PM17126: DURING CONTROL REGION STARTUP A POSSIBLE LOOP OR HANG CAN OCCUR.

Fixes are available

APAR status

Closed as program error.

Error description

During Control Region startup a possible loop or hang can occur
in HashMap.findNonNullKeyEntry, from
com/ibm/ws/xcf/groupservices/NameConverterZos.short2longName
.
The symptom will be a showing of HashMap.findNonNullKeyEntry and
com/ibm/ws/xcf/groupservices/NameConverterZos.short2longName
from thread dumps.
.
In summary, the stack from the dump will look like this:
java/util/HashMap.findNonNullKeyEntry
java/util/HashMap.getEntry
java/util/HashMap.get
com/ibm/ws/xcf/groupservices/NameConverterZos.short2longName
com/ibm/ws/xcf/groupservices/GenLivenessPluginZoS.notifyMemberIn
fo
com/ibm/ws/xcf/groupservices/GenLivenessServiceXCF.notifyMemberI
nfo

Local fix

Problem summary

****************************************************************
* USERS AFFECTED:  All users of IBM WebSphere Application Server
*                  V7.0                                        *
****************************************************************
* PROBLEM DESCRIPTION: During Control Region startup a loop    *
*                      or hang can occur in Hashmaps used by   *
*                      the NameCoverterZos class.              *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
During the Control Region startup, a loop or hang may occur. A
Java stacktrace from the dump of the Control Region may show
one or more threads executing HashMap methods called from the
NameConverterZos class similar to the following:

java/util/HashMap.findNonNullKeyEntry
java/util/HashMap.getEntry
java/util/HashMap.get
com/ibm/ws/xcf/groupservices/NameConverterZos.short2longName
com/ibm/ws/xcf/groupservices/GenLivenessPluginZoS.notifyMemberIn
fo
com/ibm/ws/xcf/groupservices/GenLivenessServiceXCF.notifyMemberI
nfo

The problem occurs because the use of HashMaps in the
NameConverterZos class is not properly synchronized. During
periods of heavy use, such as server startup, concurrent
attempts to update a HashMap can cause a number of exceptions
or other error conditions.

Problem conclusion

The NameConverterZos class has been changed so that methods
that read or update the HashMaps are synchronized to insure
that multiple threads do not access HashMaps concurrently.

Consideration should also be given to applying SDK APAR
IZ73767, which fixes a related, but wider, problem with
HashMap multi-threading.

APAR PM17126 is currently targeted for inclusion in
Service Level (7.0.0.13) of WebSphere Application Server

Please refer to URL:
//www.ibm.com/support/docview.wss?rs=404&uid=swg27006970
for Fix Pack availability.

Temporary fix

Comments

APAR Information

APAR number
PM17126
Reported component name
WEBSPHERE FOR Z
Reported component ID
5655I3500
Reported release
700
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2010-06-23
Closed date
2010-08-24
Last modified date
2010-11-02

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
WEBSPHERE FOR Z
Fixed component ID
5655I3500

Applicable component levels

R700 PSY UK61146
UP10/10/21 P F010

Fix is available

Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.

[{"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SS7K4U","label":"WebSphere Application Server for z\/OS"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"7.0","Line of Business":{"code":"LOB45","label":"Automation"}}]

Document Information

Modified date:
24 October 2021

Tips

PM17126: DURING CONTROL REGION STARTUP A POSSIBLE LOOP OR HANG CAN OCCUR.

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

R700 PSY UK61146

Fix is available

Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.

Document Information

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