Am Montag, den 17.07.2006, 03:44 +0200 schrieb Zsombor: > 2006. 07. 14, péntek keltezéssel 16.08-kor Joachim Draeger ezt írta: > > I was looking for the maximal number of threads Java is able to run I > > found the answer that it is only limited by memory... > > I always try to challenge propositions. Is it even a problem to have a > > sleeping thread per connection? > > > > Several years ago, several jobs far away, I had some experience with the > non-blocking socket handling vs one-thread-per-connection strategy > issue. Please consider the followings to see my experiences in context: > a, that was a Linux machine with a kernel from the 2.4 series (so every > java thread handled as a process by the kernel) > b, the best JVM of that time was the IBM 1.3.1. (java.nio was only a > dream, and a weak promise) > c, the application was a simple chat server, minimal input, a lots of > output. > > With the old, one-thread-per-connection strategy we had: > a, after 600-700 connection the system becamed very unstable and > irresponsible, the load was between 10 and 20, the VM had grown more > then 512 MB in the RAM. > b, after ~800 connection the VM was unable to create any additional > threads, and silently died. > > After I rewrote in a non-blocking fashion the same machine and VM could > serve 1200-1300 connections, in a much more responsible manner. > > I know, that with kernels from the 2.6 series able to handle much more > threads, but every context switch has a cost penalty, and if you have > hundreds or thousands of threads, it can (and will) cause some pain. > > BR, > Zsombor
BTW, we want switch to MINA for connectionhandling. So this should be no problem then.. bye Norman
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