[ http://issues.apache.org/jira/browse/DIRMINA-221?page=all ]
Emmanuel Lecharny resolved DIRMINA-221:
---------------------------------------
Resolution: Invalid
That's very true ... I should have been tired yesturday :)
> Long wait interval between requests with a single threaded client
> -----------------------------------------------------------------
>
> Key: DIRMINA-221
> URL: http://issues.apache.org/jira/browse/DIRMINA-221
> Project: Directory MINA
> Type: Improvement
> Reporter: Emmanuel Lecharny
> Priority: Critical
> Attachments: test-server.tgz
>
> Hi MINA band,
> we are currently experiencing a very strange behavior in MINA. While doing
> performances tests of ADS? we found that we cannot go upper than 25 search
> requests per second. We stripped the server from its backend, and eventually,
> Alex wrote a single client/server program unsing MINA to isolate the pb.
> Vasically, we have a client which continuously send requests, and get a
> result from a very simplified server. If the client has only one thread
> running, there is a wall we hit ate around 25 req/s. If we use more than one
> thread, suddenly this wall go up to NbThreads*25 req/s (ie, with 4 threads
> requesting, we reach 100 req/s, with 10, 250 req/s, ... with 100 threads, we
> have 1500 req/s).
> After having put some traces into MINA, here what I found in BlockingQueue :
> those two methods seems to be connected. When you call notifyAdd, then the
> method waitForNewItem() wait stops. We are waiting for an average of 40ms for
> each request in the waitForNewItem() method, ad I don't know which kind of
> processing or synchronization generate those 40ms wait.
> ...
> private void notifyAdded()
> {
> if( waiters > 0 )
> notify();
> }
> ...
> ...
> public synchronized void waitForNewItem() throws InterruptedException
> {
> waiters++;
> try
> {
> while( super.isEmpty() )
> {
> wait();
> ...
> Here is a sample of time wait we have in the fetchBuffer() method, which call
> the waitForNewItem() method (time is in ms) :
> ...
> Waited : 42
> fetchBuffer : 42
> Waited : 0
> fetchBuffer : 0
> Waited : 1
> fetchBuffer : 1
> Waited : 39
> fetchBuffer : 39
> Waited : 0
> fetchBuffer : 0
> Waited : 1
> fetchBuffer : 1
> Waited : 39
> fetchBuffer : 39
> Waited : 0
> fetchBuffer : 0
> Waited : 1
> fetchBuffer : 1
> Waited : 39
> fetchBuffer : 39
> Waited : 0
> fetchBuffer : 0
> Waited : 1
> ...
> I know that the wait I get the delay is not very optimal
> (System.currentTimeMillis()), but 40 ms is *very* long.
> At this point, Alex and me are clueless. We have not enough understanding on
> the Mina internals to explian and fix this problem - if it's a problem -, or
> to configure MINA to avoid this kind of behavior.
> If any of you could help us, this will be *very* appreciated, as the whole
> LDAP server perfomance relies on MINA.
> Thanks !
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