Re: High latency in Mina ?

Csaba Endre Simon a écrit :

> Hi Emmanuel,

Hi Csaba,

> > 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 published results are on Linux? What kernel are you using?

It's on MacOSx (intel). It's BSD based. I have also tested it on Fedora 
Core 5, and on a Suse (2.6.18.2-34-xen #1 SMP, 8 CPU, 64 bits)

> I also made some tests with MINA and on the *same* hardware with
> *different* Operating Systems I got different results. Tested on Linux
> kernel 2.4, Linux kernel 2.6 and Solaris. My server responds with a
> lot of small packet to the client request. This approach on kernel 2.6
> seems that is 4.5X slower than on kernel 2.4 or Solaris. Traced with
> strace it seems that the kernels is descheduling  my server
> application: the same sized packet sometimes takes a *lot* more time
> to send (time spent in system call "write") then normal.
>
> This 4.5X seems like a constant :-) Does not mater if the application
> is in C or C++ or Java using MINA. The only way to overcome the 2.6
> kernel bad behavior is to buffer all the small packets and send it
> onces. 

The packet size is not big in my case (no more than 1 kb), and they are 
sent in one shot (no scattering). The received packets are even smaller 
(less than 100 bytes).

Thanks,
Emmanuel