FULL PRODUCT VERSION :
java version "1.8.0_45"
Java(TM) SE Runtime Environment (build 1.8.0_45-b14)
Java HotSpot(TM) 64-Bit Server VM (build 25.45-b02, mixed mode)


ADDITIONAL OS VERSION INFORMATION :
Linux myhost.jp 2.6.32-358.18.1.el6.x86_64 #1 SMP Wed Aug 28 17:19:38 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux

EXTRA RELEVANT SYSTEM CONFIGURATION :
VPN server on Sakura JP provider

A DESCRIPTION OF THE PROBLEM :
Sometimes call to Inet6AddressImpl.lookupAllHostAddr hangs up for a long time (more than 3 hours) thread and other threads which tries to resolve the same domain name. Domain name is valid. In the same time (before, concurrently and when thread is hang-up) other calls with other domain names works without any troubles. Problem happens very rarely (1-2 times in a year) but made big troubles. After application restart problem disappears.

DNS cache TTL is system-default.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Concurrently call Inet6AddressImpl.lookupAllHostAddr long time with different domains.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
UnknownHostException after system-configured timeout.
ACTUAL -
Thread is waiting answer for a long time. More than 3 hours.

ERROR MESSAGES/STACK TRACES THAT OCCUR :
"Thread-1761" #1057139 daemon prio=5 os_prio=0 tid=0x00007f3bac321000 nid=0x2ee9 runnable [0x00007f3c6c3f9000]
   java.lang.Thread.State: RUNNABLE
at java.net.Inet6AddressImpl.lookupAllHostAddr(Native Method)
at java.net.InetAddress$2.lookupAllHostAddr(InetAddress.java:907)
at java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1302)
at java.net.InetAddress.getAllByName0(InetAddress.java:1255)
at java.net.InetAddress.getAllByName(InetAddress.java:1171)
at java.net.InetAddress.getAllByName(InetAddress.java:1105)
at org.apache.http.impl.conn.SystemDefaultDnsResolver.resolve(SystemDefaultDnsResolver.java:44)


"Thread-1766" #1058324 daemon prio=5 os_prio=0 tid=0x00007f3bac2c5800 nid=0x3c05 in Object.wait() [0x00007f3b0c7cf000]
   java.lang.Thread.State: WAITING (on object monitor)
at java.lang.Object.wait(Native Method)
at java.lang.Object.wait(Object.java:502)
at java.net.InetAddress.checkLookupTable(InetAddress.java:1372)
- locked <0x00000005d08732f0> (a java.util.HashMap)
at java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1289)
at java.net.InetAddress.getAllByName0(InetAddress.java:1255)
at java.net.InetAddress.getAllByName(InetAddress.java:1171)
at java.net.InetAddress.getAllByName(InetAddress.java:1105)
at org.apache.http.impl.conn.SystemDefaultDnsResolver.resolve(SystemDefaultDnsResolver.java:44)


"Thread-1771" #1058832 daemon prio=5 os_prio=0 tid=0x00007f3bac360800 nid=0x43f4 in Object.wait() [0x00007f3b0bbc3000]
   java.lang.Thread.State: WAITING (on object monitor)
at java.lang.Object.wait(Native Method)
at java.lang.Object.wait(Object.java:502)
at java.net.InetAddress.checkLookupTable(InetAddress.java:1372)
- locked <0x00000005d08732f0> (a java.util.HashMap)
at java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1289)
at java.net.InetAddress.getAllByName0(InetAddress.java:1255)
at java.net.InetAddress.getAllByName(InetAddress.java:1171)
at java.net.InetAddress.getAllByName(InetAddress.java:1105)
at org.apache.http.impl.conn.SystemDefaultDnsResolver.resolve(SystemDefaultDnsResolver.java:44)


