PM46270: WHEN USING MVS LOGSTREAMS FOR WEBSPHERE APP SERVER ERROR LOGS SERVANT MAY CONNECT TO LOGSTREAM MULTIPLE TIMES AND USE HIGH SQA

Fixes are available

APAR status

Closed as program error.

Error description

When WebSphere Application Server is configured to use the z/OS
Logstream for recording of it's 'error log' information, it
uses the z/OS Logger utility.
The WebSphere Application Servant region Address Space will
connect to the Logstream (IXGCONN) and then Write (IXGWRITE) to
the Logstream.
Logger limits the number of writes that any one connection can
have in it's 'write queue'.  Each of the 'queued writes' is
backed by SQA Storage in the z/OS System.
It has been found that the WebSphere Servant Regions may
'connect' multiple times.  If Logger is not able to process the
'Writes' that are queued to it, SQA Storage will be used to hold
the SRB';s associated with the queued messages.
Depending on system configuration and availability of common
storage on the system, this queue of SRB's may cause an SQA
Storage Shortage on the System.

This apar will also change the handling of some error/warning
codes that are returned from Logger. For example when
RC=00000004, RSN=00000407 is returned, WebSphere will log a
message that there has been a possible loss of data, but it will
continue writing to the logstream instead of current design of
disconnecting from the logstream and sending the messages to
CERR instead.

Local fix

If it is determined that an SQA Storage shortage is caused by
Logger queue of SRB's from the WebSphere Servant Region Address
Space, then the WebSphere configuration can be changed to not
use Logstream for it's 'error log'
The WebSphere variable that is set to point to a Logstream is:
    ras_log_logstreamName
If this is set to point to a Logstream dataset name, you can
simply remove this variable, and re-start the WebSphere Server
to pick up the change.

Problem summary

****************************************************************
* USERS AFFECTED:  All users of IBM WebSphere Application      *
*                  Server V6.1.0 and V8.0.                     *
****************************************************************
* PROBLEM DESCRIPTION: WebSphere Application Server for z/OS   *
*                      makes multiple concurrent connections   *
*                      to the errorlog logstream.              *
*                      Also, WebSphere stops writing to the    *
*                      errorlog logstream when it receives a   *
*                      IXGCONN RC=00000004 and RSN=00000407.   *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
The WebSphere errorlog logstream (ras_log_logstreamName)
implementation does not interpret various IXGWRITE and IXGCONN
return and reason codes correctly.
This can lead to a WebSphere address with multiple connections
to the logstream.   This can negate the restriction of
outstanding IXGWRITE requests.  Exceeding the limit for
outstanding IXGWRITE requests can exhaust system resources,
such as storage.  ABENDS878 RC=4 was observed for a case were
the previous condition ran the system out of SQA storage.
Another observed scenario resulted from an incorrect handling
of the IXGCONN RC=4, RSN=407.  In this case, WebSphere stopped
directing messages to the logstream.  Instead the messages
were written to the default message location (typically CERR).

Problem conclusion

Code has been modified to properly re-act to the IXGWRITE and
IXGCONN return and reason codes.  WebSphere will properly
recognize when our logstream connection has been lost and only
then re-connect based on the IXG reason codes.

APAR PM46270 is currently targeted for inclusion in Service
Level (Fix Pack) 6.0.0.43 of WebSphere Application Server V6.1.0
and Fix Pack 8.0.0.2 of WebSphere Application Server V8.0.

The fix will also be delivered as sysrouted APAR PM49734 in
WebSphere Application Server V7.0 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
PM46270
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
2011-08-23
Closed date
2011-10-11
Last modified date
2012-04-03

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

PM49734

Fix information

Fixed component name
WEBSPHERE FOR Z
Fixed component ID
5655I3500

Applicable component levels

R610 PSY UK76696
UP12/03/18 P F203

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:
27 October 2021

Tips

PM46270: WHEN USING MVS LOGSTREAMS FOR WEBSPHERE APP SERVER ERROR LOGS SERVANT MAY CONNECT TO LOGSTREAM MULTIPLE TIMES AND USE HIGH SQA

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 UK76696

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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