Concurrent Problem of CXF on tomcat?

[xuhb]

Hi:
    I build a simple proxy with cxf(2.4.3) & camel(2.8.1) on tomcat, and trying 
to test the performance with HP LoadRunner;
    the proxy program is build with pay-load model of camel-cxf;

    If the concurrent client is only  1, there is nothing wrong, the throughput 
capacity is very stable (about 150 hits/second)
    If I increasei concurrent clients (etc to 40) ,  the throughput capacity 
doesn't increased, but drop down to a very slow number; (the hits/second is 
only serval number);

    when concurrent clients is 40, at first the speed of cxf proxy is very 
fast, but after a serveral seconds there are serveral 
"java.net.SocketException: Unexpected end of file from server" occurs , and 
then the speed of proxy will drop to very slow;

     Tthe camel-cxf will share same cxf-client in multi threads ( I have ask a 
question of CXF client concurrents, accoding to CXF FAQ , it is thread safe in 
my test usage), 
and is there other issues cause such a concurrent problem ?

    Thanks for any suggestion;