Name: krC82822 Date: 03/20/2001
java version "1.3.1-beta"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.3.1-beta-b15)
Classic VM (build 1.3.1-beta-b15, green threads, nojit)
I'm using a new Red Hat Linux 7.0 server installation. I needed to upgrade from
Glibc version 2.1.92 to version 2.2 in order to get any Java VM to work.
[john@ppro vmark2.1.2]$ cat /etc/redhat-release
Red Hat Linux release 7.0 (Guinness)
[john@ppro vmark2.1.2]$ uname -a
Linux ppro.sf.volano.net 2.2.16-22smp #1 SMP Tue Aug 22 16:39:21 EDT 2000 i686
unknown
[john@ppro vmark2.1.2]$ rpm -q glibc
glibc-2.2-12
I upgraded Glibc from here:
http://www.redhat.com/support/errata/RHSA-2001-001.html
The problem is that the VM goes into a hard run (using up all available CPU)
when it reaches 1,018 concurrent socket connections. The problem is easily
reproducible when I use our VolanoMark network scalability test to try to
establish 2,000 concurrent connections over the network from another machine.
The server side under test is started with:
/usr/java/jdk1.3.1/bin/java -classic -showversion -Xms8m -Xmx256m -Xss32k
COM.volano.Main
The problem occurs with or without the stack size option ("-Xss32k").
The client side is started on another machine (running Solaris 8 Intel) with:
$HOME/j2sdk1_3_0RC/bin/java -server -showversion -Xms64m -Xmx256m -Xss64k
COM.volano.Mark -host ppro2 -rooms 100
The problem does not occur with the following Blackdown J2SDK 1.3.0-FCS release:
java version "1.3.0"
Java(TM) 2 Runtime Environment, Standard Edition (build Blackdown-1.3.0-FCS)
Classic VM (build Blackdown-1.3.0-FCS, green threads, nojit)
In fact, the Blackdown 1.3.0-FCS release can easily handle up to 5,000 active
concurrent socket connections over the network.
I was unable to test the HotSpot VM since it fails with:
[john@ppro john]$ /usr/java/jdk1.3.1/bin/java -version
/usr/java/jdk1.3.1/bin/i386/native_threads/java: error while loading shared
libraries: libstdc++-libc6.1-1.so.2: cannot load shared object file: No such
file or directory
In my earlier testing, the HotSpot Server VM failed at 440 concurrent
connections because of limits on the number of Linux native threads.
(Review ID: 119091)
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