A fix is 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 V7.0 * **************************************************************** * 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 PM49734 is currently targeted for inclusion in Service Level (Fix Pack) 7.0.0.21 of WebSphere Application Server V7.0. 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
PM49734
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
2011-10-10
Closed date
2011-12-13
Last modified date
2012-02-03
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 UK74996
UP12/01/18 P 1201
Fix is available
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Document Information
Modified date:
10 February 2022