IZ80189: When DNS server has mulitple IP addresses for the same domain name, Java is returning a subset of them.

APAR status

• Closed as program error.

Error description

• Error Message:
  The java parameters used to disable network address caching are
  being ignored on the IBM JDK 1.6 SR7. These parameters
  previously worked on 1.6 SR5
  The parameters used are :
       -Dsun.net.inetaddr.ttl=0 -Dnetworkaddress.cache.ttl=0
  
  The problem can be easily reproduced using a simple test
  program that queries the DNS.  In a test setup which
  expect the java program to round robin between two different
  IP addresses, Java 6 SR7 return only one IP address where as
  Java 6 SR5 return both the IP address.
  .
  Output from the test program using SR7 JDK -
  /opt/WAS7.0/64bit/java/bin/java -Djava.net.preferIPv4Stack=true
  -Dsun.net.inetaddr.ttl=0 -Dnetworkaddress.cache.ttl=0
  DNSTester specdelivery 500
  192.168.18.119: 500
  Number of unique IP Addresses returned : 1
  Time to look up 500 IPs : 0.21 seconds
  .
  Output from the test program using SR5 JDK -
   /opt/7005_cf050926.18/java/bin/java
  -Djava.net.preferIPv4Stack=true -Dsun.net.inetaddr.ttl=0
  -Dnetworkaddress.cache.ttl=0   DNSTester specdelivery 500
  192.168.18.119: 250
  192.168.9.119: 250
  Number of unique IP Addresses returned : 2
  Time to look up 500 IPs : 0.125 seconds
  .
  Stack Trace: N/A
  .
  NA
  

Local fix

• NA
  

Problem summary

• The java parameters used to disable network address caching are
  being ignored on the IBM JDK 1.6 SR7. These parameters
  previously worked on 1.6 SR5
  The parameters used are :
       -Dsun.net.inetaddr.ttl=0 -Dnetworkaddress.cache.ttl=0
  When DNS server has mulitple IP addresses for the same domain
  name, Java is returning a subset of them.
  Expected result is to retrieve all the IP Addresses
  

Problem conclusion

• This defect will be fixed in:
  6.0.0 SR8
  .
  A simple method trace in the passing and failing case revealed
  that a additional loookup call being made in InetAddress.java.
  This piece was introduced via WRT code. and is not applicable
  for normal SE.
  .
  To obtain the fix:
  Install build 20100514 or later
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Fix information

• Fixed component name

  JAVA CLASS LIBS

• Fixed component ID

  620700130

Applicable component levels

• R600 PSN

     UP