[hardy] ia32 build of java fails to resolve dns names in some cases

[Jason Felice]

Binary package hint: ia32-sun-java5-bin

jfelice@flarp64:/tmp$ lsb_release -rd
Description: Ubuntu 8.04
Release: 8.04
jfelice@flarp64:/tmp$ uname -a
Linux flarp64 2.6.24-16-generic #1 SMP Thu Apr 10 12:47:45 UTC 2008 x86_64 GNU/Linux
jfelice@flarp64:/tmp$ cat foo.java
public class foo {
    public static void main(String[] argv) {
        try {
            new java.net.Socket("www.topcoder.com",5001);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}
jfelice@flarp64:/tmp$ javac foo.java
jfelice@flarp64:/tmp$ /usr/lib/jvm/java-1.5.0-sun/bin/java foo
jfelice@flarp64:/tmp$ /usr/lib/jvm/ia32-java-1.5.0-sun/bin/java foo
java.net.UnknownHostException: www.topcoder.com
        at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:177)
        at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366)
        at java.net.Socket.connect(Socket.java:520)
        at java.net.Socket.connect(Socket.java:470)
        at java.net.Socket.<init>(Socket.java:367)
        at java.net.Socket.<init>(Socket.java:180)
        at foo.main(foo.java:4)
jfelice@flarp64:/tmp$

Note that this happens for other people as well:

http://forums.topcoder.com/?module=Thread&threadID=611945&start=0&mc=17#970318

(I'm "eraserhd")

[Jason Felice (jason-m-felice)]

I forgot to mention that adding 'www.topcoder.com' to /etc/hosts allows the 32-bit java to work.

Also, here is a screenshot showing some diagnostics about a locking issue that occurs just before the problem in another circumstance. I don't believe it is relevant, but just in case:

http://eraserhead.net/arena-problem.png

[Dan Everton (dan-iocaine)]

This also seems to affect the ia32 version of Java 6 too.

[Arkaaito (alstisgi)]

Me three!

Sorry for this, my initial search failed to turn up your thread: http://forums.topcoder.com/?module=Thread&threadID=608713&start=0&mc=5#972557

Reproed on Debian x64. Some other details are in the thread - feel free also to e-mail me if I can be of assistance in pinning the problem down further.

[Jason Felice (jason-m-felice)]

I've found a better work around that suggests this is a problem with ia32-libs.

If you edit /etc/nsswitch.conf and place 'dns' before the 'mdns4_minimal' on the 'hosts' line, it will work.

I can't figure out why, though. In C, gethostbyname() works in both 32 and 64 bit. I don't know how to track down what Java does to resolve names.

[Jason Felice (jason-m-felice)]

OK, it looks like this is a duplicate of a known bug.

Solution: apt-get install lib32nss-mdns

I'm marking as dup.

[Lex Ross (lross)]

Installing lib32nss-mdns did not help me with both Hardy and Intrepid 8.10 RC/64-bit. Neither did putting the site into /etc/hosts. Sun's 32-bit javaws fails to connect to server, period. Open java provided by default logs into server but does not work with application. I am forced to reboot into 32-bit Gutsy whenever I need to use Java web start. Any ideas? And when 64-bit version of Sun Java Web Start is going to be released? I think it is up to the community now.