> asyncfilter
> (and without even suspending a request!!)
>
>
> So, just with the 1st test,
> i am a bit worried about that..maybe my fault? if so, please, check
> the
> example and let me know where is the error (i have copy the example
> here http://weblogs.java.
> net/blog/jfarcand/archive/2008/07/extending_the_g.html btw)
>
>
> let's
> start the 2nd test case.
> Same code of above.
>
> ab -c 200 -n 20000 http:
> //192.168.2.143:8080/rama (so suspend is on)
>
> and we got
> RE 20005 MU
> 68343376 --> after AB (05?? what the hell!!)
> RE 20005 MU 68293528 --> 1
> mins later
>
> Any help is appreciated :)
>
> and here is the test code!
>
>
> ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
>
> package test;
>
> import com.eg.euler.ipc.http.newHttp.EulerAsyncAdapter;
>
> import com.sun.grizzly.arp.AsyncExecutor;
> import com.sun.grizzly.arp.
> AsyncFilter;
> import com.sun.grizzly.http.embed.GrizzlyWebServer;
> import
> com.sun.grizzly.tcp.http11.GrizzlyAdapter;
> import com.sun.grizzly.tcp.
> http11.GrizzlyRequest;
> import com.sun.grizzly.tcp.http11.
> GrizzlyResponse;
>
> import java.io.IOException;
> import java.util.
> concurrent.Callable;
> import java.util.concurrent.
> ScheduledThreadPoolExecutor;
> import java.util.concurrent.TimeUnit;
>
> import java.util.concurrent.atomic.AtomicInteger;
>
> /**
> * Created by
> IntelliJ IDEA.
> * User: Rama
> * Date: 30-ott-2009
> * Time: 11.49.46
> */
>
> public class DemoWebServer {
>
> static final AtomicInteger req = new
> AtomicInteger();
> public static void main(String args[]){
>
> GrizzlyWebServer test = new GrizzlyWebServer();
> test.
> addGrizzlyAdapter(new MyGrizzlyAdapter(),new String[]{"/"});
>
> test.addAsyncFilter(new MyAsyncFilter());
> test.
> getSelectorThread().setDisplayConfiguration(true);
> try {
>
> test.start();
> } catch (IOException e){
>
> e.printStackTrace(); //To change body of catch statement
> use File | Settings | File Templates.
> }
> while
> (true) {
>
> int reqn = req.get();
> System.out.
> println("RE "+reqn+" MU "+(Runtime.getRuntime().totalMemory() -
> Runtime.
> getRuntime().freeMemory()));
> try {
> Thread.
> sleep(2500);
> System.gc();System.gc();System.gc();
>
> } catch (Exception e) {
>
> }
>
>
> }
> }
>
>
> static class MyGrizzlyAdapter extends
> GrizzlyAdapter {
> public void service(GrizzlyRequest
> grizzlyRequest, GrizzlyResponse grizzlyResponse) {
> try {
>
> grizzlyResponse.getWriter().print("Great!");
>
> req.incrementAndGet();
> } catch (IOException
> e) {
>
> }
> }
> }
>
> static class MyAsyncFilter
> implements AsyncFilter {
> private final
> ScheduledThreadPoolExecutor scheduler =
>
> new ScheduledThreadPoolExecutor(1);
>
> public boolean doFilter
> (final AsyncExecutor asyncExecutor) {
> String url =
> asyncExecutor.getProcessorTask().getRequestURI();
>
>
> //if
> req url is rama, then delay the request
> if (url.contains
> ("rama")) {
> scheduler.schedule(new Callable() {
>
> public Object call() throws Exception {
>
> asyncExecutor.execute();
>
> asyncExecutor.postExecute();
>
> return null;
> }
>
> }, 10, TimeUnit.MILLISECONDS);
> return
> false;
> }
>
> //if not, let them pass :)
>
> try {
> asyncExecutor.execute();
>
> asyncExecutor.postExecute();
> } catch (Exception e) {
>
>
> }
>
> return false;
> }
> }
>
> }
>
>
>
>
> ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
>
>
>
>
>
>
>
>
> Passa a Tiscali Tutto Incluso Light: telefono + adsl 8 Mb senza
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