"Thread-1776" #1058858 daemon prio=5 os_prio=0 tid=0x00007f3bac361000 nid=0x44a2 in Object.wait() [0x00007f3c950da000]
   java.lang.Thread.State: WAITING (on object monitor)
at java.lang.Object.wait(Native Method)
at java.lang.Object.wait(Object.java:502)
at java.net.InetAddress.checkLookupTable(InetAddress.java:1372)
- locked <0x00000005d08732f0> (a java.util.HashMap)
at java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1289)
at java.net.InetAddress.getAllByName0(InetAddress.java:1255)
at java.net.InetAddress.getAllByName(InetAddress.java:1171)
at java.net.InetAddress.getAllByName(InetAddress.java:1105)
at org.apache.http.impl.conn.SystemDefaultDnsResolver.resolve(SystemDefaultDnsResolver.java:44)


"Thread-1781" #1060162 daemon prio=5 os_prio=0 tid=0x00007f3b20240000 nid=0x5294 in Object.wait() [0x00007f3c955dd000]
   java.lang.Thread.State: WAITING (on object monitor)
at java.lang.Object.wait(Native Method)
at java.lang.Object.wait(Object.java:502)
at java.net.InetAddress.checkLookupTable(InetAddress.java:1372)
- locked <0x00000005d08732f0> (a java.util.HashMap)
at java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1289)
at java.net.InetAddress.getAllByName0(InetAddress.java:1255)
at java.net.InetAddress.getAllByName(InetAddress.java:1171)
at java.net.InetAddress.getAllByName(InetAddress.java:1105)
at org.apache.http.impl.conn.SystemDefaultDnsResolver.resolve(SystemDefaultDnsResolver.java:44)


"Thread-1786" #1062811 daemon prio=5 os_prio=0 tid=0x00007f3bac363800 nid=0x716b in Object.wait() [0x00007f3b0b4bc000]
   java.lang.Thread.State: WAITING (on object monitor)
at java.lang.Object.wait(Native Method)
at java.lang.Object.wait(Object.java:502)
at java.net.InetAddress.checkLookupTable(InetAddress.java:1372)
- locked <0x00000005d08732f0> (a java.util.HashMap)
at java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1289)
at java.net.InetAddress.getAllByName0(InetAddress.java:1255)
at java.net.InetAddress.getAllByName(InetAddress.java:1171)
at java.net.InetAddress.getAllByName(InetAddress.java:1105)
at org.apache.http.impl.conn.SystemDefaultDnsResolver.resolve(SystemDefaultDnsResolver.java:44)


"Thread-1791" #1063142 daemon prio=5 os_prio=0 tid=0x00007f3b7c171800 nid=0x754d in Object.wait() [0x00007f3c949d8000]
   java.lang.Thread.State: WAITING (on object monitor)
at java.lang.Object.wait(Native Method)
at java.lang.Object.wait(Object.java:502)
at java.net.InetAddress.checkLookupTable(InetAddress.java:1372)
- locked <0x00000005d08732f0> (a java.util.HashMap)
at java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1289)
at java.net.InetAddress.getAllByName0(InetAddress.java:1255)
at java.net.InetAddress.getAllByName(InetAddress.java:1171)
at java.net.InetAddress.getAllByName(InetAddress.java:1105)
at org.apache.http.impl.conn.SystemDefaultDnsResolver.resolve(SystemDefaultDnsResolver.java:44)



REPRODUCIBILITY :
This bug can be reproduced rarely.

CUSTOMER SUBMITTED WORKAROUND :
We made our own lookup method which add timeout processing. But there is a lot of places where this solution is impossible integrate to.

@Override
public InetAddress[] resolve(String host) throws UnknownHostException {
Future<InetAddress[]> f = Executors.newSingleThreadExecutor().submit(new Callable<InetAddress[]>() {
@Override
public InetAddress[] call() throws Exception {
return InetAddress.getAllByName(host);
}
});

try {
return f.get(timeout, TimeUnit.MILLISECONDS);
} catch (TimeoutException e) {
throw new UnknownHostException("Time out of waiting response from DNS server");
} catch (InterruptedException e) {
throw new RuntimeException("Thread has been interrupted");
} catch (ExecutionException e) {
if (null != e.getCause() && e.getCause() instanceof UnknownHostException) {
throw (UnknownHostException)e.getCause();
}

if (null != e.getCause() && e.getCause() instanceof RuntimeException) {
throw (RuntimeException)e.getCause();
}
throw new RuntimeException("Impossible exception cause", e);
}
}


SUPPORT :
YES