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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