A fix is available
APAR status
Closed as new function.
Error description
New Function.
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: Users of z/OS 1.4 (HBB7707) and above. * **************************************************************** * PROBLEM DESCRIPTION: WLM provides queue/server management * * application interfaces which allow * * applications to pass work requests from * * an application daemon to work regions * * which process the requests. WLM * * internally queues the work requests * * based on the classification to service * * class queues and manages the server * * regions based on the goal definitions * * for the service classes, the goal * * achievement and demand. DB2 is one * * example which exploits these interfaces * * for getting management of their stored * * procedures address spaces by WLM. In * * order to allow WLM to manage the server * * address spaces, the customer has to * * define an application environment and * * must provide the start procedure which * * is used by WLM to start the server * * regions. From a DB2 perspective, a WLM * * application environment encapsulates a * * certain DB2 function or a set of DB2 * * stored procedures with similar * * characteristics. * * * * The underlying assumption for this * * processing is that the work requests * * are independent of each other. For DB2 * * Stored Procedures, this is not true in * * all occasions. There are two scenarios * * where work requests are dependent on * * each other which can cause troubles to * * the way WLM manages the server regions: * * * * 1.) A stored procedure which is * * processed by a server task in a WLM * * managed stored procedure address space * * inserts another work request (another * * stored procedure) and waits until it * * completes its processing. The server * * task is suspended and can't select any * * other work until the dependent stored * * procedure has finished its processing. * * It is possible that multiple recursions * * can occur in such a sequence which * * suspend all server tasks except the * * last one and therefore reduce the * * capability of the server address space * * to process work in parallel. * * * * 2.) A DB2 User Defined Function inserts * * a sequence of work requests which then * * process sequentially. The insertion * * takes place one after another. After * * the first stored procedure has been * * inserted the server task suspends and * * wakes up the application task which * * inserts the next stored procedure. * * After all requests have been inserted, * * the server tasks are resumed by DB2 to * * process data. DB2 will only wake up one * * task so that all process in a sequence. * * Another facet of this processing is * * that it is possible that the * * application task inserts the work * * requests to different WLM application * * environments, in case it needs * * different DB2 functions or types of * * stored procedures. * * * * Existing customer situation showed that * * these situations caused timeouts for * * the customer applications using DB2 * * UDFs and stored procedures and thus * * causing unexpected trouble to the * * customer environment. * **************************************************************** * RECOMMENDATION: * **************************************************************** WLM support is needed to allow applications to inform WLM that a work request with a dependency to other work already in progress is inserted. When such dependent work requests are queued for extended periods of time WLM needs to help the applications by adding server address spaces as long as the system resources and service class goals support this.
Problem conclusion
Temporary fix
Comments
The WLM queue/server management application interfaces will be changed by this SPE to allow an application to inform WLM that a work request with a dependency to other work already in progress is inserted. To support this the new DEPENDENT=YES|NO keyword is added to the IWMQINS and IWM4QIN service. The default for the new keyword is DEPENDENT=NO. A request with DEPENDENT=YES is prioritized above requests which are not marked as dependent. WLM will also recognize situations with dependent requests queued for extended periods of time and try to help these applications by adding server address spaces as long as the system resources and service class goals support this. This also means that the ability of WLM to help such applications is limited by the amount of available system resources and goal settings for the application. . This apar also adds support for the SPM qualifier for subsystem DDF.
APAR Information
APAR number
OA04555
Reported component name
WORK LOAD MANAG
Reported component ID
5752SCWLM
Reported release
708
Status
CLOSED UR1
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2003-08-27
Closed date
2004-05-27
Last modified date
2006-01-03
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UA11154 UA11155 UA11156
Modules/Macros
IRACONST IRAEASQE IRAPACA3 IRAPADRV IRAPAHK4 IRAPAQPP IRAPAQP2 IRAPAQUE IRAQUEUE IRAQUSAM IRARADRV IRARMCTY IRASAMSU IWMATSSQ IWME2ASC IWME2DRG IWME2LCP IWME2QXT IWME2REG IWME2SRM IWMH7C9 IWMH7DF IWMI2NUC IWMQINS IWMQINSP IWMQUSA IWMQ2DAE IWMQ2DEL IWMQ2DIS IWMQ2FIX IWMQ2INS IWMQ2SAM IWMQ2SEL IWMQ2VEE IWMQ2VEQ IWMZ2VQE SGISRM
| SA22761900 |
Fix information
Fixed component name
WORK LOAD MANAG
Fixed component ID
5752SCWLM
Applicable component levels
R707 PSY UA11154
UP04/06/09 P F406
R708 PSY UA11155
UP04/06/09 P F406
R717 PSY UA11156
UP04/06/09 P F406
Fix is available
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