PK94104: SIP CONTAINER CACHES DNS ENTRIES FOREVER

Fixes are available

APAR status

Closed as program error.

Error description

The Session Initiation Protocol (SIP) container caches a DNS
query indefinitely ignoring the Time To Live DNS value in the
answer.

Local fix

Problem summary

****************************************************************
* USERS AFFECTED:  Session Initiation Protocol (SIP) users of  *
*                  IBM WebSphere Application Server V6.1 and   *
*                  V7.0                                        *
****************************************************************
* PROBLEM DESCRIPTION: The SIP container caches the result     *
*                      of a DNS query for the entire process   *
*                      lifetime.                               *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
The SIP container caches DNS results, in addition to the DNS
cache that the underlying JRE (Java Runtime Environment)
maintains.
The default policy of the JRE is to keep DNS results in cache
for the entire process lifetime. This policy is configurable
in the standard networking properties of the JRE.
The problem occurs when the administrator modifies the DNS
cache policy of the JRE. The SIP container ignores the JRE
cache policy, and caches DNS results forever. This can cause a
problem when the application sends two messages to the same
destination host name, and the DNS record of that host name
changes in between the two messages. For example, the
application sends a message to sip.example.com, and a few
minutes later sends another message to the same address. In
between the two messages, the IP address of sip.example.com
was changed. Because the IP address was cached in the first
message, there is no DNS query when sending the second,
resulting in the second message going to the old address.

Problem conclusion

The problem is fixed in the SIP container. With this fix, DNS
results are cached in the container for the same amount of
time as specified in the configuration settings of the Java
Runtime Environment.

The fix for this APAR is currently targeted for inclusion in
fix pack 6.1.0.29 and 7.0.0.9.  Please refer to the Recommended
Updates page for delivery information:
http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980

Temporary fix

Comments

APAR Information

APAR number
PK94104
Reported component name
WEBS APP SERV N
Reported component ID
5724H8800
Reported release
700
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2009-08-18
Closed date
2009-08-25
Last modified date
2009-08-28

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

PM00698

Fix information

Fixed component name
WEBS APP SERV N
Fixed component ID
5724H8800

Applicable component levels

R61A PSY
UP
R61H PSY
UP
R61I PSY
UP
R61P PSY
UP
R61S PSY
UP
R61W PSY
UP
R61Z PSY
UP
R700 PSY
UP

[{"Business Unit":{"code":"BU059","label":"IBM Software w\/o TPS"},"Product":{"code":"SSEQTP","label":"WebSphere Application Server"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"7.0","Line of Business":{"code":"LOB45","label":"Automation"}}]

Document Information

Modified date:
29 December 2021

Tips

PK94104: SIP CONTAINER CACHES DNS ENTRIES FOREVER

Fixes are available

Subscribe

APAR status

Closed as program error.

Error description

Local fix

Problem summary

Problem conclusion

Temporary fix

Comments

APAR Information

APAR number

Reported component name

Reported component ID

Reported release

Status

PE

HIPER

Special Attention

Submitted date

Closed date

Last modified date

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

Fixed component ID

Applicable component levels

R61A PSY

R61H PSY

R61I PSY

R61P PSY

R61S PSY

R61W PSY

R61Z PSY

R700 PSY

Document Information

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