Hey Emmanuel, I'm not sure I understand your point or if there is a problem. :) I would say that it is fine and even expected to find that most of your CPU time is spent in MINA (or I/O work) if your application is super fast (e.g. does not do much) and all you do is send and receive data to the server.
However, if you see that MINA is slowing you down then the story is different. But I don't see that from your stats. Or may be I'm missing something. :) Regards, -- Gato -----Original Message----- From: Emmanuel Lecharny [mailto:[EMAIL PROTECTED] Sent: Friday, March 30, 2007 10:26 AM To: dev@mina.apache.org Subject: High latency in Mina ? Hi guys, I'm currently doing some performance tests on Apache Directory Server, and I'm a little bit puzzled but some of the results I get. First of all, we are using MINA-1.0.1, with different JVM (JRockit, IBM, Sun) on different platforms (Linux, Mac OSx). The tests is quite simple : I have some Ldap clients (a very simple injector which binds, launch N threads and for each threads launch P searches requests). I cannot go farther than 2000 requests/s... I have added some timer in the code, and I have been very surprised to see that ADS itself does not cost that much. In fact, we have 3 importants parts : 1) decode a message 2) handle the message 3) encode the response The sum of those three operations just cost less than 10 percents of the global cost for the operation to be fullfilled. (so an operation cost around 0,5 ms, and only 10 micro seconds into ADS). MINA cost 0,490 ms alone. To be sure, I added a loggingFilter, and I computed the duration of a message processing (I added some info in messageReceived and messageSent : as a Ldap message may be sent in more than one piece, and so is the answer, I consider the last time for a message sent compared to the last time a message has been received, so I compute the date when thelast bit has been sent minus the date when the first bit has been received). Here is what I get (all the number are in nanoseconds, and they have been computed using an accumulator, printed every 1000 messages) : Delta write = 4925 Encode cost : 944 Delta write = 6613 Decode cost : 1656 Search cost : 44239 Delta write = 2263 Encode cost : 1062 Delta write = 2893 Delta write = 5544 Mina costs 872 051 (including all the above, 70 138 ns). Ok, those number are just given as an example, but what we see is that MINA represent 90% of the total cost. I have done this test on my desktop, with a client on my desktop, or with a client on another desktop (100 Mb/s ethernet). The volume of transfered data is not enormous, it's around 1kb per message, so for 2000 messages per second, it's around 16 Mb/s, far under the maximum network capacity. The sockets are never closed, and no new threads are being created. Ok, I have reached my limit, I don't know MINA enough to go farther ... Any advice? Any clue? Thanks very much for any help ! PS: the code is of course available on svn.apache.org/repos/asf/directory/apacheds/trunk -- Cordialement, Emmanuel Lécharny www.iktek.com
