Controller and Servant WLM classifications

Applications are deployed on a server or a cluster of servers. Each server consists of a controller and one or more servants. Each controller is started by the deployment manager, or by an MVS operator command as an MVS started tasks. Each servant is started by the workload manager (WLM) as it is needed.

You can use transaction classes to classify client workload for WLM. Transaction classification can be based on the following WLM classification criteria:

.

Controller classification

You should classify controllers in SYSSTC or give them a high importance and velocity goal, because contollers do some of the processing that is required to receive work into the system, manage the HTTP transport handler, classify the work, and do other housekeeping tasks,

Note: A step in controller start-up procedures, such as BBO5ACR, invoke the BPXBATCH program to check the service levels delivered, applied, and pending, and log the results in the /properties/service/logs/applyPTF.log file. Because the BPXBATCH program is classified according the OMVS rules, instead of inheriting the service classification of the startup procedure, on a busy system several minutes might pass before BBOCTL gets control. You can minimize the impact of the BPXBATCH step by changing the WLM Workload Classification Rules for OMVS work to a higher service objective. In the following example, OMVS work is assigned a EBIZ_HI service class, which has an importance of 1, and Velocity of 50.

Subsystem Type . : OMVS
Description . . . E_Biz Classification Rule
--------Qualifier------ -------Class--------
Action Type Name Start Service Report
DEFAULTS: EBIZ_DEF ________
____ 1 TN FTPSERVE ___ EBIZ_HI ________
____ 1 UI OMVSKERN ___ SYSSTC ________
____ 1 TN WSSRV* ___ EBIZ_HI RPTACR <<==

Servant classification

You should classify servants to a high STC importance service class so that they can be initialized quickly when WLM determines they are needed. The service class chosen also determines the WLM goal when other work such as Java Garbage Collection (GC) which are not part of the enclave work that can be running, and can be CPU intensive. Also, any threads that are spun off in the servant that do not run under the enclave, run under the servant’s classification.

Note: Do not set the servant classification higher in the service class hierarchy than more important work, such as production enclaves, CICS, or IMS transaction servers.

WLM Classification Rules for STC-type work

Here is a simple example of the WLM Classification Rules for STC-type work that covers the controller and servant started tasks:

          --------Qualifier--------           -------Class-------- 
Action    Type     Name     Start             Service     Report  
                                    DEFAULTS: OPS_DEF     ________
_____  1  TN      %%DMN    ___                OPS_HIGH    RWSDMN _____  1  TN      T5SRV*   ___                OPS_MED     RT5SRV
_____  1  TN      WS%%%%   ___                SYSSTC      RWSCTLR 
 ____  1  TN      WS%%%%S  ___                OPS_HIGH    RWSSRVR




Searchable topic ID:   rweb_classervers
Last updated: Jun 21, 2007 9:56:50 PM CDT    WebSphere Application Server for z/OS, Version 5.0.2
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