Please check upstream if this combination causes the problem:
AMD architecture
+
glibc glibc-2.5-49.el5_5.7 update of late October
+
java-1.6.0-sun-compat-1.6.0.22-3.sl5.jpp.i586
+
absence of 32 bit version of nss-mdns
This may be causing headaches for many sysadmins.
Cheers!
On 3.11.10, Steve White wrote:
> For the record, here's the solution.
>
> yum install nss-mdns
>
> Now, this is an x86_64 machine, and the 64-bit version of the library
> was already installed, but not the 32 bit version. The installation of
> the 32 bit version was the fix.
>
> Evidently JVM is running in 32 bit.
>
> As to why the 32 bit library was not installed, I don't know.
> The yum.log shows only the 64 bit version being installed, until I installed
> the 32 bit one by hand.
>
> Can anybody shed more light on this?
>
> Cheers!
>
> On 2.11.10, Steve White wrote:
> > Hi again,
> >
> > I just came across a huge clue. A friend had me look again at the java.net
> > properties. This one makes the test program work:
> > -Djava.net.preferIPv4Stack=true
> >
> > Now, as to why suddenly Java was preferring the IPv6 stack, I have no idea.
> >
> > On 2.11.10, Steve White wrote:
> > > Hi,
> > >
> > > A Java networking problem has arisen very recently on one of our servers,
> > > an Opeteron with Scientific Linux 5.5, running the distro Java without
> > > problems--until a week or so ago.
> > >
> > > The effect is that all Java apps have become unable to do DNS host name
> > > resolution, and throw an UnknownHostException. However nothing seems
> > > otherwise amiss with networking on this machine. All non-Java programs
> > > resolve outside host names fine.
> > >
> > > I wrote a small test program, attached. It works fine on other machines
> > > here. Fails on the server, with an IP address. But if I give it a valid
> > > IP number, or the name of the server itself, it succeeds.
> > >
> > > I have done security updates fairly regularly; this may have something to
> > > do with the problem, but I really don't know for sure.
> > >
> > > Also tried:
> > >
> > > * Cut the hosts file down to the bare minimum, and also the resolv.conf
> > > file and re-started networking. No improvement.
> > >
> > > * Logged in as various users. All show the same problem.
> > >
> > > * Cut down and exported all related environment variables to bare minimum
> > > (JAVA_HOME, PATH, *LIBRARY_PATH, etc),
> > > No effect.
> > >
> > > * Reversed the updates from last week, and re-booted with the
> > > previous kernel. No improvement.
> > >
> > > * Fiddled with various Java system properties, as in
> > >
> > > http://download.oracle.com/javase/6/docs/technotes/guides/net/properties.html
> > > Nothing seemed to help.
> > >
> > > * Installed a Java 1.5, built the test program with it, ran the test
> > > program
> > > under that. It failed just like the distro version.
> > >
> > > Any ideas?
> > >
> > > =========================================================
> > > To run the attached test
> > > javac nettest.java
> > > java nettest <hostname> <optional-port-number>
> > >
> > > | - - - - - - - - - - - - - - - - - - - - - - - -
> > > -
> > > import java.net.Socket;
> > >
> > > public class
> > > nettest
> > > {
> > > public static void
> > > main( String [] a )
> > > {
> > > if( a.length > 0 )
> > > {
> > > String host = a[0];
> > > int port = 80;
> > > if( a.length > 1 )
> > > {
> > > port = Integer.parseInt( a[1] );
> > > }
> > > try
> > > {
> > > Socket si = new Socket( host, port );
> > > System.out.println( "Success connecting to "
> > > + host );
> > > }
> > > catch( Exception e )
> > > {
> > > System.err.println( e.toString() );
> > > e.printStackTrace();
> > > }
> > > }
> > > else
> > > {
> > > System.err.println( "please provide host string" );
> > > }
> > > }
> > > }
> >
>
> --
> | - - - - - - - - - - - - - - - - - - - - - - - - -
> | Steve White +49(331)7499-202
> | E-Science Zi. 27 Villa Turbulenz
> | - - - - - - - - - - - - - - - - - - - - - - - - -
> | Astrophysikalisches Institut Potsdam (AIP)
> | An der Sternwarte 16, D-14482 Potsdam
> |
> | Vorstand: Prof. Dr. Matthias Steinmetz, Peter A. Stolz
> |
> | Stiftung privaten Rechts, Stiftungsverzeichnis Brandenburg: III/7-71-026
> | - - - - - - - - - - - - - - - - - - - - - - - - -
--
| - - - - - - - - - - - - - - - - - - - - - - - - -
| Steve White +49(331)7499-202
| E-Science Zi. 27 Villa Turbulenz
| - - - - - - - - - - - - - - - - - - - - - - - - -
| Astrophysikalisches Institut Potsdam (AIP)
| An der Sternwarte 16, D-14482 Potsdam
|
| Vorstand: Prof. Dr. Matthias Steinmetz, Peter A. Stolz
|
| Stiftung privaten Rechts, Stiftungsverzeichnis Brandenburg: III/7-71-026
| - - - - - - - - - - - - - - - - - - - - - - - - -
