Why does select() consume so much CPU time in my program?

Question

I have several Java applications that use MINA, and all of them use 20 MINA threads. One application serves around 10,000 concurrent connections, that are usually idle but r

Answer 1

Firstly, it's good that both applications have the same issue; it probably indicates that the issue is with either the JVM or the OS and not your application :-)

As jzd mentioned, nio.select() has had issues. The multiplication of {various versions of Java} x {various platforms, kernel versions} makes it seem like an all-over-the-place issue. I hope one of these works for you :

• If you are on Linux, try the 2.6 kernel just in case you are on 2.4

  , assuming the bug is akin to : http://bugs.sun.com/view_bug.do?bug_id=6670302

• Use an older version of the JRE / JDK, not the latest version!

  , i.e., go back to JRE 6 / JDK 6 instead of 7.

Try

• {older version of JRE (6), older version of Linux kernel} or
• {newer version of JRE (7), newer version of Linux kernel}

instead of mixing them up as in {older, newer} or {newer, older}.