PK75700: DCS_UNICAST_ADDRESS PORT CONFLICT RESULTS IN HMGR0028E, DCSV1036W AND EVENTUALLY JAVA OUTOFMEMORYERROR IN THE SERVER.

Fixes are available

APAR status

Closed as program error.

Error description

When running a configured new server with an already
'in-use' port for the DCS_UNICAST_ADDRESS, the HA manager will
detect the port conflict by issuing HMGR0028E messages.

The HA Manager communication amongst these server will
eventually result in Java OutOfMemoryError for the control
region.  When checked the heap had lots of DCS Alarm() objects.

The heap usage looked something like this.

SECTION       MEMINFO subcomponent dump routine
NULL           =================================
1STHEAPFREE    Bytes of Heap Space Free: 105ae58
1STHEAPALLOC   Bytes of Heap Space Allocated: 10000000

total count 6540141 total links 13350393 total size 322782744
Summary of heap usage by class
Total size   Instance size   Count     Class
----------   -------------   -----     -----
77171640     56              1378065
com/ibm/ws/dcs/utils/AlarmImpl$AlarmTask
66150144     48              1378128   com/ibm/ejs/util/am/
_Alarm
66147120     48              1378065   com/ibm/ws/dcs/utils/
WASAlarmImpl
33148896     24              1381204   java/lang/Object
16849432     varies          20360     array of byte
16010560     varies          162446    array of char
7651120      40              191278    java/lang/String
5506144      varies          2         array of java/lang/Compar
3043120      40              76078     java/util/HashMap$Entry
1936440      40              48411     java/util/LinkedList$Entr

The control region had messages like below.

Exception in thread "WebSphere t=009c0460" JVMDUMP006I
Processing Dump Event "systhrow", detail
"java/lang/OutOfMemoryError" - Please Wait.

Trace: 2008/10/19 03:49:23.300 01 t=9FF028 c=UNK key=S2 (1300700
   ThreadId: 0000000a
   FunctionName: com.ibm.ws.hamanager.coordinator.dcs.
   CoreStackMembershipManager
   SourceId:com.ibm.ws.hamanager.coordinator.dcs.CoreStack
   MembershipManager
   Category: SEVERE
   ExtendedMessage: BBOO0220E: HMGR0028E: A duplicate
DCS_UNICAST_ADDRESS port has been detected. Members WS\NA1B\
WSIN1H and WS\NWSIS1B on host abc.xyz.com are both configured
to use port 10121.

Which generated lots of 'alarm()'s

Trace: 2008/10/19 04:13:33.085 01 t=9C9840 c=UNK key=S2 (1300700
   ThreadId: 00000010
   FunctionName:com.ibm.ws.dcs.vri.transportAdapter.rmmImpl.
   ptpDiscovery.DiscoveryServerMgr
   SourceId:com.ibm.ws.dcs.vri.transportAdapter.rmmImpl.ptp
   Discovery.DiscoveryServerMgr
   Category: WARNING
   ExtendedMessage: BBOO0221W: DCSV1036W: DCS Stack
   DefaultCoreGroup at Member WS\NA1A\WSIS6A: An unusual
   connectivity state occurred with member WS\NA1A\WSIN1G,
   details: alarm(): Closing the connection because members
   did not manage to connect.

Local fix

Create Appplication Server/s using unique ports.

Problem summary

****************************************************************
* USERS AFFECTED:  All users of WebSphere Application Server   *
*                  V6.1.0 for z/OS                             *
****************************************************************
* PROBLEM DESCRIPTION: DCS views will be continually applied   *
*                      if a user configures multiple           *
*                      processes to use the same port for      *
*                      the DCS_UNICAST_ENDPOINT.A HMGR0028     *
*                      message will indicate which members     *
*                      have conflicts.                         *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
If multiple processes on the same host are configured to use
the same port for the DCS_UNICAST_ENDPOINT, all core group
processes will have problems communicating due to the
conflict. This is due to the fact that DCS assumes that the
combination of IP and port is unique for all core group
members.
For example, lets say both processes A and B are at the same IP
address and port, but only one of the processes is
running. Now when process C is starting up, it attempts to
open connections to both processes A and B. Process C fails to
recognize that both process A and B are configured on the same
IP:port.

Problem conclusion

To prevent continual views from being applied, DCS will not
open a connection to processes that have a conflicting IP:port
combination.

APAR PK75700 is currently targeted for inclusion in
Service Level (Fix Pack) 6.1.0.25 of WebSphere
Application Server V6.1 for z/OS.

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
PK75700
Reported component name
WEBSPHERE FOR Z
Reported component ID
5655I3500
Reported release
610
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2008-11-14
Closed date
2009-03-31
Last modified date
2009-07-01

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

PK75701 PK75702

Fix information

Fixed component name
WEBSPHERE FOR Z
Fixed component ID
5655I3500

Applicable component levels

R610 PSY UK47214
UP09/06/22 P F906

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":"BU059","label":"IBM Software w\/o TPS"},"Product":{"code":"SS7K4U","label":"WebSphere Application Server for z\/OS"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"6.1","Line of Business":{"code":"LOB45","label":"Automation"}}]

Document Information

Modified date:
29 December 2021

Tips

PK75700: DCS_UNICAST_ADDRESS PORT CONFLICT RESULTS IN HMGR0028E, DCSV1036W AND EVENTUALLY JAVA OUTOFMEMORYERROR IN THE SERVER.

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

R610 PSY UK47214

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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